# Mark's Monitor Build



## dnalot (Apr 15, 2022)

Marks Monitor Build

A little history can be found here     USS Monitor - Wikipedia

The Iron Clad USS Monitor was designed and built by John Ericson for the US Navy during the American civil war. The contract required the ship to be built in less than 100 days for a cost of $225,000 with a money back guarantee if the ship was late or did not perform as advertised. I found conflicting information on how long it took to build the ship but 118 days was the most likely. And it more than met expectations.

Its historic match-up ( Battle of Hampton Roads ) against the Confederate Iron clad Virginia (Merrimack) lasted 4 hours and ended in a draw.

The ship later sank in a storm with the loss of 16 of its 49 man crew. The engine was recovered in 2001 and has been undergoing cleaning and conservation.

The engine is described as a Vibrating Lever-Half Trunk Steam engine. It weighted 30 tons and produced 400 HP. The unusual design allowed for a very low profile keeping the engine below water line. One of the more interesting elements of this engine was the reversing design.

A full set of drawings were produced by Mr R. W. Carlsedt after 20 years of research. The drawings are in full scale and he has made these drawings available at no cost.

Find the excellent drawings by R. W. Carlstedt here   https://homeshopmachinist.net/resources/downloads/

Find an introduction to Mr Carlstedt and his fine model of the USS Monitors Engine here  USS Monitor Engine

Find a YouTube video of Mr Carstedt's model here 

Mr Carlsedt's model was in 1/16 scale. Mine will be a bit larger because of my old arthritic fingers.  Surprisingly (with the time limit) the castings of the original engine had some fancy embellishments.

To make this part and a few other hard to make parts I decided I would need to cast them. So for five months I have been learning how to do investment casting. First I learned how to use a 3D cad program (Fusion 360), Bought 2 3D resin printers and learned how to print 3D patterns with a special casting resin and made a kiln to burn out the pattern. I bought an electric smelter to melt my metal. And I bought vacuum chamber and a pressure pot for getting the air out of the plaster investment.

Everything was a struggle. But after a lot of effort getting my equipment to work properly and a lot of trial and error I have finally started to get some decent results. I have been doing sand casting for many years but this investment casting is a world apart in complexity. But the results are well worth the effort. When everything goes to plan the rough cast parts are well beyond anything I was ever able to do before.

There are NO SHORTCUTS in investment casting. If you plan on giving it a try. Get your wallet out. As a n example a 50 pound box of investment powder cost $44. With shipping and sales tax it came to $162. I tried using scrap metal but could not get repeatable results so I had to buy brass beads made for investment casting $120 for 10 pounds but boy was it worth it. 3D resin for casting is expensive even if you use the lower cost brands. Even the flask deteriorates quickly. Make one mistake and it will cost you $$$ and a lot of time.

Here is a link to my Build of a burnout oven or Kiln https://www.homemodelenginemachinist.com/threads/marks-kiln-build.33783/

Here is a link to my first try at Investment casting. It will show you my setup and equipment.

Mark's First investment casting

Look at the top of post number 1, on the right side corner, click on the word “watch”. Now you will get a notification whenever there is any activity on this thread. Comments are welcomed. Kriticize  my speeling and gramor if you like, it dosen't bother me.

This photo shows the difference in scale between Mr. Carstedt's Model and the one I am building.







Mark T


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## johnmcc69 (Apr 15, 2022)

Beautiful castings! It looks like all your time & efforts have been rewarded.

 Looking forward to this!

 John


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## dnalot (Apr 16, 2022)

This is a failed part that was cast in a flask that was too hot. The metal was to hot and the burnout was not complete.







Here is another failed part. This one the flask was to cold, metal was to hot and the burnout was not complete. 






Eventually I started to get better results. One big problem I had was caused by my using the metal from failed parts. With each melt the metal would lose some of the zinc and that would affect the melting temperature and how the metal would flow. Chased my own tail for awhile before I broke down and bought a 10 pound bag of brass beads made for casting. 

Mark T


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## dnalot (Apr 16, 2022)

Eventually I started getting usable parts. Here are the parts for the steam manifold. The elbows turned out OK, just a little surface issue on the flanges but a little sanding will fix that. The tube was a  failure. The small amount of layer marks left from printing the parts are largely removed with a light sandblasting.






The brighter parts here were cast in Bronze. The rest in Brass. The brass I am using is about 66 percent copper and 33 percent zinc. Smaller parts like these are easy to cast. Larger parts, especially the ones with sharp edges are more difficult to cast because thermal expansion tends to cause cracks in the plaster.





Mark T


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## dnalot (Apr 16, 2022)

These parts are the base of the steam chest. The valve surface will be milled flat and made smooth after the parts have been attached to the cylinders. I was thrilled to be able to cast these with the steam passages. The drawing shows a cutaway of the part.






Valve chest and cover.






Steam chest covers. The tiny bolt is a 2-48 with a smaller than normal tall nut. It was this part that decided if I would attempt this build. The decretive feature would have been very difficult for me to machine.






I am now working on turning the cylinders and will post again when that is completed.

Mark T


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## Richard Carlstedt (Apr 16, 2022)

Mark,
 I just found your postings and am very impressed with your work and progress- outstanding !
I had a smile on my face when I read and saw your Valve Chest challenges . Now that is a very tough part !
I spent 6 months trying to do the chests alone  and had 56 casting attempts --all failed so i switched to machining and fabrication .
I did the lost Wax route , but that was 20 years ago so and used the rubber mold technique .
Some of my failures looked exactly like yours. Also, you are dead on with the metal alloy mix.
I had various brass/bronze hoards of metal and I did not want parts on the engine to have different color metal, so I made a big melt of alloy Bronze (very little Zinc to loose) and made ingots to use for casting or machining. My attempts at casting were not successful so I made the chests from solid .
Here are a few pictures, first, the valve chest rubber mold and pattern for a lost wax attempt ( that failed and I gave up)and then I cast " Blocks" for machining that you see in the forth picture 
Please send me a email at grnbaystmr   gbonline.com 
FYI , I left a space above where the @ would go so I don't get spammed 
Nice work on a very complex engine !
Rich


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## davidyat (Apr 17, 2022)

*Mark, if I were to decide to make a Monitor engine, would it be possible to buy your CAD files for the intent of casting my parts also?
Grasshopper*


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## dnalot (Apr 17, 2022)

davidyat said:


> Mark, if I were to decide to make a Monitor engine, would it be possible to buy your CAD files for the intent of casting my parts also?
> Grasshopper



If you are referring to the 3D files I could give you the STL files ready for your slicing program.

Mark T


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## davidyat (Apr 17, 2022)

*Thank you. Yes, I would be interested in them. My email is: dyatsko3 gmail.com
I left out the @ between the 3 and g so the spammers can't get me
Grasshopper*


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## dnalot (Apr 17, 2022)

I have sent e-mail to both Mr Carlstedt and Davidyat. If you guys don't receive them let me know.

Mark T


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## davidyat (Apr 17, 2022)

Received.
Grasshopper


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## Richard Carlstedt (Apr 17, 2022)

Mark, I did not get a email in the last 24 hours

Rich


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## dnalot (Apr 17, 2022)

Hi Rich. I double checked the address and I got that right. So I did a cut and past of your address filling in the blank and sent again. If that doesn't work PM me and I will give you my address. 

Mark T


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## Richard Carlstedt (Apr 17, 2022)

OK, My boo-boo  Mark
I did receive a email yesterday and replied to you - Did you get it ?





I thought you sent me a second email at ( "Yesterday 9:01 PM)  which would be after my email
and that's why I said no.

So now I just received the same early email ( 2 nd time ) ?
This is fun !
Rich


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## dnalot (Apr 18, 2022)

Rich, I found your emails in my spam folder. It was great reading. I will respond tomorrow evening as I am on a road trip till then. 

Mark T


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## dnalot (Apr 19, 2022)

davidyat said:


> Mark, if I were to decide to make a Monitor engine, would it be possible to buy your CAD files for the intent of casting my parts also?
> Grasshopper



I sent you what I have so far. Good luck


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## davidyat (Apr 19, 2022)

*Thanks*


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## Robert Ritchie (Apr 20, 2022)

Mark your work, your effort, amazing!  Awaitng your next post!


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## dnalot (Apr 20, 2022)

Robert Ritchie said:


> Awaitng your next post!



OK

First let me thank all of those that have viewed this thread. Just checked and over 800 views so far.

And a special thanks to Mr Carstedt for dropping in and offering to share his experience and considerable knowledge of this engine.

I have been working on the cylinder. It was turned from 3” brass pipe. The inside bore was no work at all. The pipe had a perfectly round ID with no taper and a polished surface. The OD was a bit off center to the ID and had some bumps. I turned the pipe down to give a .09” wall thickness.






The engine has two cylinders so my pipe needed a bulkhead in the center. I'm not trying to replicate inside details that can not be seen. I cut two .15” thick disks. one fit the ID snugly and the other with a little clearance for solder to wick in. To hold the bulkhead (center head) I cut a bit of scrap to support the disks at the proper height in the pipe. I tinned all the surfaces to be soldered and then  use an oxy/acetylene torch to heat up the pipe and bulkhead for soldering. A short dip in a mild acid solution cleaned it up pretty well but it still need to be cleaned a bit further with a scotch-bright-pad.











Mark T


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## dnalot (Apr 20, 2022)

From there I moved the cylinder assembly to the mill to cut the steam ports. I test fit the bases for the steam chests. These parts and the other parts to be assembled to the cylinder will be bonded with JB weld. I don't want to heat the cylinders any more than I have already. And that will allow me to fit and bond the parts as I go. Over the years I have had many occasions to go to remote areas of Alaska to work on aircraft and boats. I never went without lots of JB Weld, duct tape, steel wire and a .22 for mosquitoes. This is the first time I have used it on a model engine.













The photo above is just a test fitting. Heating of the cylinder changed the color of the brass. The cylinder and steam chests will match when completed (I hope) 

Mark T


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## Robert Ritchie (Apr 21, 2022)

Oh yes, progress is great, pics, post and work superior!


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## dnalot (Apr 22, 2022)

Just a quick post. The base for the steam chest has been glued to the cylinder and all went well. Tested for leaks and all is tight.

Mounted the cylinder to  the mill and trued up the valve surfaces and then relieved the flanges to locate the steam chest in place. All the steam chest parts now stack up properly and are located (locked) in position for drilling and tapping the holes for the bolts that will hold everything together. I will wait for a new 2-56 tap and the appropriate drill bits before I move on with this step.

In the meantime I will be modeling the heads and a couple of other parts for casting.
























Mark T


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## Robert Ritchie (Apr 25, 2022)

Looking great!


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## darwenguy (Apr 26, 2022)

Looks like a realy interesting engine design. And your brass castings look amazing, well worth the effort.
Thanks for sharing.

Luke.


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## Geken (Apr 27, 2022)

Fabulous castings,great work Mark.

As a friend  of Rich Carlstedt and also a builder of a Monitor engine he made me aware of your post.
Can't wait to see this build to the finish.This looks like being an excellent model.I built my Monitor engine to 1/25.4"(1mm to 1") scale, as a lookalike of Rich Carlstedt's using plans from the internet and Rich's, many thanks to Rich.All parts were fabricated and not all are to scale,and some omitted for simplicity and size limitations.
Can be seen here..   

Geoff


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## dnalot (Apr 27, 2022)

Hi Geken

I found your video on You-Tube just yesterday. Played it over and over just to listen to the great sound ( the engine not the music, not that there is anything wrong with the music ). Nicely done. And I like your monkey (ape). 

Mark T


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## GreenTwin (Apr 27, 2022)

There were Monitor engine builds before Rich's build, but I must say Rich opened the door for many builds on this engine.
I consider Rich's build sort of the gold standard on Monitor builds, and he did a tremendous amount of research on this engine, in order to get it accurately built.
And Rich has seen the actual Monitor engine that was recovered from the ocean.
What a fantastic day that must have been.  It is quite rare to get to see such an historical piece.

