The
Hamilton Model 22 Deck watch was designed to replace the marine
chronometer. Hamilton tried to convince the USN to only order
the deck watch but the USN Bureau of Ships was unwilling to take
that risk. By the end of WWII the Model 22 Deck Watch proved
itself every bit as reliable and accurate as the M21 buth far less
damage from handling.
When in service, these watches were
sent only to US. Naval Observatory (and the Norfolk) where watchmakers who knew (and understood) the
procedures for "bringing the watch to time". The major
advantage of the Hamilton M22 of other deck watches was Hamilton's
commitment to controlling tolerances during manufacture, which they
did since the first day in 1892. Hamilton's approach goes a long
way to explain why the ultimately took over the Railroad watch market
from companies who had been in business for 30 years longer then
Hamilton.
For those other makers, from Waltham to Nardin, a
deck watch in need of repair required the replacement parts to be
fitted to the exiting movement and adjustments such as a) altering the dimensions and shape of
the balance pivots; and, b) the position and form of the balance
spring. These adjustments compensate for age and wear so
that the watch will maintain the same rate (plus or minus a few
seconds or less) across the five of six positions in which a pocket
watch is likely to be held. (see Rating
Marine Chronometers and Precision Watches). For
a broken jewel or balance staff, a replacement could be fitted directly from
stock and virtually no further adjustment was required. Using a
friction fit staff avoided much of the damage that could result from bad
handling during fitting a riveted balance staff. Today
the biggest challenge to the M22 is remaining in service too long
without maintenance which relts in damage form the pivots running while
dry. This results in damage that can only be corrected using
traditional techniques and procedures. Further,
the mainsprings in most M22s are still the original 70 year old blued
steel mainsprings which are fatigued and also liable to breakage.
If you M22 is so fitted, only Historic Timekeepers can replace that
spring with new stainless springs made expressly for HTI in Switzerland.
These springs have a big impact on the timing results. Historic
Timekeeper's Precision Watch Service involves:
- Complete Disassembly
- All Pivots Renewed
- All Hole Jewels Inspected at 50X
magnification
- Simple Cosmetic Work (Screws polished and
re-blued, etc.)
- Balance Dynamically adjusted to position
- Escapement "matched"
- Balance Spring Adjusted
- Case Completely Cleaned
- Timing Adjusted Across Five Positions
- Report of Timing Results
You may want to visit our Approach
to Service Page.
The cost of this service of an M22 is $450 plus
parts if needed. We have most of the original replacement
parts that may be needed. There are other parts we make such as
the safety setting parts which sometimes get broken when users try to
pull the crown up without depressing the safety setting pin.
The
inset shows the broken safety setting spring of a WWII vintage
Hamilton M22 chronometer watch. These parts are no longer
available and have to be made. Just above the inset you can see
a steel part marked with an "X" which is installed in the
watch. That is the replacement part I made. By double
clicking on the image you can view an enlargement of the photo.
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