World War II US Navy Hamilton Deck Watch Chronometer With Original Mahogany Box

When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

World War II US Navy Hamilton Deck Watch Chronometer With Original Mahogany Box :
$1900.00

This is the finest example of theWorld War II Hamilton Deck Watch Chronometer that I have ever seen. The only \"fault\" is minor age crazing of the plastic \"crystal\". The Deck Watch runs very accurately and was last serviced in July of 2013.It is an absolute joy for the collector ofHistorical Timepieces. The HamiltonModel 21 and 22 gimballed marine chronometers and the Model 22 deck watch chronometer were absolutely key to the Allies wareffort. Without them no US Navy ship wouldbe able to navigate successfully since all other sources of chronometers in theworld were essentially controlled by the enemies of the Allied Military Forces.

In creating the Hamilton US Navychronometers Hamilton utilized revolutionary materials and design technologythat resulted in the finest chronometers ever made.

A detailed description of the Model 22 taken from the chronometer book online is appended to this description.

Brand

Hamilton Model 22 Marine Chronometer/Deck Watch

Model Number

Model 22

Description

Mahogany Boxed Marine Deck Watch

21 Jewels, Elinvar/Stainless Steel Balance Wheel, Elinvar l Hair Spring

Power Reserve Indicator on Dial

Luminous Material

none

Case Material

Base Metal

Face Markings

Hamilton, Lancaster Pa., U.S.A

Back Markings

Bureau of Ships U.S. Navy 8833-1943, Chronometer Watch

Crystal Material

Acrylic

Movement

Hamilton Model 22 / Non Hacking

Movement Description

Marine Chronometer Anchor

Movement Markings

none

Serial Number

18532

Date Manufactured

Movement 1942 – Cased 1943

Jewels

Movement bph

18000

Dimensions

size 35

2 5/8 x 3/14

Detailed Descriptionof the Hamilton Model 22 Deck Watch Chronometer

(taken from the chronometerbook online)

As the Second World War loomed, the UnitedStates realised that its navy was going to need a great many chronometers. TheUnited States scarcely had a chronometer industry, and such as were made usedparts imported from overseas, mainly from Great Britain. However, thebelligerents had no spare capacity to produce chronometers for others, andSwitzerland, the other main maker of chronometers apart from Germany andBritain, was in a difficult position: their German neighbour in effect forbadethem to sell chronometers to the Allies. The Hamilton Watch Company stepped upto the mark and began delivery of their Model 21 box chronometer with detentescapement in April 1942; By the end of the war, they had delivered nearly 9000of these very fine instruments. However there was also a great shortage of deckwatches, both for larger ships for transferring time from the boxchronometer(s) and for small vessels where a chronometer-rated watch had toserve as the principal timekeeper. The Hamilton watch company began delivery oftheir Model 22 watch in June 1942. By war’s end, 13,531 gimbaled watches and9780 non-gimballed watches had been delivered. The non-gimbaled watch was inthe form of a large pocket watch in a rectangular padded wooden case, while thegimballed watch was contained in a small three-part cubical case, like the M21chronometer’s but smaller at about 51/2 inches on side. A total of 9,780non-gimballed and 13,531 gimballed watches were made.

At first sight, the M 22 watch mechanism lookslike a large ordinary lever-escapement watch of high quality). Its pillar plateis 2 1/4 inches (57 mm) in diameter. However several features distinguish itfrom previous navigating watches: its motive power is an exceptionally longmainspring in a going barrel; it is jewelled back to the centrewheel; it has Hamilton’s ovalising balance; it has an Elinvarbalance spring, whose elasticity varies very little with temperature; ithas a safety setting button so that the hands cannot be accidentally set whilewinding and it has a hand to indicate its winding state.

Motive power

Box chronometers are fitted with a fusee so thata more-or-less constant power is delivered to the escapement. If the balance isisochronous, that is to say it takes as long to make a full swing whether thearc of the swing is large or smaller, then constancy of power delivery to theescapement becomes of less importance. As will be seen later, the balance hasdesign features that make for isochronism and this, combined with the advantageof the watch being maintained face-up at all times, meant that a going barrelwas fitted, despite its non-uniform delivery of power. Nevertheless, the M22was fitted with a mainspring five feet (1524 mm) long which gave a powerreserve of over 56 hours, though usually navigating timepieces were wound every24 hours at the same time of the day. The power declines in, say, a pocketwatch going for 36 hours. In the first few hours, there is a fairly steepdecline in power which then tends to level off, followed by a steep decline inthe last few hours. The effect of lengthening the mainspring so that the watchruns longer is shown in red, with a less steep initial decline, and a lesserrate of loss of power thereafter. Another advantage of a going barrel is thatthere is no need for maintaining power during winding. The spring fitted to theM22 was 4 mm wide and 0.195 mm thick, with thicknesses of 0.190 and 0.20 alsobeing available as required.

The train

With the exception of the going barrel and itsintegral great wheel, the whole train was jewelled with the escape wheel havingendstones. The purpose of increasing the jewelling beyond the usual seventeenis to reduce frictional losses in the train and to further enhance constancy ofpower delivered to the escapement.

The escapement

This is a pallet lever escapement, jewelled withendstones.