And thanks to Rich for publishing his Monitor drawings; he did not have to do that, and he no doubt put a huge amount of time and effort into creating those drawings.

And lastely, Rich is just a downright super nice guy; I have met him; and he gladly shares any information he has.
Hats off to Rich for kicking off a Monitor building spree in the hobby !!!  Who knows how many Monitors will get built.

Pat J


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## Robert Ritchie (Apr 27, 2022)

Looking great, great progress, can't wait to see in run!  Great post!


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## Gedeon Spilett (Apr 28, 2022)

lot of skills in these builds, thanks to share!
this engine looks great, i'm anxious to see the progresses.


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## stanstocker (Apr 28, 2022)

dnalot said:


> Hi Geken
> 
> I found your video on You-Tube just yesterday. Played it over and over just to listen to the great sound ( the engine not the music, not that there is anything wrong with the music ). Nicely done. And I like your monkey (ape).
> 
> Mark T


Hi Folks!
These are beautiful engines, the work in this thread is great to see.  BUT I'M GOING NUTS!!!  Watched the video at least three times, and never saw a monkey.  Must be a term I don't know or an inside joke.  Please help me scratch the itch in my brain that keeps going "What monkey...."
Thanks,
Stan


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## Geken (Apr 28, 2022)

stanstocker said:


> Hi Folks!
> These are beautiful engines, the work in this thread is great to see.  BUT I'M GOING NUTS!!!  Watched the video at least three times, and never saw a monkey.  Must be a term I don't know or an inside joke.  Please help me scratch the itch in my brain that keeps going "What monkey...."
> Thanks,
> Stan


Hi Stan. The monkey is my profile picture on Youtube
Geoff


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## stanstocker (Apr 28, 2022)

Geken said:


> Hi Stan. The monkey is my profile picture on Youtube
> Geoff


Ah...  Thank you kindly!  I was so focused on the video I completely missed it   Tree, I'd like you to meet forest...

Take care,
Stan


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## dnalot (Apr 28, 2022)

stanstocker said:


> Ah... Thank you kindly! I was so focused on the video I completely missed it




Mark T


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## GreenTwin (May 1, 2022)

LOL, I missed the gorilla.
.


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## dnalot (Jul 15, 2022)

Spring is not a good time to start a build. I have been keeping busy cleaning up after winter and enjoying some leisure time outside. I have 5 acres with lots of trees and it takes awhile to clean up. I live in a tiny town called Mossyrock. Its named that because everything gets covered with moss here. What time I have been in my shop has gone to annual machine maintenance. And continuing experimentation and perfecting my investment casting equipment and skills. Summer is now here and I hope to get a little more time in the shop.

I have now advanced to expecting good results rather than hoping for the best when casting. The parts that gave me the most trouble were the heads. Size was the issue. They are 3.6” in diameter. The main problem is that the pattern expands when heated before it turns to a gas during the burnout. That results in cracks in the plaster. Making the pattern a bit large and putting a radius on sharp edges helped a lot. And upgrading to a plaster made for use with resin patterns helped as well. Up to this point I have been getting away with plaster made for casting with wax patterns. The other problem was clearance between the side of the flask and the pattern. .25” is good. I had only .125” on both sides if centered. I had a couple of tries where the pattern touched the side and very bad things happened. I had to use a 4” flask as the 5” flask I ordered has been on back order for some time now.

The cylinder assembly now has its mounts and the exhaust manifold  installed. The valve surfaces have been polished. And the holes for the studs that will hold the steam chests have been drilled and tapped. 2-56 screws

The heads were giving me problems in printing. The resin is very brittle and required very heavy supports yet still tended to be ripped apart during the printing. I finally got a few decent prints and tried to cast them. I got the plaster cracking under control but kept having surface issues in the area near where the  sprue attached. I finally accepted the fact the heads would not be perfect and used the best two. The heads have now been machined to fit and drilled. And the ends of the cylinders have been drilled and tapped.























This last photo is of the plan set. 294 pages of drawings and illustrations. Mr Carlstedt did a fantastic job. But I may have found an omission or I might simply be blind. As I look forward to what to do next I have been looking at the drain valves. Several of them connect to what looks like a three way valve(2ea)  just under the steam  chest covers. I have not been able to find drawings for these valves. Help Richard Help.

Mark T

Thanks for watching and weighing in.


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## Richard Carlstedt (Jul 15, 2022)

Mark , did you download all the drawings ? my recall is that there are 309 pages in the book
The very last pages are the cocks , but you are right that I did not draw up the Tri-Cock itself
which I think you are referring to --- and which is the white arrow in the picture.
The red arrow is the cutoff chest drain.
The black and yellow arrows point to where drain cocks are  installed. They intersect the steam passages in the cylinder , and direct steam when turned on to the Tri-Cock . I'll  post a picture of their location if thats what you need. The cylinder drain cocks (4) were on the bottom of the cylinder and
I did not draw up the linkage which i know they used , but no details were found in my research
and that linkage may have been destroyed during recovery or lost due to corrosion.
Fabulous work Mark !
Rich


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## Richard Hed (Jul 15, 2022)

dnalot said:


> Spring is not a good time to start a build. I have been keeping busy cleaning up after winter and enjoying some leisure time outside. I have 5 acres with lots of trees and it takes awhile to clean up. I live in a tiny town called Mossyrock. Its named that because everything gets covered with moss here. What time I have been in my shop has gone to annual machine maintenance. And continuing experimentation and perfecting my investment casting equipment and skills. Summer is now here and I hope to get a little more time in the shop.
> 
> I have now advanced to expecting good results rather than hoping for the best when casting. The parts that gave me the most trouble were the heads. Size was the issue. They are 3.6” in diameter. The main problem is that the pattern expands when heated before it turns to a gas during the burnout. That results in cracks in the plaster. Making the pattern a bit large and putting a radius on sharp edges helped a lot. And upgrading to a plaster made for use with resin patterns helped as well. Up to this point I have been getting away with plaster made for casting with wax patterns. The other problem was clearance between the side of the flask and the pattern. .25” is good. I had only .125” on both sides if centered. I had a couple of tries where the pattern touched the side and very bad things happened. I had to use a 4” flask as the 5” flask I ordered has been on back order for some time now.
> 
> ...


I've been wondering how you were coming along with this build.  I would like to drop by, but I'm working and won't be able to find the time, until the season is over at least.  I can hardly wait for you to finish and show us it running


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## dnalot (Jul 16, 2022)

Richard Hed said:


> I would like to drop by


As you know you are always welcome Richard. 

Mark T


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## dnalot (Jul 16, 2022)

Richard Carlstedt said:


> I did not draw up the Tri-Cock itself
> which I think you are referring to --- and which is the white arrow in the picture.


It is. I will just wing it. 

Mark T


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## minh-thanh (Jul 16, 2022)

dnalot said:


> View attachment 138488
> View attachment 138489
> View attachment 138490
> View attachment 138491
> ...



It's really awesome !


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## minh-thanh (Jul 16, 2022)

Hi dnalot !



dnalot said:


> Just a quick post. The base for the steam chest has been glued to the cylinder and all went well. Tested for leaks and all is tight.
> 
> Mounted the cylinder to  the mill and trued up the valve surfaces and then relieved the flanges to locate the steam chest in place. All the steam chest parts now stack up properly and are located (locked) in position for drilling and tapping the holes for the bolts that will hold everything together. I will wait for a new 2-56 tap and the appropriate drill bits before I move on with this step.
> 
> ...



I have a few questions :
  What glue do you use ? Is it durable ? and why don't you solder ?


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## dnalot (Jul 16, 2022)

minh-thanh said:


> What glue do you use ? Is it durable ? and why don't you solder ?


Well it is not something I would normally do but I like to experiment sometimes. The epoxy is called JB Weld. In the way I used it I expect good results. Solder would have been better but holding so many pieces in place would have been difficult and I did not want to risk warping the cylinder material.  

I am a fan of yours Minh-Thanh. Love your builds.

Mark T


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## Robert Ritchie (Jul 18, 2022)

Nice pics,great work ,great description of work!  I'm anxious to see it run, job well done, so much work and effort but project is A1!


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## dnalot (Aug 9, 2022)

I have been working on the Bed-plate. The original was made of cast iron and was cast one-piece (I think) . Mine is made of aluminum and is assembled from 6 pieces. I cut the main parts with my cnc router table. The parts were then bonded together with JB Weld epoxy. After assembly smaller details were added and fillets were added where appropriate to mimic the look of the original's casting. I have no idea what color the original part was painted so I will go with something I like. For now the bed-plate has been etched with Alodine and painted with zinc chromate primer. I have provided a drawing of what this part should have looked like. Dam Murphy and his Law. I could have not mentioned the error and no one would have noticed except  Mr Carlstedt. But I didn't want to put him in the position of having to decide whether to mention such a huge mistake.









Part after being etched with Alodine. A must if you want your paint to stick to aluminum.














I am now working on the main shaft bearing support and the bearings for the rock shafts.

Mark T


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## Basil (Aug 9, 2022)

Very nice work. Had to look Mossyrock up. I lived in Castle Rock for many years before coming back to the UK where I grew up. Beautiful area! Looking forward to seeing this engine progress.


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## Robert Ritchie (Aug 11, 2022)

Oh so nice,great job Mark!


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## kvom (Aug 12, 2022)

Did you get the plans from Rich?  His "build book" is impressively large.


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## creast (Aug 12, 2022)

Impressive work Mark!


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## dnalot (Aug 12, 2022)

kvom said:


> Did you get the plans from Rich? His "build book" is impressively large.



Find the excellent drawings by R. W. Carlstedt here https://homeshopmachinist.net/resources/downloads/

Rich has been very helpful. Giving pointers on how he did some things and providing information about what the Museum that has the original engine has found during the conservancy.

Thanks for the likes and comments guys. Nice to know someone is watching.

Mark T


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## Dynamite-ralph (Aug 13, 2022)

I'm in the "Study the plans" phase now. R. W. Carlstedt did an excellent job with these plans.


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## dnalot (Sep 1, 2022)

I decided to paint the Bedplate olive-drab

The bracket for the crankshaft and thrust bearing has been added to the Bedplate. And the brackets for the translators have been added to the bedplate.

Bearing blocks have now been installed to the Bedplate assembly for the main  crankshaft, rocker shafts, translators and the shaft the  eccentrics will ride on.

I don't know what I will do next, now that I have options. With the big stationary parts made its time to start  adding the moving parts. I think the logical next step is to make some sort of mount and display stand. Mr Carlstedt mounted his model on a section of the hulls bulkheads. My model is of a larger scale and I don't want the size of the completed model getting out of hand so I will be doing something different.

Mark T


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## Robert Ritchie (Sep 9, 2022)

You've been busy, looking great, wow details really stand out, great job Mark!


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## dnalot (Sep 14, 2022)

I wasn't planning on returning to my shop till the fall but heavy smoke from nearby forest fires have driven me indoors. Expecting temps in the mid 90s so I can test the shops heat pump I repaired a few days ago while I'm here. I never normally use the AC function of my heat-pump but with the windows closed against the smoke its a must.

I have mounted the engine to a 14 inch diameter disk made or black walnut and mahogany. Wipe on Poly for a finish. The signboard is made of spalded hickory.  Later I would like to set this on a motorized turntable.

Power has been out this morning so I had to move outside to take this photo.


Mark T


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## GreenTwin (Sep 14, 2022)

Original engine design by John Ericsson, 1862.

Nice looking engine !

.


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## Steamchick (Sep 15, 2022)

Hi Mark, thanks for posting this one - VERY IMPRESSIVE WORK!
I am in awe of your efforts.
K2


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## Robert Ritchie (Sep 16, 2022)

Absolutely beautiful!  Icing on the motor,  finishing touches all perfect!  You did an remarkable job on this extremly difficult project, congradulations are in order!


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## dnalot (Sep 19, 2022)

Say hello to Andy  Beaverhausen. He is dressed in a sailor costume of the era. Just to lend some idea of scale. I don't know if I should paint him or just leave him as is.

Mark T






Pages 4 and 5 are just a lot of chatering, skip to near the end of page 6 to resume the build.

