Navy back to Sextant

[SmithDoor]

This off subject of engines.
Asking about Navy is teaching Celestial Navigation to new officers.
The Navy start this about 10 year ago with training new officers but making the news this year. I was read whole article but could not find it.

I hopping some one else read the article or better know why
Maybe have copy .

I think of a resion is solar flares.

Any know other reasons why you need Celestial Navigation today?


It could a interesting project is make sextant, Bubble octant, transit or Astrolabe.

Dave

FYI
1) Sextant for use in ocean
2) Bubble Octant. Aircraft in air
3) Transit. On the land
3) Astrolabe. Very old use on ocean similar to Bubble Octant

 

[ChazzC]

Haven’t seen the article you are looking for, but I learned celestial navigation when I was in NROTC training at college and was required to complete a “day’s work” in celestial navigation as part of my Surface Warfare Qualification after I was commissioned. At that time most ships had satellite navigation and we had a satellite communications system installed while I was Communications Officer (I was later Navigator, and we always took star and Sun sights every day as a backup to SatNav). I also learned the Morse Code, how to read signal flags and a lot of things you don’t have the clearance & need to know for me to discuss, but all of this was long ago.

Professional Officer Training has been very lax in the Navy during the last 10 - 20 years, which resulted in a number of collisions and deaths, with subsequent very senior officers being relieved and IIRC court martialed. I can only assume that the US Navy is attempting to get training reinstated and is starting from the ground up.

 

[kvom]

I took a class in Celestial Nav during a sailing trip from Bermuda to Fort Lauderdale. I bought a Russian sextant on eBay and still have it. Sun and moon sights were easy but I could never hold steady enough for stars.

You practice at home using a pan of motor oil as an artificial horizon.

 

[SmithDoor]

I took a class in Celestial Nav during a sailing trip from Bermuda to Fort Lauderdale. I bought a Russian sextant on eBay and still have it. Sun and moon sights were easy but I could never hold steady enough for stars.

You practice at home using a pan of motor oil as an artificial horizon.

( I could never hold steady enough for stars )
I think problem with most of us will have.

They Navy most hàve some reson for teaching navigation on Sextant.

After looking all different types it could a fun project to build too.
The Astrolabe. It is Very old use on ocean simple to use

You practice at home using a pan of motor oil as an artificial horizon

I was told a sextant is harder to on dry land. Pan motor sounds great.

(I know off subject of engines it just fun to look at)

***** Below is just accuracy data & information *****

I did transit but on ground not a rolling boat or ship.
The transit I have is 20 seconds that is within 2,000 feet

The Navy could train most officers on the open sea to be with 1.5 miles.

Navigates on large aircraft in WW2 said the hope to be in 25 miles on a moving aircraft.

Radio navigation (radio direction finding (RDF) ) is less than 1° accuracy .
{Basically the closed you are to transmitter the more accurate }


GPS is generally accurate to within 16 feet (5 meters) under open sky conditions


Base on Earth I use circumference 24,900 Earth is not round.

Dave

 

[clockworkcheval]

There is an easy rationale for sailors on the high sea to learn celestial navigation: if for any reason your electrical systems fail - batteries, engine, a short - you can still rely on your sails to get any place, as long as you know where you are and where to go.

 

[rleete]

They teach it for the same reason that engineers have to learn differential calculus. To teach that person how to learn. I can't think of a single instance where I used differentials in 35+ years of design engineering. But I do have critical thinking skills, which I never got in High School.

 

[ChazzC]

They teach it for the same reason that engineers have to learn differential calculus. To teach that person how to learn. I can't think of a single instance where I used differentials in 35+ years of design engineering. But I do have critical thinking skills, which I never got in High School.

Agrre

Traininglike celestial navigation also helps young officers better understand what the sailors who work under them do and the difficulties of the jobs. Morse & Signal Flags were practical since flashing light and other visual signaling is still used for "non-electronic" messaging.

 

[GreenTwin]

We had 4 semesters of calculus, the last one being differential equations.
Many people have asked me "Do you solve calculus equations in your everyday work?".
The answer is "No".

It should be understood though that calculus is the language that describes how things function in the world/universe.
Engineers don't know everything, and so you have large handbooks, and nowdays online reference material and white papers.

The handbooks and reference material speak in the language of calculus, and so if you look something up in order to verify how it operates, such as a synchronous motor, the equations used to describe starting, stopping, operation, and short circuit of that motor are written in calculus.

Calculus could be written out in words in english, but it would be very tedious to read and use.
A shorthand equation of a few symbols would end up being something written out such as "the rate of change of the field current is inversly proportional to the sine of the ......................"; this is a made up example, but you get the idea; you don't want to have to write it out longhand.

Calculus is the written language of engineering.
If you can't read and understand the meaning of calculus, then you are not going to be a competent engineer.
Same as the ability to read a book.
If you can't read written language, you will be very limited in what you can achieve in life.

While you many not sit around and solve engineering forumulas all day, an engineer definitely thinks in calculus; things like "this feedback is non-linear", or "the current decays depending on the rate of change of whatever", or "if this variable is not carefully controlled, the process will have an exponential runaway", etc.

