Military Timepieces:>
Precision Time for World War Two
Dennis Chapman Horological Journal Dec. 1995 - Apr. 1996 (Parts 1-5)Dennis Chapman contrasts the background and methods of Chronometer and Deck Watch production in Germany the UK and the USA, emphasising the remarkable achievements of the Hamilton Watch Co.
Introduction
The achievement of the Hamilton Watch Company of Lancaster, Pennsylvania, USA on building a marine chronometer, model 21, from scratch has been described by Richard Good, thus 'Hamilton was to finally produce what is probably the finest portable mechanical timekeeper ever to be made. This was a marine chronometer, produced entirely by mass production methods, which was developed and produced in an exceptionally short space of time'. Equally remarkable was their simultaneous design and production of their 35 size Chronometer Watch Model 22, honoured by its inclusion in Watches by Clutton and Daniels.Both these timekeepers had balances derived from the Hamilton 16 size Railroad Watch Grade 992B. This watch was made in several variants for navigation purposes and supplied to the British Navy and the Royal Air Force and the Navy and the Army Air Corps of the USA.
A very detailed account of the technical development of the Hamilton marine timekeepers is given by Marvin E Whitney in The Ship Chronometer. It provides a unique picture of the technical-industrial culture of quantity manufacture of watches in the United States of America. This was different from that of either Great Britain or Germany. Whitney does not however discuss the political, social and cultural influences which affected the industries in the three countries.
All three nations faced the same problem immediately before and during the war, that although they had planned for manpower, for warplanes, for ships and for munitions they had not foreseen the need for navigational timekeepers until the shortage became important.
This may be in part a belief in the minds of politicians that wars will be short. In 1914 a well loved Uncle of mine wrote to my grandmother, she kept the letter, that he would be home for Christmas, he did not return. The German Army with the same belief developed and produced, at first successfully, the concept of the 'Blitz Krieg'.
The year 1942 was critical for all the combatants and this was reflected in the policies of the governments of Germany and the United States of America in the manufacture of marine timekeepers.
In 1942 the United States of America and Great Britain together lost 8,245,000 registered tons of shipping in the Atlantic and together built 7,182,000 registered tons, in 1943 the losses were 3,611,000 tons and the total launched was 14,585,000 tons of which the USA contributed 12,348,400 tons. Building continued at the same rate in 1944 and Hamilton provided almost all of the marine timekeepers for these ships and their escorts.
1942 was important for the USA as by the end of that year the whole of the Pacific Basin with its population of 450 million and its resources in strategic materials, oil, tin, bauxite and chromium was in the hands of the Japanese. Hamilton modified their Model 21 as a Four Orbit Chronometer Model 221 for use in the Pacific.
The needs of Germany were different, the lines of her communications were largely internal, overseas trade became impossible. Operations by surface ships in the Atlantic had ended. There was trade along the coasts of Northern Europe, in the Baltic, the Mediterranean and the Adriatic. Naval operations, particularly in the channel were carried out by small fast vessels, destroyers, torpedo boats, E-boats and U-boats, these required different kinds of navigation timekeepers. The demands of the Luftwaffe's bomber fleet became important.
German Self-sufficiency
The origin and nature of the German horological industry was very different from that of either Great Britain or the United States of America. That part of it which made chronometers and chronometer watches was the product of German economic policy of the First Reich and that of the newly created German navy in the last quarter of the 19th century.The horological centre of Glashuette, near Dresden was the creation of Ferdinand Adolph Lange who began watchmaking in Glashuette with the support of the state government in 1845. It became a town with many makers of high quality timekeepers of every kind and in which every component was manufactured. In due course the makers of watchmakers' tools followed as did other precision industries.
The firm had in 1878 co-operated in the establishment of the Deutsche Uhrmacherschule Glashuette, a centre of training and research.
The most important product of Glashuette was the very high quality pocket watch, the product of two cultural influences. One was the scientific tradition of Leipzig, Dresden, Chemnitz and Jena, the other the elaborate social status system of the Second Reich; the 25 Federal States which were, 4 Kingdoms, 6 Grand Duchies, 5 Duchies, 7 Principalities and 3 Free Cities. There were 13 courts with their social divisions and ceremonials and the Free cities and Principalities had their bureaucracies.
This society created the demand for watches with elaborate gold cases with lever and detent escapements, with karrusels, with tourbillons, with dates, with self winding and with grande complications. Lange's 1910 catalogue described and illustrated theses watches and introduced them with three pages of technical data.
The task of the German Government in 1942 was not to create a new industry as the United States did or to supplement an almost extinct industry with imports as Great Britain had to do, but to revive a highly developed but latent resource.
It will be useful as a starting point in examining the German industry to recognise that World War Two was a continuation of World War One and to look at the German preparation in the making of navigational timekeepers before 1914.
The Second German Reich was established as a nation state in 1871 with an army and a navy under an emperor, Wilhelm I. From 1878 under a system of protective tariffs, a policy of autarky, self-sufficiency, created, with the growth of the banking system, a modern technically advanced industrial economy. Firms like Krupp, Siemens, AEG, and IG Farben were superior to their British competitors. German shipbuilding was advanced. From 1882 Germany acquired a colonial empire in Central, South and West Africa and in the South Pacific, in competition with other European colonial powers. The German policy was that the 'flag follows trade', that is the empire demanded a modern navy. The navy required chronometers and deck watches.