Thats what happens when you take to long between posts.

Mark T


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## GreenTwin (Sep 19, 2022)

The John Ericsson designed Monitor ironclad engine (1862) has fascinated me ever since I saw a video of Rich Carlstedt's build many years ago.
There have been others that built Monitor models, and one is in the Mariner's Museum in Newport News, Virginia, as shown in the video below.



Another build is from a source that unfortunately I did not save or document, and so I can't credit the source, but it was found somewhere online while searching for Monitor engine information.
These photos are not mine.
Perhaps the photo below is the same engine as shown in the video above?
They do look to be identical except in color, which may be just a function of the lighting when the photo was taken.










I think what distinguishes Rich's model from all the rest is the extraordinary attention to detail, not to mention the world-class machining work in a very small scale.

And Rich has worked with the museum that has actually acquired the original Monitor engine from the seabed, and I think Rich's understanding of the workings of this engine is better/deeper than the museum folks.

After documenting his Monitor build so accurately, Rich has become the defacto Monitor engine expert (and expert builder), in my opinion.

We shouldn't forget the original genius behind the design though, which is Swedish John Ericsson, not to diminish the work of subsequent model builders in any way.
What a fantastic set of patterns and molds that must have been, and no doubt it took a clever foundry person to cast that original engine.

I had the honor of seeing Rich's engine in person, and I can attest that it is as impressive in person as it is in the video, if not more so.
And I have heard a number of Rich's stories of his trials and tribulations of building such a complex and rare engine (a book in and of itself).
Rich has documented the Monitor engine in 2D and 3D, and this represents many many years of work, that he has shared for free.
Rich's work and his "gold standard" model have really peaked the interest in this fabulous and incredibly historic old marine engine.

And while reasearching the Monitor engine, I ran across a print of another John Ericsson engine that was built for the Monadnoch, which at the time was one of the few online sources for the working geometry for this engine.

Here is the Monadnock engraving.







This was a simulation I made using the geometry from the Monadnock print.
I drew a 2D CAD drawing, and rotated the parts a few degrees at a time, taking a GIF each time, and then combined all the GIF's to make an animation.
This was the first time I really started to undertand the geometry of Monitor-style engines.





Your browser is not able to display this video.






Edit:
Some (not sure how many) of the existing original Monitor drawings have been published, and I have seen a few of these.
I am not sure if John Ericsson himself created these drawings, or someone else, but they are certainly worth a look.
The quality of the original drawings is not very good, but luckily these drawings exist at all, since many/most drawings for old steam engines do not survive.

I have seen the original drawings for the Mississippi gunboat, and those drawings were created by Charles Copeland, who also designed the side lever engines for the same boat.
And Charles Copeland designed the side lever engines for the Pacific too, which is a most impressive steam ship.

Finding original drawings for these early 1800's ships is facinating, even if the drawing quality leaves a bit to be desired, since it gives us the original souce material for the design, and thus ensures that a very accurate model can be constructed (if you have that sort of talent).

.


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## Steamchick (Sep 20, 2022)

Well done Green Twin on the research. 
Bell cranks are simple devices to translate angular motion in one form to angular motion in another. e.g. where one lever in the middle of a hatch is used to drive a number of latches around the hatch. 
The sleeve to wrist-pin is a common design in many double acting Naval marine engines of the period, used for compactness. I think Brunel even used it on some of his engines?
The use of cranks to translate motion from one axis to another is very common in many industries where linear motion (e.g. from a piston) needs to be translated to some remote actuator.... e.g. vacuum or air pistons driving levers to operate brakes on railway wagons.
So the "simple" idea of combining all these attributes into a single engine is the clever bit. 
Walschearts valve gear is perhaps a super clever bit of crank motion design, as he uses various angles of crank to take the prime mover motion to create non-linear valve motion best suited to engine needs.
When I joined an electrical switchgear manufacturer in the 1980s, they had used bell cranks extensively to convert horizontal linear motion to vertical motion and back to the horizontal, always with 90degree cranks, but usually with different lengths of crank to gain velocity ratio or mechanical advantage. 
I had a problem of extending the contact breaker stroke, from the same actuator stroke by increasing crank lengths. But the electrical designer had set certain distances of travel of the contacts to occur at certain times (for the circuit breaker to extinguish the electric arc). To achieve certain speeds of contact at these points in the motion curve I used non-linear curves of velocity ratio and mechanical advantage - by simply rotating the cranks away from the "90degree" angle of 1:1 ratio of motion. This enabled the driving piston to do more work initially through a larger velocity ratio: more piston stoke than a 1:1 ratio would deliver (work = pressure x area x STROKE), thus accelerating the actuator to higher speed before "position 1" design parameter. As most of the "power" was lost during the mid-part of the motion, the remaining 20% of kinetic energy at the end of stroke could be transferred back from the actuator to power piston end of stroke so the whole system could be "stopped" by the high mechanical advantage of the end of stroke, without exceeding maximum stresses and strains of the components. - Not clever, just borrowing ideas from the centuries of "crank work" that had gone before. But it has left me fascinated by "crank-work" since then. - Maybe it has made me the "crank" that I am? Perhaps the cleverest original cranky idea was taking the simple beam of "linear to linear" motion (Early use of beams in atmospheric pumping engines, or village water pumps!) and making it into James Watt's "linear to rotational" motion of his patented crank beam engine design?
Then another curious "cranky" idea is the use of 2 valve gear motions from eccentrics being conjugated to a third motion for the 3rd cylinder of some Gresley steam locos...?





						LNER Encyclopedia: Gresley's Conjugated Valve Gear
					

Describes Gresley's famous conjugated valve gear as used used on the middle cylinder of his three cylinder locomotives.



					www.lner.info
				








Enjoy these cranky designs!

K2


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## GreenTwin (Sep 20, 2022)

The original Monitor drawings apparently show more than one engine configuration?, with one configuration having vertical cylinders (if I am looking at that drawing correctly).
I guess it is understandable that steam engine design of the era was in a state of flux, and there was no concensus about exactly what the best engine design/layout was.
Some of the Monitor's dimensions were driven by the very low profile of the Monitor hull, and the need to keep the engine below the deck of the boat.
The quality of the original Monitor drawings is much better than the quality of the original Mississippi gunboat drawings by Charles Copeland.

I would guess that Rich Carlsedt has compared the original Monitor engine drawings to the actual recovered Monitor engine, and he would have a better idea on the actual "as-built" design of the Monitor engine, as far as how closely the drawings were adhered to.


.


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## Richard Hed (Sep 20, 2022)

GreenTwin said:


> The original Monitor drawings apparently show more than one engine configuration?, with one configuration having vertical cylinders (if I am looking at that drawing correctly).
> I guess it is understandable that steam engine design of the era was in a state of flux, and there was no concensus about exactly what the best engine design/layout was.
> Some of the Monitor's dimensions were driven by the very low profile of the Monitor hull, and the need to keep the engine below the deck of the boat.
> The quality of the original Monitor drawings is much better than the quality of the original Mississippi gunboat drawings by Charles Copeland.
> ...


You are saying that there are original drawings somewhere?  I thot they were destroyed or bug eaten or something.


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## GreenTwin (Sep 20, 2022)

Rich Carlsedt will have to weigh in on the original drawings, because I am not sure how complete they are, and I see different variations for the engine.

But I have a set of (some?) of the original drawings for the Monitor engine, and they are pretty good drawings in my opinion, even if a bit light in contrast/visibility.

Unfortunately I don't recall the source for the original drawings unfortunately, but I have a digital copy of them.
The source may be the museum that is restoring the original recovered Monitor engine?

Rich knows all these things; perhaps he will fill us in.

.


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## kvom (Sep 20, 2022)

Interesting to see the cutaway view.  I'd always assumed there was one piston and a single rod.  So it appears that each piston only sees stem from the outer side to push it towards the center, and that it's retracted by the external crank.


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## dnalot (Sep 20, 2022)

kvom said:


> So it appears that each piston only sees stem from the outer side to push it towards the center


The two pistons have steam pressure applied to both sides

Mark T


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## GreenTwin (Sep 20, 2022)

Yes, it is two pistons, both double-acting.
There is I think a cylinder head bolted in place in the center, or perhaps cast in place.

It is quite a tricky little design.
I think it falls into the trunk-engine category?
Rich is the one who can answer all these questions.
He knows this engine like the back of his hand.

.


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## dnalot (Sep 20, 2022)

GreenTwin said:


> It is quite a tricky little design.


The tricky part is the steam chest valves. There are 2 in each chest. One works like what you find in most steam engines. The second is timed to take pressure off the first valve when it is in motion. Saving that for last.

Mark T


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## dnalot (Sep 20, 2022)

Richard Hed said:


> You are saying that there are original drawings somewhere? I thot they were destroyed or bug eaten or something.


I think they were found recently at Mar A-Lago

Mark T


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## Richard Hed (Sep 20, 2022)

dnalot said:


> I think they were found recently at Mar A-Lago
> 
> Mark T


Are they available to download?


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## GreenTwin (Sep 20, 2022)

dnalot said:


> The tricky part is the steam chest valves. There are 2 in each chest. One works like what you find in most steam engines. The second is timed to take pressure off the first valve when it is in motion. Saving that for last.
> 
> Mark T


I think the correct term is riding cutoff, when you have one valve riding on top of another.

Early cutoff gives far more efficiency of operation over just a standard D-valve, which is limited in how quickly it can cut off the steam after the start of admission.

The idea is to admit steam into the cylinder at or near TDC, and then cut off the steam at some point early in the piston stroke, and thus use the energy available in the expanding steam, as opposed to cutting off the steam late in the stroke.

A late cutoff produces a lot of torque, but is wasteful of energy.
Most steam locomotives had adjustable valve gear, so that when trying to get a train moving initially, the gear could be adjusted for a very late cutoff at or near the end of the stroke, and then once the train was moving, the gear adjusted to give a much earlier cutoff, since maximum torque is not needed when the train is moving.

.


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## GreenTwin (Sep 20, 2022)

I downloaded Rich Carlstedt's drawings a while back, and at a quick glance, they appear to be very high quality, like everything Rich does.
The Monitor engine is so complex that I have not had time to study Rich's drawings in detail.
I understand the Monitor's basic geometry and valve function, but that is the limit of my understanding of the many parts and pieces.
I do understand how trunk engines operate, in general.

Rich posted a link to some (all?) of the original Monitor drawings from the 1800's and I have downloaded quite a few of those.
I had to go back and find that link again tonight, since I had forgotten where it was.

I have not had time to research the original drawings either, to find out how complete they are, and compare then with Rich's drawings.
I suspect that Rich's drawings are very accurate, because that is how he works.

Here is the link to the original Monitor drawings.
A bit tedious to access and sort through, but thank goodness they have been digitized and posted.






						RUcore
					






					rucore.libraries.rutgers.edu
				





It is a bit of an art to interpret old drawings, and drawings in general.
I have gotten a lot of practice by working on a 3D model for the Mississippi side lever engine, from the original 1840 drawings.
The Mississippi original drawings are poor in quality, and contain errors, so that adds to the challenge.
Screencap of the Mississippi 3D model to date.
It is extremely tedious to 3D model an old engine accurately, and exactly as it was built originally.
There are so many subtle, tiny, but critical details in engine designs.
You basically have to start from the inside, and slowly work outwards, modeling one piece at a time, and making sure it mates correctly with any connecting parts.

As I undertand it, Rich Carlstedt has many years invested in his Monitor 3D model and associated 2D drawings, and I fully understand how long it takes to do that accurately.


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## Robert Ritchie (Sep 23, 2022)

Very interesting,  well written and explained clearly,  2d 3d cad drawing video great job! thank you for all the time and effort that went into this build and then sharing your talent with us, well done!