The balance

It is in the balance that the M22 differs fromusual practice of the time. It uses an ovalising balance of a similar design tothat of the M21 box chronometer with a Hamilton Elinvar balance spring withBreguet over-coil.

Unlike an ordinary steel balance spring, onemade of Elinvar has an elasticity that decreases only very little withtemperature, so that correspondingly less compensation is demanded of thebalance wheel. In the ovalising balance, the arms are made of Invar, whichexpands scarcely at all with rise in temperature and the rim is made of18/80 stainless steel. At some temperature, the rim will be circular. With arise in temperature, expansion of the rim will force it into a slightly ovalshape, with the long axis at right angles to the arms, and the moment ofinertia, together with the period of oscillation, will increase. Conversely, afall in temperature will cause the balance to become oval with the long axisaligned with the arms and the period of oscillation will fall, since thedistribution of compensation and timing weights tends to be concentrated in therim. In a normal bimetallic balance with a steel spring, the stiffness of thespring does not decrease in a linear manner with increasing temperature, whileits change in diameter is linear, giving the so-called “middle temperatureerror, but in the M22 balance, such small changes in elasticity and moment ofinertia as do occur are practically linear, so that the middle temperatureerror is reduced to an almost undetectable fiftieth of a normal compensatedbalance and is opposite in sign.

There are 28 holes for temperature compensationscrews around the rim. Hamilton provided a procedure for adjusting thesescrews, by checking the rates at 55 and 90 degrees and moving screws around therim according to a table which gave the changes in position necessary tocorrect a given plus or minus change in rate in seconds per day per 35degrees Fahrenheit. There are also four nuts for poising after such a changeand the daily rate was coarsely adjusted by the two pairs of timing nuts, withfinal rating being carried out using the regulator.

The balance spring

The Elinvar balance spring itself was pre-formedand heat-treated on a former so that all springs were pretty well identical andno tedious (and perhaps somewhat intuitive) hand adjustment of the overcoil wasnecessary for isochronism. The central collet was counter-poised to allow forthe weight of the pin and the asymmetry of the first coil. The balance stud waspentagonal, with a hole of matching shape for it in the balance cock.

The Regulator

As in most fine watches, there is amicro-regulator to allow very small movements of the regulator for finalsetting of the rate. The regulator cam and index plate move together about acommon axis and the end of the regulator is held against the cam by the regulatorspring. Each division of the index plate represents a change in rate of about 2seconds per day, so very precise regulation is possible.

Safety setting

When it was important never to “lose the time”,as for example on railroads and for navigation out of sight of land it wasusual to provide some way of preventing accidental re-setting of the hands whenre-winding. The American railroad watches were most often lever-setting, thatis to say the front glass and bezel had to be unscrewed to expose a tiny lever,which had to be pulled out before the hands could be set while box chronometerhands were usually reset, to Greenwich Mean Time, at the conclusion of avoyage. The M22 had a safety setting button to the left of the winding button.

The mechanism of the safety setting is perhapsof some interest, but to help in understanding it a few words about winding andsetting generally may be useful. When the winding stem is in its normalposition and is rotated, a square formed on it and passing through the clutchcauses the latter to rotate and, since the clutch is engaged with the windingpinion, it too rotates with the winding stem. Its teeth are engaged with thewinding wheel which in turn causes the mainspring arbor to rotate and thespring is wound up. A pin in the setting lever engages with a groove in thestem. When the stem is pulled outwards, the pin causes the setting lever torotate, so that a shoulder formed on it pushes the clutch lever inwards and theclutch is disengaged, while a pinion formed on the other end of the clutchengages with an intermediate setting wheel through which the minute wheel andcanon pinion are caused to rotate, thus resetting the hands. The windingpinion, being disengaged from the clutch of course remains stationary duringsetting. Note that when the setting lever moves inwards, it slips from a groovein the setting cap spring and that the spring has a projection that nearlycloses a gap between it and the mounting base of the spring.

Winding indicator

In an ordinary box chronometer the mechanism todrive the winding indicator is simple: a pinion which rotates with the fusee asthe clock runs down, is simply geared to the indicator hand. As the clock iswound it moves one way and as it runs down it moves the other. However, mattersbecome more complicated when there is a going barrel, for when being wound, itis the arbor that rotates, but when running down it is the barrel that rotates,so that no simple gear train will suffice.

As the winding wheel rotates during windup itcauses the windup gear of the planetary gear cluster to rotate clockwise andwith it the differential sun gear (lower left of diagram). Since the carriergear is held stationary by the near-motionless barrel gear, the upper planetarypinion rotates together with the lower planetary pinion which then causes thealternating pinion to rotate clockwise. The alternating pinion is geared to thewindup indicator via the reduction gear and the wind indicator also movesclockwise (when viewed from behind, as in the diagram) to indicate “Up”.

As the clock runs down (lower right of diagram),this time it is the windup and differential sun gear that remain stationarywhile the barrel gear rotates clockwise. This causes the carrier gear to rotateanticlockwise and , as the upper planetary gear rotates around the sun gear itcauses the lower planetary gear also to rotate. This tends to drive thealternating pinion clockwise, while rotation of the lower planetary pinionabout the axis of the sun pinion tends to move the alternating pinion anticlockwise.The latter dominates with the result that the alternating pinion movesanticlockwise and the winding indicator moves towards “Down”.