The first step was the establishment of an observatory modelled on Greenwich, the Deutsche Seewarte in Hamburg in 1875. The tests were competitive and the German navy bought the best instruments. The tests began in 1877 and in the following ten years most of the chronometers were made with movements or parts from Mercer, Kullberg, Johannsen or from Prescot.
Admiral Von Tirpitz, father of the German navy found this dependence on the enemy, intolerable and under the supervision of the Deutsche Seewarte a commission was set up to organise the production of movements and components for marine chronometers. One member was L. Strasser who taught theory at the Deutsche Uhrmacherschule Glashuette. The commission was successful, it identified the latent capacity of Glashütte which played an important role in two world wars, and in the cold war until at least 1988!
The indigenous industry was at first weak. In the period 1886-7 to 1897-8 A. Lange & Söhne submitted five chronometers for test, some of them several times with different balances. In 1898 Jensen, another Glashuette maker, experimented with the pivoted detent, this was repeated in 1900-1 with a Kullberg balance. From then until 1902-3 both Lange and Jensen used this balance. From 1903-4 Lange used the nickel-steel (iron) Guillaume balance, for which he had the German licence. Jensen continued to experiment with a bimetallic balance and palladium balance spring. From 1907-8 almost all Glashütte chronometers had Guillaume balances and from 1911-12 all had the Earnshaw detent. By this date a Glashuette design was established, it was made by other firms including Raabe of Glashuette, Wiegand of Peine, F. Lidecke of Geestemünde and Fritz Tietz of Kiel.
English Components
Some German makers of marine chronometers continued to depend on English movements up to the outbreak of World War I in 1914. Mercer, in his Chronometer makers of the World shows this by giving the last date when different makers completed their instruments. They were Ehrlich of Bremerhaven, 1914, Knoblich of Hamburg, 1914, also one with an early number (old stock?) in 1916, Lidecke of Geestemünde, 1914, he renewed contact with Mercer in 1924, Ludolph of Bremerhaven, 1914, he came back to Mercer in 1929 and Mayer of Brake and Weser, 1914.Chronometer Testing
Von Bertele gives the results of the tests of 1916-7. There were eight makers competing, of whom four were from Glashütte, A. Lange & Söhne, J. Raabe, Uhrenfabrik Union and F. Vetterlein.Fifty-seven chronometers gained class I, of these eighteen were submitted by A. Lange & Söhne and twenty by Chronometerwerke, Hamburg. This Company was set up in 1905 by a group of Hamburg merchants with the same objectives as Von Tirpitz, to be independent of the British!
The effect of the Versailles Peace Treaty 1919 on the production of navigational timekeepers was dramatic. Germany had to hand over all its naval vessels, all her merchant ships over 1600 tons and a quarter of her fishing fleet.
Chronometer Production
Mercer gives the number of chronometers submitted for test by Chronometerwerke, Hamburg, at the end of, and immediately after the end of the war. From these numbers, the numbers made can be deduced. In 1917-18 the highest number was 903, in 1918-19 the highest number was 958 which suggests only seven were made; in the following test period only one chronometer was tested and that with an early number.Using the same method it is estimated that the production of A. Lange & Söhne would have been, 1918-19, 30, 1919-20, 35, and 1920-21, 15. Recovery did not begin until l924-25.
Other disasters were to follow, in 1923 inflation reached 4.2 billion marks to the US dollar and in 1926 there was a deep European crisis, unemployment in Glashütte reached 85%.
From January 1933 under the Third Reich there was a growth in the German armed forces. This was a preparation for war. The German-British naval agreement provided that the strength of the navies should be in a ratio of 35 to 100!
The German manner chronometer reached its highest stage of development in Lange's No. 319 tested in autumn 1918 to Spring 1919, remarkable considering the dates. It had the reverse fusee, an Earnshaw detent of Helwig's design, a Guillaume balance wheel and steel balance spring. It was awarded Class I with the note 'Vorzüglich', excellent-superb. This instrument set the pattern for the later Glashuette marine chronometers.
Craft Vs Mass Production
The last chronometer to this design made by Lange was tested in 1941-42 and awarded First Class. The manufacture of the German marine chronometer, like the English from which it had been copied was a craft. Although the components had a common origin, Glashuette, and many, for example, balance wheels, were supplied by a single specialist, they were not interchangeable in the American sense. Thus every chronometer had to be adjusted by a 'Reguleur' (English - 'Springer').The importance of the Reguleur was recognised by the Deutsche Seewarte which from the 1927-28 tests recorded the name of the Reguleur of all the chronometers tested. From this date, every chronometer, but one, made by A. Lange & Söhne and submitted to the Deutsche Seewarte, until the ending of tests in 1938-9 was regulated by Paul Thielemann. He was believed to have been largely responsible for the success of A. Lange & Söhne as chronometer makers.
In contrast to this, and to the importance of the 'springer' at Mercers, the precision mass production of Hamilton made the performance of their chronometers largely independent of the intuitive skills of the 'springer'.
Precision Time for World War Two, 2
Dennis Chapman Horological Journal Jan. 1996Dennis Chapman details the production and testing of German Deck Watches and Chronometers and the development of the standard Einheits Chronometer in 1942.