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## Richard Carlstedt (Sep 24, 2022)

Thanks to all for the kind comments
Green twin has been very accurate in his responses and you might say he has saved me many keystrokes  : )
Getting accurate information on the Monitor has now amounted to 30 years of research and
let me say, seeing a drawing does not make it right. I found large amounts of`incorrect`information both in written format or sketches and drawings. To separate the wheat from the chafe was a yeoman's job.  I am currently writing a book describing the engine (using My book of drawings for reference ) and will include the errors " I " believe that are prevalent.
The drawings that Green Twin mentions are available on the New Jersey Digital highway website, but be aware that of  the 80+ drawings posted , it is more than Monitor's engine. The engine drawings that are beneficial number perhaps 12-15 and most `are not dimensioned`.  One part on 3 separate drawings has 3 different lengths as an example of error. but I don't think it was error as much as being  the same part for different engines and the drawings were classified as a " Monitor" drawing
The engine should have been a 2 cylinder engine like the predecessors were, but Ericsson needed
to narrow down the engine's width because of the beam of the ship and used a common casting with a "center-head" separating the steam chambers . The valve chests ( 4) are a masterpiece of engineering, having the cutoff  valve in the outside chest and the main valve chest captured between the cylinder and cutoff and driven by 4 eccentrics with the control eccentrics ( F & R) being on the outside ( ! ) with Ericsson's  "Phase Changing " reversing gear.
My Original 2 D drawing ( AutoCad 95 ) was the size of a football field  as I drew the engine many many times in various configurations on the same field. ( 30-40 engines  plus many parts ?)
For example, I spent 6 months on one dimension alone, the C/L distance between the cutoff and main valve chest. It was either 10 1/4" or 10 " and I kept redrawing the engine to find what made all the parts fit. I settled on 10.25" 
The real KEY to solving the scale to use was the Navy overhaul report of Oct, 1862
where they recorded the size of the steam ports as 4" x 16" , and that alone was worth gold as
the general layout drawing of the engine had no dimensions. So the drawings that i got from a book were all measured with a 10 power pocket comparitor  and scaled to 5 decimal places.
in some cases I had to do a spreadsheet with what fits and what if's ...to get the dim.
I have to say, my Dims have held up quite well as they discover the real engine during restoration.
The highlight occurred maybe 10 years ago ( model was finished) and the museum showed me a "new" drawing they had just obtained from shipyard sources and it showed----10-1/4" valve rod spacing...and I smiled
The years of research required travel and there were only 4 Monitor models in existance to speak of before I built my replica.
The Smithsonian has Ericsson's 1858 patent model (no valve gear) (Not Monitor )
The British Science Museum (Kensington) had the actual Patent Model (1862) ( No Valve Gear )
New England model builder Ray HasBrouck  built a non scale model ( magnificent friend !)
Mariners Museum Builder Bernard Denny built a closer model from magazine info ( also Friend )
Ray and Bernie helped point me in the right direction even though they had no drawings as they had scratched built their engines . Bernnie's model is displayed at the museum  and both of Green twins pictures are of that model.
Hope this helps answer some questions.
Rich


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## Richard Carlstedt (Sep 24, 2022)

Here is an example of my work. I spent maybe  5-6  weeks on this drawing alone
and from that I will show you what that means
Now I only had a 5 x 7 book Zeroxed  print  to work with , but the Digital highway shows it full size
and much greater detail   but look at it anyway

https://rucore.libraries.rutgers.edu/rutgers-lib/42264/PDF/1/play/

Now here is what I saw in that picture
and the second picture shows what it means
The Purple images are added to the information derived from the above drawing
 As an explanation "Why" was this drawing made this way.. it is simple. the Civil War
 was going on and paper was being put to maximum use  and it was also some
" engineering concepts" being drawn --Ericsson's sketchpad so to speak

Rich








You can see my notes to myself in the last picture at the bottom
I had so much data on that football field drawing that I wrote notes all over the place to keep track of info . The above two pictures  were small images on that drawing

The two circles represent the Quadrant gear and the pinion gear ( 2:1 ratio) in the first drawing and then shown in purple
Rich


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## Steamchick (Sep 25, 2022)

Hi Rich. It seems that you have done an enormous amount of work deriving the history of this (Unique?) and historic engine. Trunk engines were relatively common at the time - or so I understand? (British naval use, Brunel and others had them?) but the head-to-head configuration - with bell-cranks to shafts to conrods to the drive shaft is a variation that is rarely seen, I think? (Necessary for "packaging" in the Monitor!).
And I didn't know about the special valve gear before reading this thread. - I must read more...
THANKYOU!
K2


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## GreenTwin (Sep 25, 2022)

I finally got around to unzipping all of Rich's drawings, and merging them into one PDF file.
Mother of gosh, that is a lot of drawings !!!!

What a phenomenal amount of work that went into that 3D model and 2D drawing set.
I would classifiy that as a "ludicrous" amount of effort, and I am shocked that anyone could pull that off.

Some comparisions beween the 3D model I am making for the Mississippi side lever engine and the Monitor engine:

1. The Mississippi engine was designed and built around 1840.
It looks like there were some pretty dramatic advances in steam engine design from 1840 to 1861.

2. The Mississippi engine is a big sprawling Cornish-style (check me on that) engine, and luckily there are quite a few examples on paper and physically available for study.
Compared to the Mississippi engine, the Monitor engine is very small and very compact, with a tremendous amount of complexity compressed into a very small area.
The gigantic size of most of the Mississippi engine parts, and generous spacing, makes it seem infinitely easier to 3D model than what I would imagine a 3D model of the Monitor would entail.

3. The Mississippi engine drawings are very poor, and apparently this was Charles Copeland's first attempt at a steam engine design, because there are some real gaffs in his drawings.  I did find a set of drawings for an 1840 French-designed side lever marine engine (very close in design to Copeland's Mississippi engine), and the contrast between the French drawings and Copeland's drawings is like night and day.  The French drawings were obviously designed by a very seasoned professional engineer and professional drafting person, and they are excellent drawings even by today's standards.

4. I typically model engines that don't have very many parts, and generally one cylinder designs.
The reson for this is practical, given the time it takes to create an accurate 3D model, and also to align my building skills with model complexity.

Rich is on a phenomenal building skill level, and all I can say is his skills are shocking.

I have had the pleasure of speaking with Rich on two occasions, and I recall discussing what it takes to build a Monitor like Rich's.
I told Rich "It is the persistance".
Rich said "What about the skill?".
I said "Well, yes, that too, but many folks who had the required skill level may not persist through such a build".
A person has to have the skills, drive, determination, and persistance to carry on when the build is going well, and more importantly carry on when the build is not going well.

It is one thing to build a model engine, and a whole different thing to create an enormous accurate drawing set for the Monitor.
The combination of engine build and accurate drawings is so over the top of anything I have seen that I really don't know how to give it justice.

And not to forget this is "Mark's Monitor" thread, what a superb job Mark is doing with this very complex engine.
I have done quite a bit of casting work, and Mark's castings look so very nice.
I can appreciate how difficult it is to make such nice castings.

I am in awe of this build thread, and everyone who is involved with it; that is all I can say.

.


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## johnmcc69 (Sep 25, 2022)

Nice work Mark! I love the finish!

 Keep on going with it!

 John


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## Richard Carlstedt (Sep 25, 2022)

Steamchick said:


> Hi Rich. It seems that you have done an enormous amount of work deriving the history of this (Unique?) and historic engine. Trunk engines were relatively common at the time - or so I understand? (British naval use, Brunel and others had them?) but the head-to-head configuration - with bell-cranks to shafts to conrods to the drive shaft is a variation that is rarely seen, I think? (Necessary for "packaging" in the Monitor!).
> And I didn't know about the special valve gear before reading this thread. - I must read more...
> THANKYOU!
> K2


Yes, It is a rare engine of sorts (for a trunk) and unique and I cannot find any other engines built like Ericsson's  design- It is actually a "Half Trunk" since it is only on one side of the piston and is unlike many other half trunks, which are usually oscillating engines. Monitor was the first* Vibrating Lever Half Trunk*  engine ( 40 x 22 Bore/Stroke) , and  they built 10 more slightly  modified and then went to 48 x 24 for another nine engines so a total of 20 engines were built to that design.  Unfortunately some folks refer to the Monitor engine as a 'Side lever engine" which is completely incorrect. Look at Green Twins Drawing in post 70 for what is a side lever engine design. World of difference !
I am very pleased that outstanding models of Ericsson's design have been made by both builders Geoff and Mark.
They truly reflect the complicated construction and operation of this engine and committed to the details to show that ...Bravo !
Rich


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## Richard Hed (Sep 25, 2022)

Does anyone know if John Ericsson wrote anything about his engines and work?


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## GreenTwin (Sep 25, 2022)

The book that Rich refers to "Drawings of the U.S.S. Monitor" by Earnest Peterkin has an extensive list of drawings that have been found in various places for the Monitor.

It appears that Ericsson envisioned a prototype called a "Sub Aquatic Weapon" in 1826, which he tried to market to several countries.
I aways suspected that while the Monitor may have been constructed in 90 days (so they say), the design of this gunboat materialized over many years, and was refined as time progressed.

Each drawing has a brief description of where the author thinks the drawing originated, and who he thought drew it.

The book describes how Ericsson requested that upon his death, all of his papers should be destroyed.
I assume this means he wanted the Monitor drawings destroyed too, but I am not positive.
Luckily someone rescued Ericsson's papers after his death, so they were not destroyed.

There were some in the Navy that harshly criticized Ericsson, and did not consider his boat/ship designs up to navy standards.
Others noted that the Monitor hull was not watertight, and so the concerns did play out, and the Monitor sank, I think during a storm while being towed in the ocean.

Given the demanding circumstances of the time, I think the extremely fast construction of the Monitor, and its ultimate function in battle were significant.  There is much debate about who won the Monitor/Virginia battle.  It is often decribed as a draw, but it did appear to stop the Virginia from inflicting further damage to the Union wood ships.

The drawings in Peterkin's book appear to be monochrome, but some of the original Monitor drawings I downloaded from the Rutger's Library (link above) are in color, which is really cool to see, and are works of art in my opinion.

Peterkin's book contains some coorespondence between some Navy folks and Ericsson, concerning things such as how stable the Monitor was, etc.
Apparently there was concern about the weight of the turret, but Ericsson proved that the Monitor stability was more than adequate even with the massive turret sitting on top.

I also read a book about the actual battle, and I forget the title, but is a fascinating story for sure.
As I recall, the captain of the Monitor was in the forward lookout position, and it took a direct hit, blinding him, but not killing him.
I thought my job was tough.

Another fellow inside the turret was injured when a shell/cannon ball struck the turret, as this fellow was leaning against the metal armor.
I guess the shock wave or the deflection of the metal was sufficient for injury of anyone toughing the turret.
The men inside of the turret that were not touching the sides were not injured.

You can download a PDF copy of the book "Drawings of the U.S.S. Monitor" by Earnest Peterkin at this link:









						Drawings of the U.S.S. Monitor : a catalog and technical analysis : Peterkin, Ernest W : Free Download, Borrow, and Streaming : Internet Archive
					

Prepared for the Division of Archives and History, Department of Cultural Resources, State of North Carolina. Sponsored by the Sanctuary Programs Division,...



					archive.org
				




I suspect that John Ericsson must have written about his work, or at least we can learn a lot from his coorespondence with many people.

There is so much history wrapped up in this engine and boat, both from a technical standpoint, and from the standpoint of the human side of the navy men that operated it.

Edit:
I think the book above also mentions that Ericsson already had a patent for an engine design that is very similar to what was used in the Monitor.
This reinforces the idea that the Monitor boat and engine were the result of many years of Ericsson designing and refining both.
I am not sure how they could make patterns, cast the engine parts, and machine the engine parts in 90 days, much less install all of the equipment in the boat, but that is the story that is told (not sure I believe the 90 day thing, but I suppose it could be possible).

.


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## Richard Carlstedt (Sep 26, 2022)

Richard Hed said:


> Does anyone know if John Ericsson wrote anything about his engines and work?


