So what makes the 16 size grade 950 so special? Lots of things.
When it was introduced in 1910, it featured 23 extra-fine ruby and sapphire jewels. It has a solid gold train - meaning the center wheel through the 4th wheel are solid gold. The train jewels are set in solid gold chatons (settings). It has a low friction motor barrel. Plus is has all of the bells and whistles the "lesser" grades like the 992 had (the 992 is also an excellent railroad-approved watch).
The 950 continued to be produced until the Elinvar hairspring was added in 1935, making it the 950E. The grade was largely unchanged over almost 30 years until it was replaced by the 950B in 1941.
If you want to buy a 950 or 950B you'll need to be prepared to dig deep. They are not inexpensive. You will often see the grade cased in a solid gold case but buyers could also select a gold filled case, if they wanted.
I recently picked up a 950 and based on the serial number of the movement it dates to 1934, just before the Elinvar hairspring was introduced.
This example is cased in a Number 10 "bar over crown" case.
My attempt at the photographing the case back turned out to me more of a self-portrait of my hand and camera.
The best part of the 950 movement is the backside of the movement. It seems a shame to have to cover it.
One of the requirements of railroad certification is to be lever-set. That means there is a lever to move the watch into the time-setting position and you can't accidentally change the time like on a pendant-set movement.
Flipping the movement over, the first thing to do is to make sure the mainspring is released. Then each bridge is removed, screw by screw.
A motor barrel is an interesting design. The barrel has a fixed axle that runs though the center. The arbor that the mainspring attaches to is secured to the ratchet wheel and the axle goes through the arbor and is held in a jewel on the back of the movement.
The hairspring stud is held in place by a keeper on the balance cock. I'll remove the balance from the balance cock so I can thoroughly clean it.
While the parts are being cleaned, I will replace the crystal in the bezel since it has a few edge chips.
A new 19 5/16 Linge crystal will do the trick.
Everything gets thoroughly cleaned and readied for reassembly.
The four train wheels are installed first. They should spin effortlessly at this point.
Next to be installed is the pallet fork and it's bridge. Both sides of the pallet fork arbor are protected by cap jewels.
The barrel bridge is installed and the arbor jewel is secured by three screws.
The movement is now ready to be wound up so I can put the balance back on.
The easiest way to wind the watch at this point is to put it back in the case and use the crown.
Reinstalling the balance means carefully reinserting the hairspring in the regulator index fork. Then I can rescuer the keeper.
With the watch wound up, when I get the balance in the correct place the watch will start ticking. It's looking great now so it's off to the timer.
Not too shabby. I could probably remove the balance and try to reduce the beat error but that would also risk goofing up the balance. So I think I'll leave it as is.
This watch looks as great as it runs. This dial is called the HG dial.
Absolutely a beautiful watch. I would like to get a better grade pocket watch some day. I have a 974 lever set with a Montgomery dial that keeps great time. I also have a 914 in a dress case that seems to keep good time in a pocket but looses time on its back. Does it just have worn parts? One other question as you have gotten me hooked on Hamilton's. If I have a watch that came out of the box with a 747, can I put in a 730 that I have to replace it? Same goes with a 748 and 735. I know that it would not be authentic in the true sense. But it could make a daily wear or work watch out of something that I have is not running. Nice Firebird. My first car was a '67 Firebird with the OHC 6!ReplyDelete
Yes, a watch that runs poorly in on position probably has a bent or worn pivot, likely on the balance staff. Yes, you can swap 747s and 748s with 730/731 and 735/736s. Unless the watch is going into a museum, it probably doesn’t make a big difference. In fact, it’s a bit of an upgrade.Delete
Hi HandyDan, I came across a 950 23 jewel. How rare are these, its in great shape too. Built in 1910 is that correct?Delete
When it was built depends on the movement serial number. It’s not rare but it is a super-high quality movement and expensive.Delete
What a beautiful movement. Never thought I'd want a pocket watch but those photos get me going.ReplyDelete
I think no collection is complete without at least one pocket watch and if you’re only going to have one then a 950 or 950B would be a nice choice. Of course you could get several 17 jewel models for the cost of one 23 jewel 950.Delete
Hi Dan, what is the reason of having cap jewels on pallet fork? I heard in common practice, pallet fork jewels don’t get oiled. Thanks!ReplyDelete
Cap jewels do two things... the act like thrust bearings (potentially) and they keep dirt from getting into the jewels. There are four (possibly six) jewels involved with pallet forks. The arbor has a jewel on both ends (two), the pallets themselves (two) and there could be cap jewels on the arbor (two more). All of the arbors need to be lubricated. The pallets themselves should be lubricated to eliminate as much friction as possible (that's the point, right?) but also to minimize wear on the escape wheel teeth that clang into them. I think the more common practice is to lubricate all of the points of wear. Some might skip the pallet forks but I wouldn't call that a best practice.Delete
Thanks for the response!Delete
Hi Dan, will a Hamilton 950P fit into a Crescent pocket watch case that currently houses a Hamilton 974? ThanksReplyDelete
Definite maybe but more close to definite than maybe. I’m not familiar with a 950P... is it negative set or lever set? If negative set the stem sleeve may need adjustment but you’d have to try it. The movement itself will fit fine though. It’s the winding that could be a challenge. If it’s lever set then as long as the case has a cutout for the lever then you’ll be fine.Delete
I have one that was given to me as a gift and it is in need of a new crystal and repairs. Do you offer these services and approx cost?ReplyDelete
Any competent watchmaker would be happy to work on a 950B. What it would cost would depend on what it needs and it would have to be seen to give you an ideaDelete