Deck Watches and the Einheits Chronometer
High speed, small warships needed a high quality timekeeper, more robust than the traditional chronometer, the Torpedo-boat chronometer. Most of these had a lever escapement.In World War I the United States Navy adapted high quality 16 and 18 size watches for this purpose.
In 1915 A. Lange & Söhne made 25 Torpedo Boat chronometers for the Austrian Navy. These had full plate movements with going barrels, lever escapements and ran for 56 hours.
In Germany in 1935-36 the Deutsche Seewarte asked Lange to develop a going barrel, lever escapement chronometer, probably, in connection with the design of the small high speed, warship the E-Boat. It had an integral balance wheel by Griesbach with a steel cylindrical balance spring and ran for 35 hours. The hands were set with a small wheel outside the bowl (probably related to the short duration of each service). Two experimental models were made with Nivarox balance springs. Lange made two series beginning in 1936 with numbers 1001 to 1164 with a brass lever and 20mm diameter balance wheel and numbers 1165 to 1430 with a beryllium lever and an l8mm balance wheel, production ended at the end of 1942 with the introduction of the Einheits standard chronometer.
Whitney describes and illustrates a going barrel lever chronometer by Wempe, successor to Chronometerwerke, Hamburg, it had the cylindrical balance spring with mono-metallic balance wheel. It ran for 32 hours and had the same external device for setting the hands as the Lange going barrel chronometer.
Von Bertele shows another going barrel, lever chronometer by Wempe, it had a two-day movement, with cylindrical balance spring and integral balance. It was housed in an airtight metal box to protect the movement from the effects of changes in air pressure as a U-boat dived or surfaced.
Mercer mentions another lever chronometer with a patented balance, made for the Luftwaffe by Wempe.
In 1942 the German Admiralty decided that all detent marine chronometers must be made to a standard design, the Einheits Chronometer. An illustrated description and detailed specification was set out in the Lehrbuch der Navigation (see ref. 7). The 56-hour movement had a reverse fusee and could have either a chain or a flat alloy steel band by Sandvik of Sweden. The escapement had an integral balance wheel by Griesbach of Glashuette. The detent was of the Helwig design but the detent lock was not of his elegant design of an eccentrically mounted capstan but a simple screw held in place by friction. The dial was 100mm in diameter, of aluminium engraved with black numbers. It had dials for up and down showing 56-hours and a small seconds rings.
Apart from the detent lock, the only obvious difference from the Glashuette model was that the barrel bridge had lost its double curve. The gimbals were set in a simple mahogany box with one, glazed, lid.
The chronometer was shown in photographs in the Lehrbuch, in its box and separately in detail. The movement was 'skeletonised' so that the parts could be seen through the dial, below the dial, through the mainspring bridge and through the balance bridge. In the photographs all the parts were lettered and could be referred to a list. There were also similar photographs showing details of the winding and the escapement.
The most important makers of the Einheits-Chronometer were A. Lange & Söhne, and Wempe Chronometer Werke of Hamburg. It is not known if other firms participated.
The tests of the Deutsche Seewarte ended in 1938-9, in the period between this date and the introduction of the Einheits-Chronometer at the end of 1942, Lange made number 715 to 830, of their traditional chronometers.
The first hatch of Einheits-Chronometers Nos. 5001 to 5110 were made by a collaboration between Lange and Wempe. Wempe made the movement using a power train from Glashuette. From January 1943 the chronometers were completed and regulated by chronometer makers in Glashuette.
These chronometers had a detent escapement, with fusee and chain, or steel band. The chronometer was housed in a bowl of plastic material. This collaboration appears to have been a response to an emergency.
From this date until April 1945 Lange made Numbers 5111 to 5550. They had a nickel steel balance wheel with a 38 mm high rim.
The Reguleurs throughout this period were Paul Thielemann, Gustav Gerstenburger, E. Kuhns and R. Scharpenkant. It is perhaps evidence of the shortage of the skills of the 'Reguleur' that Paul Thielemann was 64 years old, in 1945 and Gustav Gerstenberger, 58.
There is difficulty in estimating Wempe's production during World War II. Mercer gives the number of the last chronometer made in each year from which a deduction may be made but there is no distinction between the lever and the Einheits chronometer, Table 1. Mercer states that Wempe bought 300 movements from F. G. Reichelt of Glashuette during the war.
From Mercer it appears that Wempe was making chronometers as late as 1982. Their advertisement suggests that it was the Einheits model. These were probably made in collaboration with Glashuetter Uhrenbetriebe GUB who continued to make this chronometer in large numbers for the Russian Navy in association with the Kirov works of Moscow.
The Russians, more recently, exported these chronometers to the USA and to Great Britain, to Sewill of Liverpool.
Table 1: Wempe's Output 1940-46
Date Last Number Number Made
1938-7 2054
1940 2442 388
1941 2666 224
1942 3019 353 from No.2800 Einheits-
1943 3452 886
1944 4338 581
1945 4119 886
1946 5138 219Early Deck Watches
The making of deck watches for the German navy presented the same difficulties as that of making marine chronometers.In May 1883 the Empire Observatory at Wilhelmshaven published a specification for deck watches (see ref. 8). It was in two parts, the first part set out the physical requirements, its silver case, the diameter of the dial and the seconds circle, etc. The movement was to have a compensated balance wheel and a Breguet balance spring. The second part of the specification was for its performance under tests. The tests were for temperature in two positions. Face up and pendant up, they extended over 135 days.