Yes Richard there is a book.  you can find the digital version here








						Contributions to the Centennial Exhibition : Ericsson, John, 1803-1889 : Free Download, Borrow, and Streaming : Internet Archive
					

The Commissioners of the Centennial Exhibition having omitted to invite me to exhibit the results of my labors connected with mechanics and physics ... I have...



					archive.org
				



It is sort of a autobiography of his accomplishments
I have a thousand comments about John Ericsson but am tied up  now, so will respond more 
comprehensively in a short time 
Rich


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## Richard Carlstedt (Sep 26, 2022)

The Centennial Exhibition was about the accomplishments of the USA in the first hundred years ( thus 1776-1876) and was a massive display of technological developments . They painted a portrait 
of  about 56 (!) Inventors -living and dead- who made America great and they did not include john Ericsson and he got mad and wrote a book about his accomplishments , which is the one noted in my last post. Well the Exhibition  commission realized they had made a mistake and added John to the painting. but this was just some of the negative feelings about John and they were embarrassed by his call-out. If you read the book, you will be amazed at his talent.
Besides building the Monitor which is said to have 40 inventions alone  , he built the first steam powered Fire Engine, He invented the Screw Propeller used on every ship and boat today, he invented powered torpedo's and he started the Solar Energy capture by building a Solar powered motor that took sunlight and turned it directly into mechanical rotary motion  and this was in 1870 ! His calculations of Solar power can still be used today.  Don't forget, the Monitor was the first modern warship- all iron- engine power below waterline -rotating Turret- and stealth design .
More later
Rich


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## KellisRJ (Sep 27, 2022)

GreenTwin said:


>


FWIW, I do recall reading that to speed up the build, many items were subcontracted. Not the norm where in a single shop or facility, a knowledgeable person would be available to give a hole dimension.  Without giving a factual reason, the author reported serious troubles when a component would arrive and a hole was the wrong size. I figured without a good dimension, the subcontractor simply used what made sense to them.
Ron


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## GreenTwin (Sep 28, 2022)

Many of the original Monitor drawings I have seen were dimensioned, but it must be kept in mind that some of the Monitor drawings that exist today were created as the Monitor was being built, or even after the Monitor was built (according to one of the books Rich mentions above).

Back in the day, when I started school, there were no personal computers, no CAD; we had punch cards and FORTRAN on an IBM mainframe (don't underestimate FORTRAN, it took us to the moon).   We hand drew everything using either ink, or more often pencil, and vellum.  Vellum is a cotton-based paper that is very durable (like the material that money is printed on).

We used engineering and architectural scales, originally made of wood, and later of plastic.
Even if our drawings were not dimensioned, typically they were drawn to some scale, and I suspect the same holds for the Monitor drawings.
The folks building the Monitor and using a drawing that was not dimensioned would still be able to use a scale to read the dimensions of the various parts, as long as the scale of the drawing was known.

You can generally figure out the scale of a drawing pretty quickly if you don't know what it is, but not always.
One of the most costly mistakes you can make is to issue a sheet with the wrong scale on it.
When I print my sheets these days, I still lay a physical scale on some known dimension, just to be sure the drawing was plotted at the right scale factor.

If you ever had to produce manual drawings for a living, you really appreciate excellent draftsmanship when you see it.
The original multi-color Monitor drawings are just plain artwork, as well as some very creative engineering.
The only other color drawings I recall were for the Brooklyn Bridge project, and those too are works of art.

Rich's drawings are first rate too, with some stunning 3D color isometric views, and I am very glad I did not have to make those drawings, given how complex they are, and the enormous quantity of drawings involved.

Edit:
One thing to remember with old drawings is that the lines are generally first laid out with dividers, and the sharp points of the dividers actually punch holes in the vellum.  If you ever seen the faint outline of pinholes in drawings, those are the reference points you should use for things like the centerpoint of circles, etc.

I think it was said that a good draftsman could control a drawing down to about 1/64", but check me on that.
When I am creating CAD drawings or 3D models of engines using photos only, I round the dimensions for each part to something usable; otherwise you end up with a lot of odd measurements such as 1.2157385". (round it to 1.2", or perhaps 1.22", but you get the idea).
I also have a standard bolt/screw chart, and select the bolt or screw that is closest to what I am seeing/measuring.

I read a Scientific American article about the ancient Greek/Roman temples, and it noted that no drawings had ever been found for those structures.  Then a guy noticed some faint lines on the stonework of a temple that was destroyed by an earthquake before it was completed, and he discovered that the plans were etched lightly into the temple walls and floor.  When the temples were completed, the walls were polished, removing all evidence of the drawings.  The ancients did have exact drawings for temples, and they are illustrated in the Scientific American article.  The columns were drawing foreshortened, perhaps 6 feet tall, and the compressed vertical scale makes them look like a beer barrel.
The builder took off the column width dimensions with dividers at the appropriate vertically scaled increments, and transferred that to the actual very tall column.  This is a very clever way to avoid having a 50 foot tall (or more) drawing.

.


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## GreenTwin (Sep 28, 2022)

KellisRJ said:


> FWIW, I do recall reading that to speed up the build, many items were subcontracted. Not the norm where in a single shop or facility, a knowledgeable person would be available to give a hole dimension.  Without giving a factual reason, the author reported serious troubles when a component would arrive and a hole was the wrong size. I figured without a good dimension, the subcontractor simply used what made sense to them.
> Ron


And I don't think there were standard fastener/thread sizes when the Monitor was built, but I could be wrong.
It makes me wonder if the Monitor fasteners were interchangeable, or if each one was custom-cut/filed, such that a nut would only screw onto its mated bolt.

.


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## Richard Hed (Sep 28, 2022)

GreenTwin said:


> And I don't think there were standard fastener/thread sizes when the Monitor was built, but I could be wrong.
> It makes me wonder if the Monitor fasteners were interchangeable, or if each one was custom-cut/filed, such that a nut would only screw onto its mated bolt.
> 
> .


Ah.  I've wondered about when they started making standard nuts and bolts too.  We take them for granted but at the beginning of the technological (industrial) revolution, nuts and bolts were made one by one and matched as you all know already, but when did the standardization begin?  It seems that someone clever would have made a fortune making standardized nuts and bolts and absolutely NOTHING else!  They could have had two dedicated lathes and kept the machines running day and night just making nuts and bolts.  How many nuts and bolts are made today in a year?  Billions.


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## GreenTwin (Sep 28, 2022)

Charles Porter talks about the period of time when the standard twist drill bit was not common, in his book "Engineering Reminiscences" talks about when he first discovered some manufacturers using twist drills. (Charles Porter created the first high speed stationary steam engine).









						Engineering reminiscences contributed to "Power" and "American machinist" : Porter, Charles T. (Charles Talbot), 1826-1910 : Free Download, Borrow, and Streaming : Internet Archive
					

xiii, 335 p. 24 cm



					archive.org
				




From page 30 and 31:

_In preparing for the establishment of the governor manufacture I visited the works of Geo. S. Lincoln & Co., in Hartford, and saw twist -drills in use, cutting chips instead of scraping. They attracted my attention and I inquired about them, and was told that they made them themselves. They kindly took me into the smith-shop and had one made for me to witness the operation. The smith heated a round bar of steel and swaged channels in it on opposite sides. They had quite a set of top and bottom swages for different-sized channels. He then took another heat on the bar and twisted it by hand, giving a gradually increasing twist, which at the end was quite rapid.

An increasing twist was obtained in this way. The drill was held in a vise, so that only the projecting end of it could receive the amount of twist then being imparted. The drill had to be moved in the vise of course a number of times. The channels were smoothed out with files, and when the drill was turned in the lathe sharp cutting edges were developed, which needed only to be backed off by grinding.
I took one of these drills home with me to serve as a pattern and equipped my shop with them. They were of the highest use to me. The small ones drilled the holes for the governor joints, and the large ones drilled the counterpoise and the column for the governor spindle. I suppose the twist-drill had its origin in these Hartford works._

_I never saw any twist-drills in England except at Mr. Whitworth's, and these I thought were the funniest things I ever did see. They were twisted by the blacksmith out of square bars and with a uniform quick twist, were left rough, and did not fill the hole, and the ends were flattened out in the form of the common drill to scrape, and not to cut.
When I returned from England in 1868 twist-drills were coming into general use in this country.  After 1876 the firm of Smith & Coventry introduced them in England._

_At that time almost everything in machine-shops was done in the old-fashioned way, and accuracy depended entirely on the skill of the workman. The tool work left much to be done by the fitter. 
Interchangeability was unknown, even in screw-threads. For example, when nuts were removed from a cylinder head, pains had always to be taken that each nut was replaced on its own bolt, as no two were exactly of a size. This condition developed a class of very skillful all-round workmen; but my earliest observation showed me that in manufacturing it was important that so far as possible the personal factor should be eliminated.

I adopted the rule that in mechanical work there was only one way to insure that anything should always be done right, and that was to make it impossible that it should be done wrong. For example, in my governor gears their true running required that the bore should be absolutely correct, both in position and in direction. I had seen many gears bored. They were held in the jaws of a chuck and trued by marking their projecting side when running with a piece of chalk. It was evident that absolute truth could hardly ever be reached in this way, and the approximation to it depended wholly on the skill and pains of the workman.

._


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## KellisRJ (Sep 28, 2022)

GreenTwin said:


> And I don't think there were standard fastener/thread sizes when the Monitor was built, but I could be wrong.
> It makes me wonder if the Monitor fasteners were interchangeable, or if each one was custom-cut/filed, such that a nut would only screw onto its mated bolt.
> 
> .


The Brits were the first with Whitworth 1841. US had some, a document was published in 1864. Civil War rifles had interchangeable parts, as did standard Quartermaster mule wagons. But IIRC it wasn't until 1916,  WWII and the introduction of Johansson Blocks that standardization really hit the US. The now standard reference Machinery Handbook was first published in 1914 with several standards, but SAE wasn't there yet. Wikipedia, and an interesting book "One Good Turn: A Natural History of the Screwdriver and the Screw"


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## Richard Carlstedt (Sep 29, 2022)

I have done a study of bolts in connection with my Monitor research. Unfortunately the real
expert I found ( Mel Kirsner)  has passed on and his Museum burned down years ago.
Standard Nut Donates Items to Museum  | Global Fastener News.  He called it  "Mell's Nut house"
You have to be careful when you talk about threads !
Whitworth started the standard with THREAD FORM  (55 degrees)in England  and the Franklin Institute ( Philadelphia)  in 1864 set the USA form at 60 degrees, but `the threads per inch and bolt` size were not standardized (in the USA) until about 1906  (ANSI) and have progressed from there .
Mel told me that Maudsley invented the Hex Nut Milling Machine in 1829  which allowed nuts to be made and the first _commercial Nuts _sold in a US Catalog was from a new England source in 1854.
The impetus for standardization was driven by the Carriage/Wagon trade  as manufacturers of tooling or in the case on Monitor, made there own nuts and bolts to their own standards . For example, I have a 1890 B & S Dividing head and it has 1/4-22 screws .   WW 1  brought great demand for standards, but it seems that the Automobile Industry was the real driver after that. 

