Hamilton 987S 1940 Wristwatch, With Hack, On Its Way

[WillFly]

Watchitis struck while trawling through eBay yesterday. I spotted a beautiful wrist watch which satisfies my lusts on two counts:

 

(a) it's 1940

(b) it's a Hamilton

 

So... I saw, I sniped, I won. I'll post a better movement pic when it gets here. For the moment:

 

[DJW]

Beautiful Watch! And, I love that dial Will! I'll have to keep this design in mind when I send off my next dial to be refinished!

[autowind]

Thats a very nice watch Will,  you have a very good eye for watches,  you will have to stop buying for 6 to 12 months in order to give others a chance.  :thumbsu:

[Geo]

I have to agree with Don and Roger, it's a really nice timepiece!

By the way Will, I've been abstaining from looking at watches on Fleabay for over a week now, it's not easy. :-(

[WillFly]

I have to agree with Don and Roger, it's a really nice timepiece!

By the way Will, I've been abstaining from looking at watches on Fleabay for over a week now, it's not easy. :-(

 

I know, I know. Do you get the shakes as your trembling hands moves to the eBay bookmark on your browser...? :-)

[Geo]

I know, I know. Do you get the shakes as your trembling hands moves to the eBay bookmark on your browser...? :-)

Ooooooh yes!

[dbals]

You had me at Hamilton....  :) 

[WillFly]

Well, it arrived today and I'm over the moon. It's a beautiful little watch in superb condition - especially considering it was made in 1940. I've photographed the movement in all its glory. Note the hack - which works perfectly.

[autowind]

Older than me and in better condition,  a nice find Will.

[Geo]

Nice watch Wil, but I can't see any hack. :-( Where is it hiding?

[WillFly]

Sorry Geo - should have said - the gilt wheel on the very top of the movement is a feature of Hamilton hacking movements. When the crown is pulled out, a lever operates on the wheel which, in turn, stops the hands. That's how it works, as far as I know - and I'm sure that others better qualified will correct me if I'm wrong! There's a similar wheel on the top of the movement of my Hamilton 4992B "GCT" pocket watch.

[DJW]

I found this picture of the Hacking mechanism for the 987s. You can see the hacking wire in Wills picture just below the 4th wheel where the center, 3rd and 4th wheel all converge.  

[WillFly]

Thanks - a much better explanation than mine - but the top gilt wheel on the movement is only present in Hamiltons with a hack mechanism - so I wonder what the function of the wheel is in relation to the hack? (Adds a Homer Simpson "Doh!" at this point...)

[DJW]

The gilt wheel on top of the bridge is pressed onto the 3rd wheel pinion and just drives the center seconds hand. Most manual wind movements with a center seconds are designed this way. They can have a hack mechanism or no Hack.

[Marc]

Actually Will the large gilt wheel on top of the movement is a feature of pretty well all indirect driven centre seconds designs and is pressed onto the third wheel arbor which is extended through the bridge and from which it transfers the drive to the centre seconds pinion, which is the little wheel right in the centre of the movement with a flat spring on top of it. This design has an inherent amount of slack in it which would show up as jitter in the motion of the seconds hand which is why the flat spring is there; it smooth's out the movement of the hand.

Hacking systems usually take the form of a lever or arm that impinges directly on the balance when the crown is pulled out, stopping the whole watch.

Stopping a movement by interrupting the hands would not be a good idea as the gearing would mean that the escape wheel could continue to rotate for a short while building up torque within the wheel train. This may not be good for the train and could cause inaccuracies in the synchronisation of the watch when the hack is released and the torque causes the movement to "catch up" a little.

I suspect that the hack in your very beautiful Hamilton operates directly on the balance, although I have no experience with this particular movement and would happily stand corrected.

