Incoming Hamilton Model 21 chronometer

Well been wanting one for years. Well I was searching Ebay I see one for the price I paid for model 22 years ago. So at halve the price they sell for I pull the trigger.





What's a plus is the repair receipt so you know what ship it came off of any ships timepiece in my collection I don't know what ship it came off of. I know it's not off a military ship but merchant marine did serve in WW2. Did ask the seller to cork the balance wheel so the movement don't get damaged in shipping hope he does it. This is what ships use to use for Navigation so they could do the math on the chart and use a sextant some thing our Navy should relearn if I was China or Russia taking out GPS satellites would be the first thing I would do if I planning a attack on the USA our Navy would be lost at sea our weapon systems would be out of business we would be screwed. The old school ways are best. The movement a Fusee uses a chain like on a ten speed bike the movement a piece of art. This was made when America knew how to make stuff.
Did find this about the USS Cygnus AF-23 has to be the ship it came off of could of been used by the US Navy. Since this is unique and complicated thought this was the place to post it.
https://en.wikipedia.org/wiki/USS_Cygnus_(AF-23)
http://www.navsource.org/archives/09/06/0623.htm

When this come in I will have the complete set. The Model 21 and 22 and the Hamilton US Navy comparing watch all used by the quarter master for Navigation. Think I mite go after a US Navy sextant to complete the set. The model 22 below with the Hamilton comparing watch.

Looks like you got a nice one Canuck with yoke. Weird I been reading about these for years and kind of wanting one the first time I seen one. This time around after buying one and reading more post about them on various forums I just noticed a few with that yoke I guess not many have it. Could you please point out were the screw is for the stop up screw I do got Whitney books would some thing about it be in one of those books.

So incredibly cool @river rat - congrats. 😎

Some cool info on these
https://nawcc.org/images/stories/public_articles/395_56_63.pdf
Here is Hamilton Model 21 No.1
http://americanhistory.si.edu/collections/search/object/nmah_855355
http://hamiltonparts.com/hamilton.htm

Thanks a lot on that stopping screw info. When I got it today I pulled the corks winded it set the time going forward with the hand never backward or damage can happen gave it a gentle shake and she would not run. I looked between the plates and what did I see a screw between one of the gears got a jewelers screw driver raised it and she ran like a champ. Wonder if the seller thought it was broke why it was cheap and thought I was a sucker looks like I won. Photo of stop screw can't thank you enough for schooling me.

>This is what ships use to use for Navigation so they could do the math on the chart and use a sextant some thing our Navy should relearn

The basics of navigation by chronometer are a part of the Naval Academy course on seamanship so every commissioned officer is taught how to use one (well, two) of these even if they never use them in their careers.

For a while the US Navy stopped teaching old fashioned navigation in the Naval Academy due to GPS a stupid idea GPS satellites can be taken out in a war by the super power like Russia and China.

I will do that when it stops running did not know you can unscrew it until it stops. I got the tub back in the case so mite be safer to let the movement come to a complete stop in a day or two..

Well sent it out for a service. Just sent the movement in it's brass tub corked the balance wheel and double boxed hate mailing larger stuff than wristwatches in the mail but no one in Montana I trust with this. Sent it to some one that works on these so he will know what he is doing. One thing I noticed was when you wind it you don't hear the clicks and the second hand will go backwards a little and the movement will stop. Hoping gunk-up oil is the problem but when I had it running it lost 2 seconds a day so keeps fair time. I bet the last time serviced was what's on that old receipt. After WW2 a lot of these were sold as surplus Jewelry stores that sold Hamilton watches had these in the store windows so people could set the time to the correct time on there watches plus good for advertising Hamilton watches a little piece of watch history.

What a beautiful piece. I love this whole thread! 😀

Well Friday I got her back from service. The only part needed to be replaced was the detent trip spring during the service. For time keeping +0.5s not bad.
When I was waiting for the movement to come back I replaced the missing leather carrying strap and also found a extra serial number plaque in the inner box so also replaced the missing tag on the outer box

Before

After

And the brass tub and movement back in it's gimble box. Things fixed the detent trip spring was replaced in the service and brass tub spring loaded cover for the winding hole did not work now it does, when you wound it you would not hear the clicks and if you wound it when it was running the second hand would go backwards a little and the movement would stop all that was repaired during the service. All fixed lucky for me gummy old oil from it's last service in 1958 or 1975 I lucked out with this only 2175.00 in it and that's with the service they sell for more un-serviced on fleabay these days. Saw that buy now at a dam good price and had to take a gamble and it paid off. I am keeping all the patina you see a lot of these were the brass is all shinny and the wood on the boxes refinished but this was a working one you can still smell the sea when you open it up smells like a musty cargo hold when I was in the Navy. The patina like it's history a story you wish you knew more of like what ports of call did it hit around the world. On the inside lid of the inner gimble box written on the plaque on how to cork the movement and to wind it every day a hand written note 9-28-69 15 seconds slow well it's not 15 seconds slow any more back to Navy specs had to think how old I was in 1969 dam 11 years old.