A little trip back in time  !
Don't forget that many shops made their own tools.
You had "machinists" working in machine shops but the best machinist , or I should say the most skilled man worked in the ........Tool Room .  There, he was known as "the Tool Maker" or a 
"Tool and Die Maker" as he made tools for the shop to use. He made drills,taps,cutters and Dies and special tools.  He was special , but the world has changed as most of the stuff is now commercially available 
 It is sort of funny to me to hear about lathes being described as "Tool Room Lathes" and folks have a mis-under-standing what a Tool Room Lathe is ?
In the old days , A (real)  Tool Room lathe was very precision for making tools and had a unique threading ability and arrangement where the feed would drop out ( Single dog clutch-No threading indicator needed )  and then re-engage in perfect timing and at high speeds needed for quickly making threads.- remember, these guys made taps and dies  !  I believe only Hardinge makes such a lathe today

In my Drawing book for the Monitor, I only specified diameters of bolts, except where a few threads were called out on those early drawings
Rich


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## Steamchick (Sep 29, 2022)

Another boring bit from me...?
On history of toolmaking: I am descended from a family called "Filer" - because he made files. 
Imagine a blacksmith who made seriously good wrought steel, before manufacturing mass production of steel was developed. The steel was used for swords, knives, tools for woodworking, and for graving metal (Not just engraving, but for using hand tools to machine softer metals in simple lathes, based on wood working expertise).  In flintlock strikers you needed a small piece of hard, rough, sharp, abrasive steel to make the flint "spark". 





						flintlock steel - Bing images
					






					www.bing.com
				



The first files being the abrasive plate installed in a flintlock (never seen one - just what I was told) had to be very fine. The modern equivalent is the abrasive steel wheel of a sparking lighter that uses a flint. A piece of grind-stone in a flint-lock mechanism was prone to falling out, but the "new steel" files were fixed in place and didn't fall out when the metal was hot from use and expanded.
- I was taught the flintlock promoted the original design of files - single cut, not like modern cross-cut files. The teeth were cut by a cold chisel, very hard and sharp, held at an angle to create the sharp edge of the teeth. A single strike per tooth. Try it, quite a difficult skill! The skill was in making the uniform spacing and close alignment of the teeth so the file action was smooth and it cut soft iron cleanly. 
Hand-held grind-stone tools were used to hand shape knife blades etc. But the guy who made good steel started making files, by cutting annealed steel bar with a chisel, then hardening and tempering the file - and was called "Filer". Instead of "Smith".  
 A "steel" was the name given to a very fine file used for sharpening knives (and swords) - like a chef uses. (Or did before H n S changed the design!). sharpening steel for knives - Search
Carrying fine grind stones for sharpening the plough or sword was not so easy, as they broke when struck or dropped. A steel was a more durable sharpener... But you can still buy them for sickle and scyth sharpening.





						scythe sharpening stone - Search
					






					www.bing.com
				




Many blacksmiths made wrought steel for tips for ploughs, etc. as they wore much less than the softer iron shoe that turned the soil. - Hence, when war developed (e.g. Charles Cromwell's mob etc.) they turned Ploughshares to swords" - and back again after they returned from war. 
One reason that old battlefields rarely have deposits of swords, knives and other weapons, etc, is not just that they have rusted away, but were spirited away immediately afterwards by the camp followers as useful steel for everyone afterwards!
Move on to later tool and manufacturing processes: (MY distorted memories from tales told by the machinist when I was a lad in a workshop?). When they started making metal bicycles, they set the thread cutting lathes to 26threads per inch - to try to emulate a METRIC 1mm pitch that was developed as a common size in France...
Once set, they made all the bolts, of whatever diameter, in 26tpi. And Triumph motorcycles and others were doing this in the 1960s - until the "dammed infernal yanks" overwhelmed us with their machine tools in WW2 and we started using UNF, UNC, sizes in car manufacturing... displacing the historic quirks and idiosyncrasies we had held onto for so long in our beloved Great Britain. Of course, some threads in the transport industry, and in many other industries, they had used Whitworth and BSF for decades, and electrical people used BA... "because it suited them". Gas people used "pipe threads, brass component makers used their own brass threads, etc. But it was all the stuff from USA (that wasn't sunk by U-Boats) that changed the UK (to the 53rd state) to using UNC and UNF - until politics decided we should become "European", and thus converted us to "Metric" sizes.
I'll not rant about that one.
Enjoy! (And correct my errors for the record?)
K2


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## GreenTwin (Sep 29, 2022)

This particular topic was created by dnalot, but it is not a run of the mill model engine build, but rather a build of what is argueably the most historic marine engine every built, certain with respect to American history.

On top of that, Rich Carlsedt has spent many years documenting this historic engine, and he has uncovered a vast amount of technical information about it, and the methods used to build it, and dnalot is using those plans for this build.

There is no way to conveniently pigeonhole this build into a nice little simplistic model building thread.
This is a very significant engine, and it deserves significant discussion.  This engine cannot be trivialized.

The fact that dnalot (Mark) has gone to so much trouble to build a very accurate Monitor engine makes the peripheral discussions all the more important, especially with regards to those who may follow and want to build their own accurate models of this engine.

.


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## GreenTwin (Sep 29, 2022)

I have not heard Mark complain about this thread or its contents, and it is his thread as you say, so perhaps we should let him determine what information he wants to display here, and not try to tell him what his thread should look like or what comments it should or should not contain from other members.

I am hoping that he will post an update soon.

I am assuming that he is working like a beaver on his Monitor, and hope that all is going well.
This is such a complex undertaking, especially given the fact that he is making his own castings.

I have been following Mark's investment casting thread with great interest:






						Mark's First investment casting
					

Mark's Lost Resin Casting or Old fart learns new tricks.  I have been doing sand casting and lost foam casting for awhile and that works out well for larger parts. But for smaller parts lost wax or plastic works better. I could only do the sand casting when the weather permitted as it needed to...




					www.homemodelenginemachinist.com
				




and Mark's burnout kiln thread:






						Marks Kiln build
					

I am setting up a bench-top foundry in my shop for doing lost “resin/pla/wax” casting and I need a small kiln. I looked at commercially available units and found the prices quite sobering and then the shipping costs and for me (10.3  percent) sales tax. So I looked at home built units on...




					www.homemodelenginemachinist.com
				




This fellow has a lot going on, and the quality of his castings is most impressive.

.


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## GreenTwin (Sep 29, 2022)

There is a discussion on another thread about a governor, and it does not seem the Monitor had a governor, so it makes me wonder exactly how the Monitor engine was controlled.

I notice the bypass valves in the upper steam chests, so that the cutoff valves can be bypassed.
So is it safe to assume the main Monitor valves were designed for a late cutoff?

And there is a throttle valve on the Monitor, in the main steam line.
So is that really a throttling valve, or just a cutoff valve?
I would assume it is really used for throttling, since it is a rather elaborate valve design.

I would really like to hear what Rich knows about how the Monitor engine was operated.

My guess is that the boat speed was controlled by the throttling valve, and the cutoff valves were simply used to produce the same amount of power and torque, but using a greatly reduced amount of steam (ie: use the expansive power of steam, and an early cutoff).

I would also guess that during fighting maneuvers, the bypass cocks were open, thus giving the engine maximum torque regardless of efficiency.
Who cares about efficiency when cannon balls are flying?

Edit:
I am going to have to look at Rich's drawings again.
The crank handle and gear mechanism was used to reverse the engine? but I was thinking this mechanism controlled the cutoff valves.
Now I am wondering how the cutoff valves were adjusted.
.


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## Richard Carlstedt (Sep 29, 2022)

No governor used on Monitor, the 9 foot propeller kept the RPM's down , really the engine room staff were the governors 
The Grate Valve in the main steam line was the Throttle Valve for the engine.  Coal was a very expensive  fuel and conservation of fuel was paramount to marine operations, particularly if you operated in unfriendly waters. The engine ran on 30 PSI steam and when in cutoff mode made 60 RPM which produced  6 Knots on the 980 ton ship. Full speed, without cutoff ,was 80 RPM and resulted in 8 knots of speed. At that point , the boilers were maxed out as the ship had other steam engines running pumps and blowers ( Hull was pressurized to facilitate boiler draft and prevent asphyxiation ) Ericsson testified  that the engine could run 100 RPM  if the other steam engines were silenced , but of course  that could only be for a very short time. The engine was rated at 350 to 425 HP depending on the information source .
Yes, in battle the Cutoff valves would be bypassed to give full power to the engine . By the way because of the close proximity of the boiler to the engine, engine room crew worked in 135 degree (F) temperatures and served only 1/2  hour at their post except during battle . Amazing  !
if you look at the engine , there is three gauges , with the engine "register" on the left. It recorded
the "turns" ( revolutions) of the engine . The center gauge is steam pressure and the far right is a clock with a sweep second hand and the Captain would holler the number of turns he wanted in a tube to the engine room and the chief engineer would count the turns made in one minute as he adjusted the throttle. the grate valve was very effective as a steam control device
Rich


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## Richard Hed (Sep 29, 2022)

Steamchick said:


> Another boring bit from me...?
> On history of toolmaking: I am descended from a family called "Filer" - because he made files.
> Imagine a blacksmith who made seriously good wrought steel, before manufacturing mass production of steel was developed. The steel was used for swords, knives, tools for woodworking, and for graving metal (Not just engraving, but for using hand tools to machine softer metals in simple lathes, based on wood working expertise).  In flintlock strikers you needed a small piece of hard, rough, sharp, abrasive steel to make the flint "spark".
> 
> ...


Charles Cromwell?  You mean The Lord Protector?  The one who cut off the head of king charles I?  Oliver Cromwell?


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## GreenTwin (Sep 29, 2022)

Thanks Rich for the fascinating information.

I thank my lucky stars every day I did not have to work in that engine room.
I have worked as an operator of a large sawdust-fired boiler, but it was in a large well ventilated room, but still a bit hot.

I am studying your video now, and looking at what happens to the valve gear as you rotate the valvegear actuator.
Starting at 1:00.



What I am seeing is the eccentrics for the cutoff valves and the eccentrics for the main valves shifting as a unit, together.
And so what this tells me is that there is no adjustment for the cutoff valves, and no adjustment for the main valves either.
Is this true?  There was no way to adjust the cutoff?

It would make sense that if you change the phase of the main valves, the phase of the cutoff valves would have to follow proportionally.

.


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## Richard Carlstedt (Sep 29, 2022)

Yes, The Cutoff function was only used in forward motion. 
when the engine was reversed, the cutoff bypass valve would be opened and 
that effectively meant the cutoff eccentrics and cutoff valve were inoperative. 
So at the 1 minute mark, the main eccentrics are being rotated 180 degrees for reverse  and if you look at the cutoff valve rods right behind, you see no motion. The cutoff eccentrics are fastened (keyed) to the reversing shaft, while the main valve eccentrics are really "slip eccentrics". 
You could adjust the main valves somewhat and give them "Lead" . The quadrant gears turned the main eccentric ( pinion) and stopped when the key was met/engaged with the pinion gear fastened to the main eccentrics.  ( see 1.00 to 1.20)  - 

Now "if" the quadrant gears  rotated the pinion , but stopped short of the key, the engine would reverse and run , but then had lead on the timing. Of course the penalty for doing that was the reversing shaft transmitted power to throwout bearing  which then passed it to the quadrant gears ,which then transmitted it to the Pinion gear fastened to the eccentric . That does work but involving the whole mechanism means excessive wear of all those components. Normally, the pahse changing mechanism has no load on any component during running operation, only during the actual changing of direction do they see load 
Hope this helps

Rich


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## terryd (Sep 29, 2022)

Richard Carlstedt said:


> I have done a study of bolts in connection with my Monitor research. Unfortunately the real
> expert I found ( Mel Kirsner)  has passed on and his Museum burned down years ago.
> Standard Nut Donates Items to Museum  | Global Fastener News.  He called it  "Mell's Nut house"
> You have to be careful when you talk about threads !
> ...


Hi,
I don't know if you have identified your B & S dividing head screws but if not I would check the thread angle as that dia x pitch is a British Standard Fine (BSF) combination using a Whitworth thread form.

Regards
TerryD


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## terryd (Sep 30, 2022)

Steamchick said:


> ................. But it was all the stuff from USA (that wasn't sunk by U-Boats) that changed the UK (to the 53rd state) to using UNC and UNF - until politics decided we should become "European", and thus converted us to "Metric" sizes.
> I'll not rant about that one.
> Enjoy! (And correct my errors for the record?)
> K2


Hi K2,
It wasn't politics that decided to change to the SI metric system (defined by the ISO of which GB is a participating member) from the imperial, it was economics we didn't become 'European' we became 'International'.  Most of the rest of the world had been metricated quite quickly and certainly by the mid 20th C. the SI units were standardised especially in the scientific community, after all there are now only 3 countries still using derivations of the 'English' system officially and the USA is in good company with such influential industrial countries as Myanmar (Burma for Imperial supporters) and Liberia.  Although units based on the Imperial system (The US system is the 'customary' system and differs from the imperial in some units) are still in limited, vernacular use in many others, mostly ex Empire countries where British systems were imposed on the locals.  It was realised that the UK would lose out on international trade if we stuck to an outmoded system so capitalism won, alongside science and technology.