[WillFly]

Thanks guys for the very clear explanations. Because this gilt wheel is only obviously present in my hacking Hamiltons, I had always assumed it bore a direct relationship to the hacking mechanism. Your replies show the difference between those of us with just love of watches - and those of us with love and knowledge of watches! :bow:

 

The only other watch I have with a hack function is my Seiko Solar - and I've never dared take the back of that!

[Marc]

DJW, as I mentioned above, the large wheel running on the extended third wheel arbor to drive the seconds hand pinion is a design feature of "indirect drive" centre seconds wheel trains. This was one of the earliest designs to bring the seconds hand to a common axis with the hour and minute hands and is common on many vintage watches with centre seconds up to maybe the mid sixties (ish). However, it has two problems. Firstly, there is the "jitter" of the seconds hand unless a tension spring is employed in which case the correct adjustment of the spring is vital if the proper running of the watch is not to be disturbed. Secondly, it increases the thickness of the movement, and therefore the watch.

To address these issues the "direct drive" centre seconds wheel train was developed and became the adopted "norm" for very nearly all centre seconds movements from then on. Only a very few high end watches still use indirect drive for the seconds hands.

[DJW]

DJW, as I mentioned above, the large wheel running on the extended third wheel arbor to drive the seconds hand pinion is a design feature of "indirect drive" centre seconds wheel trains. This was one of the earliest designs to bring the seconds hand to a common axis with the hour and minute hands and is common on many vintage watches with centre seconds up to maybe the mid sixties (ish). However, it has two problems. Firstly, there is the "jitter" of the seconds hand unless a tension spring is employed in which case the correct adjustment of the spring is vital if the proper running of the watch is not to be disturbed. Secondly, it increases the thickness of the movement, and therefore the watch.

To address these issues the "direct drive" centre seconds wheel train was developed and became the adopted "norm" for very nearly all centre seconds movements from then on. Only a very few high end watches still use indirect drive for the seconds hands.

Thanks for the more detailed explanation Marc, but I thought that's what I said? :D

[Geo]

Thanks for the detailed info Guys, I really appreciate it. :-)

I've worked on a few watches with centre seconds wheel, but not with a hack function.

[DMS]

A very nice looking watch, I only wish I had the knowledge to be able to discover some little gem like this, Will I am green with envy my friend.  :)

[WillFly]

A very nice looking watch, I only wish I had the knowledge to be able to discover some little gem like this, Will I am green with envy my friend.  :)

 

Well, I suppose one's personal preferences regarding budget, make, dials, age, style, movement, country of origin, etc., all play a part in deciding what to look for. It's difficult to put into words exactly, but I suppose my criteria - over time - embrace:

 

1. Age: timepieces from before 1970 and preferably from 1930-1960'ish

2. Style: classic or genuine military (not military-style), no divers watches - can't stand chunky bezels

3. Movement: not necessarily heavily jewelled movements, but well-finished, preferably American, then Swiss, then German, then French...

4. Power drive: hand-wound,  no batteries, no automatics (too much bother) - but I admire the technology in Solar watches and have one of those

5. Country: American watches, particularly railroad grade pocket watches, then Switzerland

6. Makes: Can't afford posh makes, so good names like Hamilton, Waltham and Elgin (all US, not Swiss versions), Roamer, Gruen Curvex, Wittnauer, Oris, Omega, etc.

7. That indefinable something... chronographs when I can afford them!

 

And so on! I check European makes against http://www.mikrolisk.de/ which is a rough guide to origin

 

So, as far as getting the Hamilton, it immediately ticked a few boxes: (1) make (2) year (3) style (4) condition - and I just had to snipe it!

Edited May 24, 2014 by WillFly

[Geo]

no automatics (too much bother)

Too much bother???

You being a guitar player I thought that would have been the best type for you! :-)

[WillFly]

Too much bother???

You being a guitar player I thought that would have been the best type for you! :-)

 

Ah, but the watches go on the left wrist - and the playing movement's done with the right... :jig:

Edited May 24, 2014 by WillFly