From January 1887, with the approval of the German Admiralty, the testing of deck watches was taken over by the Deutsche Seewarte of Hamburg. The observatory raised the standards of the tests and encouraged the German watchmakers to become independent of foreign components.
A Lange & Söhne of Glashütte had experimented with the design of lever pocket chronometers, in particular the use of a larger balance wheel. In 1882 they made a 30-hour watch with 2/3 plate movement with lever escapement, and cut compensation balance wheel with Breguet balance spring. It had subsidiary seconds at 3 o'clock and up and down at 9 o'clock. It had a gold hunter case. An identical watch was exported to the United States of America.
Lange made a number of pocket chronometers with detent escapements, some for scientific applications others, possibly in competition with eminent London makers. Lange was supplying movements to one English maker, circa 1880. It is difficult to trace all the watches that could be identified as deck watches, observatory watches or pocket chronometers.
From 1890 Lange made watches with fusee and chain and detent escapements. Clutton and Daniels illustrate a watch circa 1890 with spring detent escapement with one minute tourbillon, it had keyless wound fusee, bimetallic compensation balance, spiral steel balance spring with overcoil and regulator. It had up and down indicator and subsidiary seconds. The tourbillon appears, from the photograph to be of a design associated with the Deutsche Uhrmacherschule Glashütte.
A watch made in the same period had a pivoted detent patented by Richard Lange in 1891. In 1902 Lange had made a deck watch with a 2/3rd plate movement, an Earnshaw detent escapement bimetallic balance wheel and a free sprung balance spring. The hands were lever setting. It had up and down indicator and subsidiary seconds dial.
For the Hydrographic Office of Pola, Istria (then in Austria-Hungaria) in 1905 he made an observatory watch with a detent by Grossmann, it showed 1/2 seconds. The order was repeated in 1916 for a watch with auto seconds.
In 1908, Lange made a watch for the Astrophysical Institute in Heidelburg with a 17 jewel movement, fusee and chain, detent escapement, Guillaume balance wheel and cylindrical balance spring.
The making, in 1920, of a watch with a one minute tourbillon of the Helwig design, with detent escapement and free sprung balance spring showed the high level of Lange's expertise.
Grades of Deck Watch
After a decline in the making of deck watches during and after World War I there was a reaction when the economy improved after 1929. In 1930 and 1931, Dr A Repsold, principal of the Deutsche Seewarte of Hamburg published a series of papers 'Chronometer und Taschenuhrprüfungen an der Deutschen Seewarte'. These papers were an extensive study of the purpose of testing and the relationship between the standards of the tests, the design of accurate time keepers and their functions. The papers questioned the basis for the traditional tests with their Klasse I and Klasse II for scientific purposes including navigation. He prepared new tests, checked against the observatory's pendulum clock. These tests could be compounded into a single measure, the 'Gütezahl' quality number, corresponding to the Greenwich Trial Number.Repsold proposed a new higher class 'Sonderklasse' - special class to be more exacting then the earlier Klasse I. As with the Greenwich Trial Number, the Gutezahl was calculated from a number of tests and a maximum number set for each class. The maximum for the Sonderklasse was 37, for the new Klasse I and for the new Klasse II 120.
To illustrate the working of the new system Repsold gave the details of all the tests and the Gutezahl of seven pocket chronometers. One by Assmann can be ignored, it was damaged.
The first, included to show the possible limits of a mechanical timekeeper, was a student masterpiece by M. Hamm, made under the guidance of A. Helwig at the Deutsche Uhrmacherschule, Glashuette. It had a tourbillon with detent escapement, a nickel steel balance wheel and a free sprung spiral balance spring with outer curve. Its Gütezahl was I 3-56. Except as an example of what was possible, this was not relevant to the production of commercial deck watches.
A. Lange & Söhne submitted five instruments, two with 57 mm movements, one with a 45 mm movement and two with 43 mm movements. The 57 calibre movements were of Lange's highest quality, they had 22 jewel going barrel lever movements, with nickel-steel balance wheel and a spiral balance spring with inner and outer end curves. They had an up and down dial and a subsidiary seconds dial. The hands were lever setting. The watches ran for 40 hours The Gütezahl for each was 23-51 and 23-99. The 57 calibre was tested at Kew in 1935 and 1936. The 45 calibre watch had 32-hour movements of the same design without the up and down indicator, its Gütezahl was 27-17. The 43 calibre watches were also of the same design as the 57 calibre watch except that they had a 30-hour movement. These had Gütezahl of 36-43 and 36-28. All Lange's watches were in the 'Sonderklasse'. The calibre 43 watch was a standard Lange production up and in World War Two when some were completed by Wempe, Felsing and Huber.
Between 1926 and 1939 some 461 deck watches of calibre 43/37 were made with the dial in degrees, Gradmess-uhren. The hands registered, degrees, minutes and seconds. These were used with the chronometer, sextant and nautical almanac for position finding in terrestrial, marine and aerial navigation, the Greenwich Hour Angle procedure, GHA.