It took me a long time to figure out what calculus was, and every class I took for four years was saturated in calculus.
Either you immerse yourself in the language, or you find another line of work.
For a while there in the beginning, I was not sure if I could get a handle on what it all meant.
The classes became more challenging with each year.
The controls class was one of the last ones I took in school, and it was the most interesting class I ever took.
If you understand how controls work, you can understand how many things work in fields way beyond just electrical circuits, such as how the human body works as far as inputs, outputs, dedicated brain functions, nervous system connections and feedback, electrical signals to control muscle movement, etc.

.

 

[HMEL]

This off subject of engines.
Asking about Navy is teaching Celestial Navigation to new officers.
The Navy start this about 10 year ago with training new officers but making the news this year. I was read whole article but could not find it.

I hopping some one else read the article or better know why
Maybe have copy .

I think of a resion is solar flares.

Any know other reasons why you need Celestial Navigation today?


It could a interesting project is make sextant, Bubble octant, transit or Astrolabe.

Dave

FYI
1) Sextant for use in ocean
2) Bubble Octant. Aircraft in air
3) Transit. On the land
3) Astrolabe. Very old use on ocean similar to Bubble Octant

One very good reason for teaching this is the vulnerability of our satellites in orbit. Its also a good discipline to understand the basic function of electronic navigation as they are based on the same principle. And for the record a sextant is a different instrument then a transit. The sextant requires a watch and star charts whereas a transit measures only angles and is a surveying instrument.

 

[SmithDoor]

There is an easy rationale for sailors on the high sea to learn celestial navigation: if for any reason your electrical systems fail - batteries, engine, a short - you can still rely on your sails to get any place, as long as you know where you are and where to go.

I whish that was in article on if everything broke down.

It is like some maybe super cargo ships having a engine and prop. What can go wrong . The bridge just jump out and hit the ship.

The last information I had the US Navy uses 2 or 4 engines/props They can steer the Ship with out a rudder or one engine and rudder.

Dave

 

[SmithDoor]

One very good reason for teaching this is the vulnerability of our satellites in orbit. Its also a good discipline to understand the basic function of electronic navigation as they are based on the same principle. And for the record a sextant is a different instrument then a transit. The sextant requires a watch and star charts whereas a transit measures only angles and is a surveying instrument.

The biggest between the Sextant and transit is the Sextant uses the ocean for leavel and transit need on stable ground.
The sextant also has filters for viewing the sun.

A good Transit is great viewing the stars it low power (mind is only 32X) but adjust easily. I do not think in today books on transit they talk about Celestial Navigates. Today's cellphone with GPS does better job.
The transit that is 20 seconds can find you are with 2,000 feet , GPS is 16 feet or even closer.

If you lost in desert 2,000 great. The GPS at 16 feet is great for driving.

The transit I have is also call a analog theodolite. I use for laying out large steel beams also for setting large machine tools.

Dave

 

[a41capt]

There is an easy rationale for sailors on the high sea to learn celestial navigation: if for any reason your electrical systems fail - batteries, engine, a short - you can still rely on your sails to get any place, as long as you know where you are and where to go.

I wonder if someone at the top is concerned about a virus impacting our satnav system in time of war…

 

[RM-MN]

I use a GPS guidance system to spray my fields. I don't have enough land to justify RTK but using GPS, Beidou, and Glonass I can guide my sprayer within less than 5'. If I were to spend the money to get RTK, I could be within 2 inches or less.

 

[RM-MN]

I wonder if someone at the top is concerned about a virus impacting our satnav system in time of war…

More likely enemy jamming the system. Russia and Ukraine both play this "game".

 

[SmithDoor]

They teach it for the same reason that engineers have to learn differential calculus. To teach that person how to learn. I can't think of a single instance where I used differentials in 35+ years of design engineering. But I do have critical thinking skills, which I never got in High School.

I agree
The big thing was teaching high school was how to use chart and tables for wood construction.
At time when High school and college i did iron work and welding. I could see how all work . It also helped my father did engineering on metal buildings too.
We also tried the transit on navigation. The only problem we had figuring out starts. I also Great-circle navigation on a slide rule.
E6B is great for dead reckoning too.
We did this all without a any electronics. Just paper pencil, slide rule, E6B. We talke about navigation on the B17 fighting 250 mph and how long took us. By time figure everything you would have gone 75 miles .
So need to do dead reckoning with E6B and paper to find where you are.

Dave

 

[SmithDoor]

Just think of sailing in 1492 use a Astrolabe Latitude only. With dead reckoning using a rope and hourglas/sandglass.

Longitude was in the 1700's with better time keeping

 

[SmithDoor]

Simple way of finding Longitude
Use sun dial to find the time where at only by sun
Use global with time disk on the top set to disk to watch/clock (note best Greenwich) . Now find the time off sundial on dial.
Now you have Longitude

See photo on the disk on top global.

Greenwich is zero time for almost everthing

Dave

 

[SmithDoor]

I wonder if someone at the top is concerned about a virus impacting our satnav system in time of war…

I wish I knew
Would satellite get virus?

If ship navigation equipment got virus some one could a cellphone.

I know one the Navy had a few tube radios just case transistor was burn up after a nuke when off.

I wish I had save to article from October. I could follow the links and find out more

Dave

 

[ChazzC]

The last information I had the US Navy uses 2 or 4 engines/props They can steer the Ship with out a rudder or one engine and rudder.

Dave

Large ships use multiple shafts to get the necessary Hp into the water, also for redundancy. Smaller and auxiliary ships typically have one.

Yes, with multiple shafts you can “steer” a ship without using the rudder, but it is not practical for anything other than limping around.