The UK government first discussed the prospect of adopting the metric system in 1818 - most scientists and engineers agreed.  The metric system, based on units of 10 was first proposed by several English scientists and engineers during the 18th C. (e.g. John Wilkins suggested it in 1790 and Gunter's chain, still used by some surveyors and cricket lovers, has 100 links as part of the move to decimalisation) but the idea was taken up by France as their measurements were in chaos, (as was most of the rest of the Worlds at that time), each region and sometimes towns had their own definitions of the so called 'Standards'.

The systems on which the 'Imperial' system was based was basically European developed from earlier units such as the 'cubit' and 'hand' by the Greeks and Romans essentially and used parts of the body as the basis for linear measures.  Unfortunately not everyone has the same sized bodies and very different definitions of, for example, feet and inches existed, weights were based on the natural world on such things as the carob seed and barleycorn and multiples thereof and the sexagesimal system for time was defined by the Babylonians. It's interesting to note that the Imperial system of measures was not finally defined until 1824 while the French had defined the basic metric system in the 1790s (although Napoleon later reverted to the traditional names for measures) based on previous suggestions from among others British scientists and engineers.  By the way the 'Standard' Kilogramme of 1790 was made of platinum cast by Johnson Matthey in England.

Familiarity with a particular system, be it Tte Imperial, the Winchester or the US customary doesn't make it any better it is standardisation that matters and the SI system with it's well defined basic units from which all others are derived won out.

Best regards

TerryD


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## terryd (Sep 30, 2022)

GreenTwin said:


> Many of the original Monitor drawings I have seen were dimensioned, but it must be kept in mind that some of the Monitor drawings that exist today were created as the Monitor was being built, or even after the Monitor was built (according to one of the books Rich mentions above).
> 
> Back in the day, when I started school, there were no personal computers, no CAD; we had punch cards and FORTRAN on an IBM mainframe (don't underestimate FORTRAN, it took us to the moon).   We hand drew everything using either ink, or more often pencil, and vellum.  Vellum is a cotton-based paper that is very durable (like the material that money is printed on)............
> 
> .


Hi,

As a point of interest, vellum is actually made from animal skins aka 'parchment' but vellum was distinguished by being made from calf skin which made a superior product and has been in use since ancient times, I think it may have been the Babylonians in Mesopotamia (now iraq) where it was first used. They also made a writing medium from the local 'papyrus' reed leaves woven and then beaten into thin sheets hence the name 'paper'.

I started my drafting career in the early 60s in the UK engineering industry and generally we drew on paper using pencil, which made it easy to rectify mistakes, then the important ones (drawings not mistakes!), once okayed by the Chief Draftsman were transferred onto drafting film, which is similar to what you refer to as vellum, by tracing using ink pens by 'tracers' usually women.  That film was made from cotton fabric stiffened with starch and was more or less transparent.  (If you managed to get hold of a length the starch could be washed out and the cotton sheet was great for pressing the crease into formal trousers).  Cotton based 'paper' is indeed very smooth and was referred to by manufacturers as 'vellum' to infer a higher quality product, smooth and consistent like the original material it superseded in everyday usage. These master traces, being transparent were used to make working copies of the drawings on the large printing machines for use on the shop floor.

Vellum (the animal skin) was used for important and permanent documents in ancient times and for books such as those beautiful illustrated Bibles in the medieval period among other uses, even now it is used for important ceremonial documents, at least here in the UK.

TerryD


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## Steamchick (Sep 30, 2022)

Richard Hed said:


> Charles Cromwell?  You mean The Lord Protector?  The one who cut off the head of king charles I?  Oliver Cromwell?


Thanks Richard, Of course you are right. That is an example of how my brain jumps out of mesh sometimes... and why I don't trust my own writings... 
Sorry if this discussion of the history of technology around the time leading up to the monitor has detracted from some peoples' enjoyment of the thread. 
K2


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## GreenTwin (Sep 30, 2022)

Richard Carlstedt said:


> Yes, The Cutoff function was only used in forward motion.
> when the engine was reversed, the cutoff bypass valve would be opened and
> that effectively meant the cutoff eccentrics and cutoff valve were inoperative.
> So at the 1 minute mark, the main eccentrics are being rotated 180 degrees for reverse  and if you look at the cutoff valve rods right behind, you see no motion. The cutoff eccentrics are fastened (keyed) to the reversing shaft, while the main valve eccentrics are really "slip eccentrics".
> ...


Well that clears it up........NOT !
Its not that Rich didn't explain it, it is that my limited brainpower is having a lot of trouble seeing it in a comprehensive fashion.
This is not a simple valve gear mechanism/engine operation, in my opinion.

I will start a new thread about my general approach to understanding valve gear, so as to not clutter up this thread.







						Valve Gear Design for Steam Engines - My approach
					

I became interested in steam engines at a young age, as I assume as many folks did, by operating a Wilesco steam plant and engine, which was a single-action oscillating engine.  I went so far as to build a boiler and single-acting steam engine for a 12 grade science project. Most folks who saw...




					www.homemodelenginemachinist.com
				





.


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## terryd (Sep 30, 2022)

KellisRJ said:


> The Brits were the first with Whitworth 1841. US had some, a document was published in 1864. Civil War rifles had interchangeable parts, as did standard Quartermaster mule wagons. But IIRC it wasn't until 1916,  WWII and the introduction of Johansson Blocks that standardization really hit the US. The now standard reference Machinery Handbook was first published in 1914 with several standards, but SAE wasn't there yet. Wikipedia, and an interesting book "One Good Turn: A Natural History of the Screwdriver and the Screw"


Hi Kellis,

I agree about the book, entertaining, educational, fascinating and very readable.  Worth getting access to a copy (library? in the UK a library can accesss interlibrary loans to get books from any other library around the country on loan, not sure about the US.)









TerryD


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## GreenTwin (Sep 30, 2022)

So if I understand the Monitor valve gear correctly, the main eccentrics can be moved to a forward or reverse position, or perhaps a position to give a little lead in forward.

The cutoff eccentrics are fixed to the shaft, and they are not adjustable, at least not dynamically as the engine is running.

I guess I am a bit surprised that there is not a dynamic adjustment on the cutoff valves.
Is this because some optimum point for cutoff was found at which to run the engine while in forward motion?
I guess if the limiting factor was the boiler capacity, then perhaps not much need to vary things other than with the throttling valve.

Maybe no adjustable cutoff because the load on the propeller was constant?

On some steam engines, it seems that full pressure is always applied to the steam chest, and in some cases the speed/power of the engine regulated by dynamically adjusting the throw of the valves, thus eliminating the need for a throttling valve.

I am puzzled by the fixed cutoff.

.


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## Richard Carlstedt (Sep 30, 2022)

OK, Lets talk about cutoffs.
 There are several types (3 ? ) , there is a Riding Cutoff where the Cutoff valve _*directly *_rides on top of the main valve. This type generally allows various _*amounts*_  of steam admission  and in some cases has a governor controlling the steam feed .This is a variable cutoff setup.
Then there is a cutoff that has a valve working in it's own chest ( AKA Cutoff chest)  , and this is what Monitor has . This type can be* variable *or *fixed*.
 The variable can be controlled by a governor, or by moving the eccentric locations .
The Fixed have a preset /predetermined cutoff point that was based on design expectations.
 In the Monitor's case, John Ericsson determined that if steam was cutoff when the stroke
had reached  40%  of travel that it would propel the ship at his cruise speed ( 6 Knots) and require less coal. The Cutoff Eccentrics were fastened ( fixed with a key) to the main shaft unlike the Main Eccenttrics which could be rotated on the shaft for direction control
. My guess is that it would only use half the steam required versus full power, of course there were other engines running for air and water pumps  so maybe 75 % Boiler use (?)
Rich


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## Richard Carlstedt (Sep 30, 2022)

You can see the chests in Marks post # 5

The main steam valve rides on the valve face of the Cylinder ( 3 port slots shown) and that is in his first picture
Then in the Second picture you can see the Main Steam Chest  that covers the main valve  and
its top has 2 slots for the Cutoff valve , and then the Cutoff Valve Chest is a cover and has the barrel inlets for steam 

Rich


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## GreenTwin (Oct 1, 2022)

So I guess the variable cutoff was either the bypass cocks open, and a late cutoff via the main valves, or the bypass cocks closed, and a much more economical early (fixed) cutoff.  I guess two options then.

And I assume there was probably a "sweet spot" or optimized point for the cutoff valve setting, that used the best compromise between boat speed, power produced, and steam efficiency; given the fixed boiler output available.

Very fascinating valve gear for sure.
Thanks for all of your info Rich.
I have problems understanding it even when looking at Rich's very elaborate drawings and exploded views.
It amazes me that anyone has figured out exactly how this valve gear worked.

And very cool that Mark is attempting this build, with so much success.
Hats off to anyone who even attempts this engine.

.


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## kvom (Oct 1, 2022)

The ship was likely not intended to steam in reverse for very long, so cutoff was deemed unnecessary.


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## dnalot (Oct 15, 2022)

As the weather cools I am starting to work in my shop again. This post will cover the crankshaft. Probably the easiest crankshaft I have made. I used leaded steel for the parts made from round stock so I elected to “blue” the steel to help with corrosion. As an extra barrier I coated the steel with a light oil with a drop of lanolin. I made the crankshaft a bit shorter than the real deal to better fit on my display stand. The shaft to web is keyed and is a hard press fit. The crank pin has no key but is also a hard press fit.

Mark T


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## Richard Hed (Oct 15, 2022)

I love this work.  HOpe to see it.  I have 12 days left of regular work then some part time till probably early Decemember.  Would like to come by to visit your lathe and other tools.


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## dnalot (Oct 15, 2022)

Richard Hed said:


> Would like to come by to visit your lathe and other tools.


Always welcome. FYI, you will be getting a pat-down before you go. 

Mark T


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## Richard Hed (Oct 15, 2022)

dnalot said:


> Always welcome. FYI, you will be getting a pat-down before you go.
> 
> Mark T


LOL


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## johnmcc69 (Oct 17, 2022)

Really nice work Mark! Great fit & finish.

 John


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## dnalot (Nov 5, 2022)

Thanks for the comments and likes guys. FYI this thread has had over 11000 views so someone is interested. I took most of the summer off and a great summer it was, not a drop of rain for three months. And then 12 days ago it started to rain. And it never quit raining, I had 3.5" of rain yesterday. So I will be picking up the pace on  this build as winter sets in.

So here we have the connecting rods. Fiddly little parts. Took way longer than I expected to make. My desktop mill struggles when cutting steel.  Next up the rocker shafts.


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## Richard Hed (Nov 5, 2022)

Steamchik:
(e.g. Charles Cromwell's mob etc.) they turned Ploughshares to swords" - and back again after they returned from war.

did you ever read an unprejudiced book abouit Cromwell?  I'm surprized to see you on the naughty side of the question.  I understands it is more of a fighting question (like our own civil war), in Britannia than here.  HOwever, I am a proponent of Cromwell--naught that he didn't have his serious problems, I mean, Newton was on the other side mostly because Cromwell was anti-science.  But the Charles's were worse IMNSHO.  During the first CW, Cromwell won and basically gave back the crown to Charles I who then went and started his dirty trix up again.  That's why he got his hed chopt.


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## dnalot (Nov 5, 2022)

Stay on subject please

Mark T


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## Steamchick (Nov 6, 2022)

Sorry Mark.


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## dnalot (Nov 25, 2022)

Here are the rocker shafts. Beefy bits these are. Bet it took a fair sized work crew to move these into place. I have them nicely fitted to the bearings and they turn smoothly. They were made of two parts and silver brazed together. The big hole through the arm is an artifact from the previous use of this bit of metal. I plugged it with a steel plug pressed into the hole and sand blasted the part except for the bearing surfaces. I used leaded steel that rusts quickly so I blackened the part to help with corrosion.

Next up will be the arm that connects the con-rod to the rocker shaft.