A major change in the making of deck watches, as with the marine chronometer came with the War. In 1941, upon the instruction of the High Command, the heads of the Navy and the Luftwaffe, deck watches of calibre 48 (the 48 mm diameter movement) and 48.l with centre seconds, showing 1/5 of seconds, were to be made in quantity. Calibre 48 was a basic design by Lange that could be adapted to meet different requirements. The watches had to be 2/3rd plate 35-hour movements with 16 jewels, a separate balance cock, and a Guillaume balance, these were made by Griesbach of Glashuette, Breguet balance spring and swan neck regulator. The second dial was at 3 o'clock and the up and down at 9 o'clock the hands were lever set.
The calibers 48 and 48.l were regulated in six positions and for temperature and to keep time to under plus or minus one second per day. These deck watches were to be tested by a government observatory.
To meet the very large demand by the armed forces for deck watches a programme was organised based on A. Lange & Söhne and the resources of Glashuette, using other watch makers who were 'conscripted'!
Many were made by Lange or had movements by Lange and an associated company Uhrenrohwerke-Fabrik Glashuette A.G. 'Urofa'. Griesbach (also spelt Griessbach) made balances and other Glashuette companies other parts. The conscripted firms were, Wempe of Hamburg, Felsing of Berlin, Huber of Berlin and Munich and Alpina of Berlin. Experts from Glashütte supervised the work of these Companies.
The calibre 48-movement was fitted into three chronometers for the Luftwaffe and for small vessels with voyages of short duration, Destroyers, Torpedo Boats and E-Boats.
One model, named the T-Chronometer was made for Torpedo boats. This had the 2/3rds plate movement with 16 jewels, a Guillaume balance wheel and Breguet spiral balance spring with swan-neck regulator. It was modified by the provision of a longer, lighter mainspring giving 56-hours running. It had up and down at 12 o'clock and seconds at 6 o'clock. The winder was outside the bowl at 3 o'clock. It was mounted in gimbals in a three-part mahogany box.
The other two models had the unmodified 48 calibre, 35 hour 16 jewel movements mounted eccentrically behind the dial. Both had the up and down at 12 o'clock and seconds at 6 o'clock. The winder was at 4 o'clock. The bowl was of a plastic material. The first of these had a l00mm dial, later they had a dial of 65mm diameter. Both of these chronometers had a two part mahogany box.
A variation of calibre 48.1 had an up and down dial, a seconds dial and a centre seconds hand showing 1/5 of a second.
Glashuetter Uhrenbetriebe GUB continued to make deck watches of calibres 48 and 48.1 after 1945.
Pilots' Watches
A model made for the Luftwaffe had a black dial with white luminous hands and figures. It was in a stainless steel case to protect against magnetism.Wempe also made a similar watch for the Luftwaffe based on a calibre 43 Glashuette movement, with black dial, luminous hands and figures with the centre seconds hand showing 1/5 of a second.
The demand from the Luftwaffe for accurate navigation watches was very great. In 1942 Germans built 4337 bombers, in 1943, 4649 and in 1944, 2287. A. Lange & Söhne adapted their 48.l calibre watch as a Fliegeruhr, an airman's watch. It was described in German as an armbanduhr. It had centre seconds, a black dial with luminous hands and figures, it did not have the up and down dial. It wound at 3 o'clock. The movement had 17 jewels and a larger balance wheel, 22mm in diameter, in nickel-steel. It had the swan-neck regulator. The case was 55 mm in diameter. A heavy leather strap was designed to be worn over a flying suit.
Lange also made a calibre 43 Fliegeruhr. The magnitude of the enterprise can be judged from the numbers made. Deck watches and Deck chronometers, 1941 to 1945, 200001 to 205445. Fliegeruhr, with centre seconds, 1941 to 1945, 210,001 to 216,980. The number of the calibre 43 watches made is not known. There were three Fliegeruhr of a different design. They had a dial with an outer ring of numbers to show minutes or seconds and a small inner ring of numbers to show hours. The centre second hand and the minute hand were of the same length, the hour hand was short to fit the inner, hours dial. The dials were black, the figures and hands were luminous.
Walter Storz of Pforzheim made a Fliegeruhr to this design with an 18 ligne Swiss bridge movement with 20 jewels by Unitas. It had the Guillaume balance and Breguet balance spring and the swan-neck regulator.
Lacher & Co. also of Pforzheim made a 22 jewel 22 ligne Fliegeruhr with a Deutsche Uhren-Rohwerke Glashütte movement of a Swiss bridge pattern, it had 22 jewels, a 22mm Guillaume balance wheel with Breguet balance spring.
Gerhard D. Wempe had a 19 ligne Thommen Calibre 31 Swiss bridge movement in his Fliegeruhr. It had 15 jewels, a compensation balance wheel, a Breguet balance spring and an eccentric regulator. The numbers made of these watches is not known.
An 18 ligne watch was imported from the International Watch Co. of Schaffhausen. It had a black dial with luminous hands and figures, it had centre seconds. The movement had 7 jewels, a compensation balance wheel with Breguet balance wheel and micrometer regulator. This watch had an inner case of soft iron as a protection against magnetic fields in the cockpit.
