World War II Hamilton 37500 Cockpit Clock

Hamilton 37500 Front

The most rewarding projects in watchmaking are the ones you know are way beyond your depth, yet you try anyway (and most importantly succeed.) This Hamilton 37500 aircraft clock was undoubtedly the hardest and most complex piece I have worked on to date.

This clock was one of the most complicated pieces ever made for military aircraft and as such has a huge amount of parts. To avoid too much clutter and confusion, I decided to familiarize myself with the movement and find the problem by disassembling and reassembling it in segments.

The first goal was to replace the balance complete. I knew that this was not working because the balance staff was broken. Once that was done it ticked but stopped. Something more serious had to be going on so with that in mind I went about the rest of the process.

I first disassembled the mechanisms on the front. This included the civil date, date jumper, and the elapsed timer. Once I got all of these properly cleaned I oiled and reassembled them, I then wound up the movement, and although it ran it still stopped after a short time. The problem was not with the front.

I the set about taking the back mechanism, which was the chronograph. Here I noticed something was awry. There was way too much play in the fourth wheel (the gear that drives the second hand and by proxy the chronograph. A closer look revealed that the jewel that holds it had been shattered causing it to tilt and stop the movement.


Fortunately I had a harvester movement on hand. Although expensive, it was no where near as expensive as a service for one of these (almost $1200.) The harvested back plate was perfect and after swapping those out the movement worked perfectly.

Next I disassembled the entire clock. Ultrasonically cleaned everything and got it all back together. Although that only took two sentences to describe, it was way more work than the few words might suggest. After oiling and regulation I made sure that it runs properly through the full 8 day wind. A timing machine can only tell you half the story with large capacity mainsprings so it is always important (although time consuming) to let these clocks run through.

IMG_1912 IMG_1903

Pieces of WWII history like this are always a touch more rewarding than regular restores and come with an extra sense of pride. As does being able to restore such a complicated piece. That being said, it’s back to smaller pieces for a little while.

Hamilton 37500 Front Hamilton 37500 Angle

Hamilton 37500 Tilt Hamilton 37500 Back


Railroad Approved Hamilton Electric Caliber 505

Hamilton Electrics Feature

For anyone who has ever ventured into the repair of interesting watches they have undoubtedly been seduced by the idea of fixing a Hamilton Electric. I can say that there has never been a more frustrating and time-consuming restore than these. They are kind of like the Los Angeles of watches. They combine everything that is wrong with New York (Mechanical watches in this analogy) and Miami (Quartz) and roll it into one city. Their restore encompasses the delicacy of mechanical assembly with the frustration of dealing with electronics to create a watch that many have tried to repair but few have. I succeeded by luck and persistence alone. I do not advise trying this at home. If you do be prepared to face the most annoying piece you have ever dealt with.

All whining aside, this is an incredible and largely forgotten timepiece in the history of horology. Hamilton became the first company to replace the mainspring in wristwatches with their introduction of the Hamilton caliber 500. I tried one of these but quickly discovered that there is a good reason that there is only one person still capable of servicing them (he is also considered the foremost authority on their history.) Compared to the innovations that came shortly after like tuning fork movements and then quartz, the electric watch looks like an odd prop from an old sci-fi movie rather than a reliable timepiece. The truth is that this was the first and arguably most important step in the development of battery powered watches that would first cripple and then fundamentally change the Swiss watch industry.

After years of R&D development at Hamilton they introduced the electric watch in 1957 and coupled this technological breakthrough with fantastically avant-garde case designs for the time. They were produced for 12 years. The fact that they were made for a relatively short period of time coupled with the fact that they were made by only one company make them an absolute nightmare to track down extra parts for.

Used with permission of Rene Rondeau

Used with permission of Rene Rondeau

These two Railroad Approved models attracted me with their simplicity. The offset crown and the lightning bolt second hand very subtly indicate that something is different about these watches, but it is not apparent until you look under the hood (so to speak.) Their size is also very large for that era.

It took several re-assemblies and tweaks to get these things going strong, and now that they are I can safely say that I will never venture near one of these ever again but am very happy to have done so and added them to my work history.

Check out the video below of these two movements running!

P.S. – Should you need yours repaired I highly suggest contacting René Rondeau (the guy I refer to earlier as the one person capable of repairing caliber 500s) at He is THE authority on these pieces and the only one I know of capable of professionally restoring them.

Hamilton Electric Gold Side Hamilton Electric Stainless Side  Hamilton Electric Stainless Dial Hamilton Electric Stainless Front Hamilton Electric Gold Front

1966 Vintage Omega Caliber 560 with Linen Dial

Omega Linen Dial Feature

The time has finally come where I am posting about the same movement twice. This Omega has a Caliber 560 exactly like the 1967 Omega back in early July. Other than the gold plating and the movement the two watches are incredibly different. What drew me to this watch before I even saw the inside was the linen dial. I am a sucker for rare variants when they are in good enough shape. Little things like this (especially in this condition) can add a lot of value to otherwise standard pieces.

Usually this type of textured dial is a magnet for dirt and before long the white linen begins to look more beige. When I saw such a fragile dial in such great shape I knew that the movement would be in equally well preserved. Fortunately, I was right. When I got the back open I was staring at the most well preserved caliber 560 I have ever seen.

The case had no service marks, and as can be seen the movement is in incredibly good shape. Due to this watch never being serviced the oil had dried or migrated and so the rate of the watch was off by 35 seconds per day. After a full disassembly, cleaning, oiling, and regulating this piece from the 60s is beating properly and keeping excellent time.

Back together and on a new band this is a classic, rare, and near mint dress watch that wonderfully showcases the timeless elegance of vintage Omega. Omega Linen Dial Angle Omega Linen Dial Close-up Omega Linen Dial Side Omega Linen Dial Movement Omega Linen Dial Movement 2