Marine: Marine Chronometer Hamilton Model 21 . Help to Dating

Discussion in 'Chronometers' started by Waltom, Apr 2, 2018.

  1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.
  1. Waltom

    Waltom Registered User

    Aug 20, 2013
    11
    0
    1
    Male
    Poland
    Country Flag:
    Hi there Everyone,

    few day ago I bought marine chronometer made by Hamilton Watch Co.
    On the dial is number N4032 , on movement is 2E4032. I'm looking for production date. On the another thread I found that chronometer serial number 2E6244 was finished in September 1944, but on the other hand solution for locking balance fork by Allen screw was adopted a some time after 1948.

    This Chronometer had overhaul on 1987

    Regards
    Waldemar

    Hamilton.jpg

    Hamilton movement.jpg

    Hamilton przeglad zegara 1987.png
     
  2. Tom McIntyre

    Tom McIntyre Technical Admin
    Staff Member NAWCC Star Fellow NAWCC Ruby Member Sponsor

    Aug 24, 2000
    82,183
    1,497
    176
    Male
    retired SW dev
    Boston
    Country Flag:
    Region Flag:
    Note the small plaque since that serves the same purpose as the externally activated arresting device. After they were specified, I think that Navy Stores put the device on all chronometers that came in for servicing. (Unless they were too busy and needed to get them back out quickly.)

    I suspect the chronometer did not get the overhaul in 1987 that is marked as due on that date. The mark would have been removed had the work been done. the USN disposed of all of its chronometers in storage some time around then. I am sure another of our readers can give you the "official" date. When they were released, they were sold in pallet loads for remarkably little money.
     
  3. DeweyC

    DeweyC Registered User
    NAWCC Member

    Feb 5, 2007
    1,832
    606
    113
    Watchmaker
    Baltimore
    Country Flag:
    Dating M21s is not straight forward. When I purchased several hundred from the USN in the 1990s, I copied the production cards for each one. First, delivery did not start until late 1943 and No. 4 was returned at least three times before it was accepted in early 1944.

    BTW, if one reads a couple hundred of those assembly records, one notes an amazingly high incidence of "bruised pivots" recorded on the notes section on the reverse. Either this was to make it look like Hamilton was inspecting or Hamilton was incredibly (and uncharacteristically) careless in handling. I recall there were several other popular notations.

    The locking device was added by the USN Repair facility in Norfolk Va after the war. I like it, Marvin Whitney did not although he never told me why (not invented at the USNO??) The Allen key they made for it is turned from piece of stock and to my mind is the equivalent of the $500 toilet seat. I provided the straight section of an Allen key inserted into a knurled brass handle.

    These were kept in service until 1988 when GPS was approved as reliable. I have a copy of the order recalling all mechanical instruments from the Fleet in 1988. Quartz was tested in WWII and was used through the 1980s but there were too many problems with drift from the constant pounding and sea air environment.

    The USN had been using the M21 as its backup to Loran and the fact that there were a number of areas where radio reception of time signals was unreliable.

    Prior to disposal of the instruments, the USN had been cannibalizing instruments to keep others in service. The stowage was changed to eliminate the need for the boxes. Hence, in the early 1980s there was a surplus of boxes available for a dearth of instruments; and after the DRMO sales in 1992 the opposite was the case.

    And the stories about navigators removing the lids is true.

    To square the circle, the USNA , USMA (Kingspoint) and Pilots and Mates School all stopped providing instruction in celestial navigation by 2000.

    They are now reintroducing it.
     
    Leigh Callaway likes this.
  4. Paul Regan

    Paul Regan Registered User

    Mar 4, 2003
    685
    49
    28
    Florida
    Country Flag:
    Region Flag:
    Great Info Dewey, Thanks for posting it.
    Paul
     
  5. Leigh Callaway

    Leigh Callaway Registered User
    NAWCC Member

    Sep 5, 2011
    127
    172
    43
    Upper Valley, New Hampshire
    Country Flag:
    Region Flag:
    Dewey:
    Great info, thanks very much. The ledgers available on this site list dates finished and sold. As noted in this forum a few times, there is (as yet anyway) no information about "Sold To." Example below points to my chronometer 2E6688.
    Pictures below are of a key which came with it. Would this be one from Norfolk or could it be one of yours?

    Ledger 2E6688.jpg Locking tool 1.jpg Locking tool 2.jpg
     
  6. Leigh Callaway

    Leigh Callaway Registered User
    NAWCC Member

    Sep 5, 2011
    127
    172
    43
    Upper Valley, New Hampshire
    Country Flag:
    Region Flag:
    To answer Waltom's question - according to the ledgers 2E4032 was finished and sold April 13, 1944 to "64-15634".
     
  7. Tom McIntyre

    Tom McIntyre Technical Admin
    Staff Member NAWCC Star Fellow NAWCC Ruby Member Sponsor

    Aug 24, 2000
    82,183
    1,497
    176
    Male
    retired SW dev
    Boston
    Country Flag:
    Region Flag:
    I don't know of any documentary record, but I have always believed those numbers were purchase contract identifiers. If the purchase records for the U.S. Navy sales were available in the Hamilton archive, more details might be available. I think in all cases the purchaser was the U.S. Government when those numbers appear.
     
  8. Waltom

    Waltom Registered User

    Aug 20, 2013
    11
    0
    1
    Male
    Poland
    Country Flag:
    Leigh Thanks for information about finished date .

    Dewey great information. Does it mean that all chronometer by Hamilton were produced without this solution? Did all blocking mechanisms by Allen screw was add later during services?
     
  9. DeweyC

    DeweyC Registered User
    NAWCC Member

    Feb 5, 2007
    1,832
    606
    113
    Watchmaker
    Baltimore
    Country Flag:
    Leigh and Waltom,

    That is similar to the keys I made; but without bragging, mine were nicer. I put a 1/4 round of brass on it that I knurled, rounded the top and chamfered the underside.

    Waltom, you are correct. No M21 made during WWII came with the Norfolk Balance Break. That was designed around 1948 I believe.

    Leigh, here is a picture of the Norfolk Balance Break wrench. From 1/4 inch stock the then turned an arbor and milled an Allen key on the end. Then knurled the handle. On the right machine it probably took little time. And it IS nicer than my quick and dirty answer.

    IMG_0313 (Medium).JPG
     
    Leigh Callaway likes this.
  10. Leigh Callaway

    Leigh Callaway Registered User
    NAWCC Member

    Sep 5, 2011
    127
    172
    43
    Upper Valley, New Hampshire
    Country Flag:
    Region Flag:
    Dewey thanks again. Knowing a little more about it, I'll start looking for a proper wrench - a Norfolk version. Gotta be one out there somewhere....
     
  11. mdjtlj

    mdjtlj Registered User

    Aug 17, 2009
    19
    0
    1
    Country Flag:
    Dewey, just a slight correction, USMMA (i.e. Kings Point) - United States Merchant Marine Academy has never actually stopped requiring celestial navigation for all the Deckies (as we call them). It was one of my most enjoyable classes there and it really opened your eyes to spherical trigonometry and how the ancient societies navigated by the stars. Thus my fond affliction to marine chronometers.
     
  12. DeweyC

    DeweyC Registered User
    NAWCC Member

    Feb 5, 2007
    1,832
    606
    113
    Watchmaker
    Baltimore
    Country Flag:

Share This Page