This account of the making of deck watches and chronometers shows the culmination of the policy of Von Tirpitz, the father of the German navy, in laying the foundation of an industry which survived military defeat, inflation and economic crisis and still had the latent capacity to respond, successfully, to the demands of the three services for accurate timekeepers.
Precision Time for World War Two, 3
Dennis Chapman Horological Journal Feb. 1996Dennis Chapman deals with British chronometer manufacture and imports and discusses US developments based on the Railroad watch.
British Chronometers
Compared with the German history that of the United Kingdom is relatively simple and well documented. Alun C Davies in his paper, the Rise and Decline of Chronometer Manufacturing assumed from the evidence of Frank Hope-Jones, that 'Chronometer-manufacturing would be ousted by wireless telegraphy' but does not account for the 'temporarily resurrected chronometer-manufacturing' during the Second World War, wireless signals were not immune from interference. (Another uncle of mine was a Wireless Telegraphist on a warship during World War One).Mercer describes the situation during World War One. "The Greenwich Trials which began with a specific purpose, to supply the Royal Navy with unequalled chronometers had stopped three years previously in 1914". By 1917 there were five surviving firms, Mercer, Johannsen, Kullberg, Usher and Cole and Dent. The latter firms specialising in deck watches. By this date Mercer were self-sufficient in that they could make all their components, the others were dependent on Prescot and Clerkenwell. There was some division of labour between Mercer, Kullberg and Johannsen. Mercer records that "The main problem was finishing and springing".
By 1918 orders had 'nearly vanished overnight' and Mercer diversified, not primarily into horology but into manufacturing where precision was essential.
The making of deck watches had an affinity with both the making of marine chronometers and that of high grade pocket watches. The Kew Certificate was sought after by Swiss makers and by Waltham of the USA. English makers of deck watches were therefore in direct competition with others, particularly the Swiss. With the ending of production by S. Smith of London and Rotherham of Coventry the Admiralty became dependent on Swiss makers.
By 1939 Mercer was the sole producer of Marine Chronometers in the United Kingdom. The numbers made can be deduced ftom the tables of the first number of 2-day chronometers dispatched in each year.
Table 2 MERCER's Output during WW2
Year Unit No. Difference
1938 14800
1939 15100 300
1940 15300 200
1941 15600 300
1942 15900 300
1943 16200 300
1944 16700 500
1945 17100 400The only other source of 2-day chronometers was Hamilton, very small numbers were imported from 1942 onwards.
Mercer made one modification to their designs to simplify production and adjustment, a new detent by Bill Goodman in 1943. From 1940 the box lost its outer lid and was also simplified. Mercer was dependant on Sandvik of Sweden for springs and the Swiss for screws and jewels.
UK Imports to HS Standards
Navigational timekeepers were defined by the Hydrographic Survey in four categories thus.
H.S. 1. The master chronometer with detent escapement. These were tested at Greenwich before 1914 and after that time at the National Physical Laboratory at Kew.H.S.2. The chronometer watch, formerly known as the deck watch had a lever movement, was adjusted for temperature and in five positions. These were also tested.
H.S.3. These were small watches, most 16 or 19 size with lever escapements, adjusted for temperature and in two positions. Most of the examples found have been of a much higher standard, adjusted in five or six positions.
H.S.4. These timekeepers were large or small cockpit instruments with different specifications. Those provided in the United Kingdom by Smiths were based on Swiss 13 jewelled movements by Jaeger Le Coultre, as their pre-war car watches had been. One pattern had centre seconds and a time of trip dial. There were several others without time of trip, one pattern with extra hands mounted in the glass (as a warning?). These were 8-day clocks. Frank Edwards shows a very high quality chronograph by Breitling. Elgin supplied some cockpit timekeepers and some by Waltham have been found.
Much of the information about watches of HS2 and HS3 types has come from Government Surplus sales, these did not distinguish between pre-war stocks and wartime purchases. The information may not be complete but the high quality watches by famous Swiss makers that have been seen were classified as 'Watch Chronometer H.S.2.'
These were 22"', in screw back silver case, without front glass, pendant or inner dust cover. The movement was bridge pattern, Swiss lever and swan-neck regulator. It had lever setting for the hands. One order was for 948 of which 580 had centre seconds. These watches were fitted into the traditional mahogany box with a circular brass container.
A second order in the same year was for a similar watch in a larger steel case with an inner steel dust cover to protect against magnetism. The regulator was eccentric. A third order in 1940 was for the same model in a silver case.
Ulysse Nardin made large numbers of chronometer watches, of these patterns during the war, it is not known who bought them. In 1942 Vacheron & Constantin made a calibre 166, 22"' chronometer watch mainly for the British Admiralty. It was in a silver case, with inner dust back. The movement had 21 jewels, a lever escapement with Guillaume balance wheel, Breguet balance spring and swan-neck regulator. It had centre seconds.
Norbert Eder illustrates the International Watch Company's chronometer watch No. 676439, calibre 71 bought by the Admiralty in 1940. It had a polished nickel-silver case. The movement had 18 jewels, a bi-metallic compensation balance, Breguet balance spring and micrometer regulator. It had lever adjustment for the hands and centre seconds.
Eder says that calibre 71 which began production in 1904 was one of the most beautiful movements that IWC ever made.