Thanks for watching

Mark T


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## Steamchick (Nov 26, 2022)

Mark, I love the care and attention you apply to every part. Really a top example of how to make and finish a model - as you progress. Wish I had the patience, knowledge, time, etc. to follow your example. I must try harder!
K2


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## Richard Hed (Nov 26, 2022)

Do you know how they assembled the engine inside the Monitor?  You said it weighed 30 tons.  I can imagine it did.  So each of those parts you have shown us would have weighed 7-800 lbs?   I can just imagine men trying to man-handle the parts thru a hatch too narrow to get the part easily down.  They must have put the engine in before putting on the deck.  did they have more than one deck?


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## dnalot (Nov 26, 2022)

Richard Hed said:


> Do you know how they assembled the engine inside the Monitor?  You said it weighed 30 tons.  I can imagine it did.  So each of those parts you have shown us would have weighed 7-800 lbs?   I can just imagine men trying to man-handle the parts thru a hatch too narrow to get the part easily down.  They must have put the engine in before putting on the deck.  did they have more than one deck?


I believe the deck was made of wood covered over with iron plates. So I would think they assembled the engine in place and decked over it. I was a boat builder by trade and that is what we would do. Often I would make the cabin top removable for changing out an engine. A sleeved engine could generally be rebuilt in place, only requiring the cabin floor to be removed.

Mark T


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## Richard Carlstedt (Nov 26, 2022)

Richard, They built/assembled the engine in a 6-7 week time period from what I can find and then installed it in the partially built hull on December 16, 1861 and the top deck with turret and cannons installed in the following 6 weeks before launching at the end of January 1862

Rich


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## Steamchick (Nov 27, 2022)

Hi Richard, Sailors have always managed large loads, (Anchors, cannon, cannonballs, rocks for ballast, etc.) by the use of ropes and pulleys from shear legs or cranes from above. (Many ships had masts that hauled very large loads, but the Monitor in dock would have had an overhead crane for this task). A cylinder weighing 1/2 ton would not be a problem, but a 30ton engine was probably assembled in the hull from suitable sized sub-assemblies, perhaps even before the side frames and sheeting were built-up. (As per Brunel's ships of that era?). 


			https://vanda-production-assets.s3.amazonaws.com/2018/01/12/14/12/08/9303f1b0-7d48-45e1-b7de-e75a55d525d6/2006BH5367-Great-Eastern.jpg
		

Titanic had the ships keel and bottom frames built, then the engine mounting frames were fitted, and a huge milling machine (Sold 15+ years ago by Harland and Wolf to Korea for around £2m... on E&@y!) finished the final machining so the bed was flat before the engines were assembled on top.
K2


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## Dana_T (Dec 27, 2022)

Hello everyone, I am Mark T's sister Dana. I am so sorry to have to tell you my brother Mark passed away on December 20th. He was 72 years old. On Thanksgiving day he enjoyed a wonderful meal and he was looking good, but a couple days later he began to feel sick. His wife took him to emergency where they determined he was having a major heart attack. After a few days in the hospital it looked like he was going to make it and making slow progress,  but then things started to go the other way. After  three weeks in the hospital Mark passed away quietly and peacefully. Mark loved his shop, his projects, his family, this forum and the people in it, the deer that bedded down in his yard and just maybe most of all his cats of which he had many over the years. Reading through this project thread of Mark's I was at once happy to see how much he was enjoying this project and sad that he was not able to complete it. I'm not sure what else needs to be said, but if you have questions I'll check in here tomorrow and answer what I can.

Dana T.


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## GreenTwin (Dec 27, 2022)

This is terrible news indeed.
So sorry to hear this.

It was obvious from following this thread that Mark had immense talent.

No doubt his family is dealing with a huge loss at this point.

It was an honor to watch Mark's work progress.
Very inspirational stuff for sure.

Thoughts and prayers to all of you.


.


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## Richard Hed (Dec 27, 2022)

My friend Mark?  How could he?  He certainly did not look to be 72--maybe in his 60s.  I visited him twice in Mossy Rock and got to see his incredibly interesting models.  He told me he had some health problems and so he was careful what he did.  I was planning to visit again, maybe in the spring time.  He was a heck of a nice guy.  I hope his wife can handle it, I'm sure she was somewhat prepared.

Very sorry to hear of his passing.


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## Richard Hed (Dec 27, 2022)

Dana_T said:


> Hello everyone, I am Mark T's sister Dana. I am so sorry to have to tell you my brother Mark passed away on December 20th. He was 72 years old. On Thanksgiving day he enjoyed a wonderful meal and he was looking good, but a couple days later he began to feel sick. His wife took him to emergency where they determined he was having a major heart attack. After a few days in the hospital it looked like he was going to make it and making slow progress,  but then things started to go the other way. After  three weeks in the hospital Mark passed away quietly and peacefully. Mark loved his shop, his projects, his family, this forum and the people in it, the deer that bedded down in his yard and just maybe most of all his cats of which he had many over the years. Reading through this project thread of Mark's I was at once happy to see how much he was enjoying this project and sad that he was not able to complete it. I'm not sure what else needs to be said, but if you have questions I'll check in here tomorrow and answer what I can.
> 
> Dana T.


Dana, I am really sorry to hear this.  Did you ever see that prize-winable photo he had of the wild cat?  It was a fabulous photo.  He photographed a lot of wild life (I thimpfk) from his livingroom window.
Don


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## minh-thanh (Dec 27, 2022)

Dana T !
   So sorry to hear this.
From someone on the other side of the earth .
 Projects that MarK has built on are mechanical works of art, I've always loved the engines he's built. All engines he did are a source of motivation and inspiration for me and others
    Dead are never dead to us, until we have forgotten them 
  Mark and his projects will live forever !


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## Steamchick (Dec 27, 2022)

Thanks Dana,
A well respected modeller who gave many of us pleasure with his exquisite work. Sadly missed.
Ken


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## stragenmitsuko (Dec 27, 2022)

Oh dear . Sad news indeed .


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## davidyat (Dec 27, 2022)

*So sad. I was in awe of his work. I would just gawk and stare at his magnificent work, they were works of art.
Grasshopper*


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## Basil (Dec 27, 2022)

So very sorry to hear this. A truly talented man. My sincere condolences.


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## fltenwheeler (Dec 27, 2022)

Dana_T said:


> Hello everyone, I am Mark T's sister Dana. I am so sorry to have to tell you my brother Mark passed away on December 20th. He was 72 years old. On Thanksgiving day he enjoyed a wonderful meal and he was looking good, but a couple days later he began to feel sick. His wife took him to emergency where they determined he was having a major heart attack. After a few days in the hospital it looked like he was going to make it and making slow progress,  but then things started to go the other way. After  three weeks in the hospital Mark passed away quietly and peacefully. Mark loved his shop, his projects, his family, this forum and the people in it, the deer that bedded down in his yard and just maybe most of all his cats of which he had many over the years. Reading through this project thread of Mark's I was at once happy to see how much he was enjoying this project and sad that he was not able to complete it. I'm not sure what else needs to be said, but if you have questions I'll check in here tomorrow and answer what I can.
> 
> Dana T.


I am so saddened by your loss. 

Tim


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## Richard Carlstedt (Dec 27, 2022)

Dana, My sincerest sympathies to you and all of Mark's family . 
He was an exceptional man, and it is quite apparent he would follow his heart
and was unfazed when it came to new challenges . This is quite apparent with  
the many challenges he faced with this current project that he solved with exceptional skill
 I appreciate having conversed with him recently and this news is certainly a shock to me.
Thank You for letting us know, it shows Mark's personal communication concepts were also shared  in his family and are very gracious !

Rich


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## cd195 (Dec 27, 2022)

Dana_T said:


> Hello everyone, I am Mark T's sister Dana. I am so sorry to have to tell you my brother Mark passed away on December 20th. He was 72 years old. On Thanksgiving day he enjoyed a wonderful meal and he was looking good, but a couple days later he began to feel sick. His wife took him to emergency where they determined he was having a major heart attack. After a few days in the hospital it looked like he was going to make it and making slow progress,  but then things started to go the other way. After  three weeks in the hospital Mark passed away quietly and peacefully. Mark loved his shop, his projects, his family, this forum and the people in it, the deer that bedded down in his yard and just maybe most of all his cats of which he had many over the years. Reading through this project thread of Mark's I was at once happy to see how much he was enjoying this project and sad that he was not able to complete it. I'm not sure what else needs to be said, but if you have questions I'll check in here tomorrow and answer what I can.
> 
> Dana T.


So sorry to hear of Mark’s passing!  I liked his posts; he was a great asset to this forum, and will be greatly missed.
Carlos Diaz


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## oldCB (Dec 28, 2022)

Dana_T said:


> Hello everyone, I am Mark T's sister Dana. I am so sorry to have to tell you my brother Mark passed away on December 20th. He was 72 years old. On Thanksgiving day he enjoyed a wonderful meal and he was looking good, but a couple days later he began to feel sick. His wife took him to emergency where they determined he was having a major heart attack. After a few days in the hospital it looked like he was going to make it and making slow progress,  but then things started to go the other way. After  three weeks in the hospital Mark passed away quietly and peacefully. Mark loved his shop, his projects, his family, this forum and the people in it, the deer that bedded down in his yard and just maybe most of all his cats of which he had many over the years. Reading through this project thread of Mark's I was at once happy to see how much he was enjoying this project and sad that he was not able to complete it. I'm not sure what else needs to be said, but if you have questions I'll check in here tomorrow and answer what I can.
> 
> Dana T.


 So sorry to hear..condolences to your family.


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## Dana_T (Dec 30, 2022)

Thank you everyone.

At some point,  the family would like to find someone with the necessary skills and interest to take on completing this project. It meant so much to Mark and he had so much time and work put into it, it would be a shame to see it go uncompleted. I'm not sure how to go about finding the right person, but suggestions and recommendations can be sent to me via private message (please do not make suggestions here, it might be awkward). It is very important to us the project is completed with the same skills and commitment as Mark had to produce a quality model.


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## Dana_T (Jan 5, 2023)

Hello again everyone,

Well! I have some very exciting news to announce! With the help of Ron Kellis (KellisRJ) I have found someone to complete Mark's Monitor engine. Todd Cahill has very graciously agreed to take on the project. I believe most here are familiar with Todd's work, if not you can checkout his website here: ABOUT | steamachine. There's also YouTube videos highlighting Todd and his steam engines, and his wonderful drawings that can be seen on his website.



Todd will be starting a new thread for you to follow when he begins. That will likely be months from now as we need to figure out shipping from Seattle to Boston, and Todd is still in the process of relocating his shop. 

Dana T


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## minh-thanh (Jan 5, 2023)

Dana_T said:


> Todd will be starting a new thread for you to follow when he begins.
> 
> Dana T


 Why not this thread ??
this thread ....That would make more sense


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## Dana_T (Jan 5, 2023)

I didn't ask Todd why a new thread, perhaps he wasn't comfortable resuming this one. It is his project now, he has my full support and trust to proceed with the project, and to document his work here as he sees fit.


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## GreenTwin (Jan 6, 2023)

Todd Cahill seems like an excellent choice for someone to complete Mark's Monitor.

Todd appears to be deep into the style and class of the Monitor era engines, ie: 1840-1860's, so that will be very helpful.

It will be very exciting to see this engine move towards completion.
Mark worked far too hard on this engine to let it get stopped, and it is a superb lesson in lost wax castings.

Best of luck to everyone involved.
I will be following and supporting if necessary.

I will send Todd a note of support and encouragement via his website.






						ABOUT | steamachine
					






					www.steamachinesculpture.com
				





Pat J
.


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## ShopShoe (Jan 6, 2023)

I'm glad to see that the project will be continued. Thank You to all that were involved in making it possible.

--ShopShoe


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## Richard Carlstedt (Jan 6, 2023)

Yes, the dedication,skill and commitment that Mark made should not be for naught.
Cudo's to Dana and family for pursuing the project and completing Mark's work.
As we all know, this is seldom found in our hobby and is much appreciated by all, especially
with the skill level displayed by Mark.

Rich


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