This is thought to be a one of a kind and is shown
here for your enjoyment. It is an Elgin factory cased 37500.
The celluloid injection molded case is the only one known in existence.
Note the gold washed plates. Also, there is
no serial number on the top plate. It is thought to have been used
to gain final approval of the design and contract for the Hamilton/Elgin
37500 aircraft issued by the USN after the Jaeger/Lecoultre became
unavailable to the US forces. Interstingly, the British smuggled
Lecoultre prodcut from Switzerland throughout the war' but that is a
story unto itself.
This clock was found with a transparent celluloid
dial. Sadly, the dial had shrunk so much it literally pulled away
from its mounting screws and crumbled in my hands. So I skeletonized a New/Old stock dial. I also installed new stainless
The clock is fully functional and is helpful in
explaining how the unit operates. Also, it demonstrates that proper
technique leaves no fingerprints or lubrication smears.
Having serviced/restored these clocks for over 20
years, I researched some facts that explain why so many remain even
though only 40,000 were manufactured (there is a caveat to this number
explained below). Of 300,000 combat aircraft manufactured during
WWII, 56,000 were assigned to the USN or USMC. The total production
of the 37500 went to the USN Bu Aero for distribution. Total
losses for the USN and USMC were around 1,000 combat aircraft. So
the majority of 37500 production survived the WWII. I
suspect most were slavaged from surplus aircraft, but it is unknown how
many were left in the airplane when it was destroyed. I do know
these were assigned to USA helicopters during Vietnam and they were
still on the P-3 equipment list in the late 1990s. Also, I do know
a substantial number of unfinished but serial numbered movements are
included in the production numbers; this is because I purchased at least
20 such movements deep packed and in labeled boxes from when they were
taken off the production line.
These clocks are a testament to US manufacturing
and the use the US Government gets out of its equipment. Many of
these clocks were in continuous service for over 50 years!! And
they still can be put restored to service. The major losses seem
to collector accident and attempts to service them without knowing how.
For those unfamiliar, this clock was a replacement
for the originally specified Jaeger Lecoultre A-10 found here.
There were versions designed for the USAAC and the USN. The
requirement called for a time of trip function, 60 minute chronograph
and civil date (for use in the Pacific). The production and
contract for the 37500 was quite complicated. Hamilton made plates
and screws; while Elgin made wheels and the escapement. They then
shipped parts to each and assemble completed units with their unique
factory specific serial number and factory case.
While I have not seen the contracts, I would
suppose they were paid for manufacturing parts and then again for assembled
units. If you think about the tolerances involved and the need to
eliminate hand fitting of parts, this was an absolutely astounding feat
of American engineering!