Frank Edwards, illustrates the same watch No. 6439 and describes it as having a stainless steel case, a 19"' movement with 16 jewels, made in 1938.
Longines supplied chronometer watches of their calibre 21.29 to both the British and American governments during World War Two. These were 19"', 3/4 plate, 36 hour movements with 15 jewels. The heavy silver case had an inner dust back.
A 24"' chronometer watch by Paul Buhre of Le Locle in a padded mahogany box was seen in a surplus sale but was not examined.
Hamilton supplied size 35 Model 22 Chronometer Watch, H.S.2. to the British Admiralty in two forms, in the deck watch box and in a gimballed mounting in a traditional mahogany chronometer box. After the war these were retailed by the surplus dealers at £15 and £25 respectively!
An unmarked watch imported by, and named H. Golay & Sons Ltd., London, had a 19"', 18 jewel movement with brass and steel compensated balance, centre seconds and white dial. It was set in a 70 mm diameter case. One form was marked H.S. 3. the other had a dial marked in degrees with an additional rotatable ring also marked in degrees; marked on the dial AM. This was for astro navigation.
Other types in the H.S.3. category were size 16 from the USA and 19"' from the Swiss. They were issued in simple mahogany boxes with a sight glass in the lid or as pocket chronometers to officers in the British and American armed forces. Two Swiss makes have been traced, Zenith and EMT, with 17 jewel movements and screw cases.
There are difficulties in establishing the origin of American watches as many of them 'escaped' from members of the armed forces! Two grades of Hamilton size 16 watches were official imports, both were based on the Hamilton Railroad Watch grade 992B. The grade 23, 19 jewel, Chronograph, Navigator, Time and Stop, Watch was imported for the Royal Air Force. Hamilton made 25291 of these. The Hamilton Navigation Master Watch Grade 399B, was made to a British Government order. It had a twelve hour white dial with centre seconds and was seconds setting. The 22 jewel movement was adjusted for temperature and in 6 positions. The important jewels were set in chatons. The movement had the Hamilton ovalising balance wheel with Hamilton Elinvar Extra balance spring and a swan neck regulator, 2494 were made. The example I have is engraved A.M. 6B160. However, Roy Ehrhardt states that these watches were intended for the navy. They could have been issued to both services.
The Elgin National Watch Company made two 16"' watches, both H.S.3. One had a 17 jewel movement, five of the jewels set in chatons, it had a compensated balance with Breguet balance spring. It had a white dial with a small seconds ring. The other was a watch with a movement of great beauty and high finish. This was a size 16 B.W. Raymond grade 21 jewel watch. The important jewels are set in gold chatons. It had a compensated balance with a Breguet balance spring with swan neck regulator and was adjusted for temperature and in five positions. It had centre seconds and was seconds setting.
It is not always possible to distinguish those wrist watches which were imported for general service and those which were issued to pilots in the Royal Air Force. There is some evidence that watches by the 'best' makers with black dials and centre seconds were used by the RAF. Examples have been found made by IWC, Omega, Longines and Jaeger Le Coultre. Frank Edwardsdescribes three IWC watches with antimagnetic protection which may be compared with the German Fliegeruhr.
One other category of timers which may have had navigational application were stop watches. These were imported from the Swiss firm Lemania and from Elgin in the USA. One pattern which was used in aircraft, possibly in bombers, was the Lemania dash board stop watch, calibrated so that time equalled distance.
A stop watch which was not understood by surplus dealers, was the Admiralty Pattern No.6 marked Waltham but Swiss made. It was calibrated in yards and was a distance meter as any ex Boy Scout would have known. It was operated thus, flash press, bang stop. Then read off the distance in yards! Similar watches calibrated using the speed of sound under water were designed for use by ASDIC operators.
Precision Time for World War Two, 4
Dennis Chapman, March 1996 Horological JournalDennis Chapman describes the origin of the US Railroad watch and a very special production and marketing philosophy which educated the customer to seek technical excellence and provided a basis for the later development of chronometers whose manufacture and servicing were transformed from arcane skills to standard workshop procedures.
To account for the work of the Hamilton Company of Lancaster, Pennsylvania USA, in World War Two it is necessary to examine many aspects of the technical history, the geography, the politics and the culture of the United States of America. Particularly it is important to recognise the advanced nature of its mass production industries.
The Railroad Watch
Hamilton made a marine Chronometer Model 21 based on the Nardin but which had important features taken from the long-established Hamilton Railroad Watch. It made a Navigating, size 35 Chronometer Watch of a new design but with traditional Hamilton features. In addition it made many Railroad Watches Grade 992B in many different forms.This watch was introduced in 1939 but it had a continuous pedigree back to 1893. Hamilton also made wrist watches and clocks for aircraft.
Mass production depends on having a mass market, or a single large buyer. In America the mass production of breech-loading rifles by Eli Whitney, in the early years of the 19th century, was dependent on large government orders. Mass production also depends on having specialised machine tools working at high levels of accuracy. The market may depend on price or the customers' appreciation of quality of a combination or both. The pocket watch industry illustrates this. In the last quarter of the 18th century the manufacturer of pocket watches in the USA, was of two distinct types, the Railroad watch from 1866 and the 'Dollar' watch after 1877.
Locomotive Engineers and Conductors relied on accurate time-keeping. Many journeys were long, many routes were single track and not all had telegraphs.
On April 19th, 1891 there was a head-on collision between two trains near Kipton, Ohio with a great loss of life. Webb C Ball was employed to survey the railroads of Northern Ohio as to the time-keeping on passenger and freight trains and the times in the towns and cities on the lines, which in turn decided the times at the railroad depots. He found that there was no standard for timekeeping on the trains, where at the worst he found Engineers and Conductors using dollar watches and some Conductors of freight trains with an alarm clock hanging on a nail in the caboose. There were no standard times in towns and cities.
From 1893 a national standard was established for the Railroad Watch, it had nine provisions:
1. Must be of 18 or 16 size.
2. Have a minimum of 17 jewels.
3. Be adjusted to 5 positions (later to 6).
4. Keep time to plus or minus 30 seconds per week.
5. Be adjusted to temperature, 400 to 950 F.
6. Must have a double roller.
7. Must be lever set.
8. Winding stem at 12 o'clock.
9. Must have a plain Arabic dial with heavy hands.Mr Ball established standards and made inspections for 54 railroad companies and initially approved 37 different watches. Later in 1915, reduced to 19, 18 and 16 sizes.
His standards were higher than the 1893 specification, it included a Breguet balance spring, a patent swan neck regulator, adjustment for isochronism for temperature from 330 to 95 0F, adjustment in 6 positions, rated within 30 seconds a week and to have the winding stem at 12 o'clock on the dial.
The importance of these specifications was that they were based on a study of the watch in use. The requirements of the design for timekeeping were well understood in general terms but their importance is not immediately obvious. The wide range of temperature reflects the range found in the United States. The adjustment for position was important for the work of the Engineer with his many changes of posture, the winding stem at 12 o'clock was protected by the pendant ring and the provision of hour setting was protected against accidentally changing the hands while winding. A feature to be repeated in the 35 size Chronometer Watch, Model 22.
These provisions identify important qualities of the indtistrial culture of the United States industry, the study of work, and the performance of the product and in the process of the manufacture. Other examples could be Ford Model T and the Fordson tractor.
The 19 watches approved by Webb C Ball in 1915 included:
Elgin: Veritas 23 Jewels,
Father Time 21 jewels,
B. W. Raymond 19 jewels.Hamilton: Grade 950 23 jewels,
Grade 992 21 jewels,
Grade 996 19 jewels.Waltham: Vanguard 23 jewels,
Crescent Street 21 jewels,
Riverside 19 jewels.The result was to establish an understanding of quality and value based on an objective assessment of performance.
Marketing Policy
The marketing policy of the three great manufacturers continued to maintain and increase this understanding. For example in a Waltham catalogue the purchaser was advised to choose a high quality movement in a gold filled case rather than a lower quality movement in a gold case. A Hamilton catalogue explained the function of a compensating balance and how the Hamilton watch was compensated for a temperature range of 340 to 100 0F. It explained isochronism and adjustment to position.In contrast to the status conferring quality of the watch in petty Gertnan states referred to earlier, or the 'designer' obsession in the UK market, Hamilton expounded what can be described as an essay in the psychology of timekeeping.
They repeated the argument about case versus movement advanced by Waltham and then developed a new and unique theory:
'A watch actually has a direct psychological effect on the individual who carries it. A man and his watch go through life together, he is more associated with it 'the companion of his working and sleeping hours' than with any other mechanical object'.The essay goes on:
'A watch becomes part of a man's character. It is the guardian of his habits, the critic of wasted moments, a supplement to his conscience almost, as it ticks away one after another the hours and minutes of which his whole life is made'.There was much more, a horological statement of the Protestant work ethic!
This was the situation when three great manufacturers Elgin, Hamilton and Waltham were each producing their best instruments, preferred grades of railroad watches.
Although Hamilton maintained this policy with its size 16 Railroad Watches it gave way to market forces in the 1930s when it made decorated watches in sizes 10 and 12. One, the Platinum, 'Masterpiece' was recommended as an award for commendable services rendered' (or anticipated?).
Early US Chronometers
When the United States of America entered World War One there were no traditional chronometer makers, John Bliss and Company and T S and J D Negus; both of New York, imported instruments from England and France as did the Navy. As in the United Kingdom the govemment of the USA having built up large stocks did not place orders after 1918 and only began to show interest in buying new chronometers in 1939-40 by which time production in the United States had ended.The production of the Navigating (Chronometer) Watch during World War One was, in contrast, an activity of the three great watch makers and the Vail Watch Company which was associated with the Swiss Zenith. The Waltham Box Chronometer was an 8-day lever automobile clock up jewelled to 15 with a larger bi-metal balance and up and down indicator. The Zenith was also an up-jewelled automobile clock. The most famous of the nautical watches was the 18 size Elgin 21 jewel 3/4 plate, Father Time, free-sprung movement described and illustrated by Richard Good.
In 1918 Hamilton produced its 36 size Navigating Chronometer. There is some confusion and contradiction about this instrument. What follows is an attempt to ascertain the facts. This is important because Hamilton production in World War One, was the harbinger of its unique contribution to navigation timekeeping in World War Two and an example of its engineers methods of developing new designs on their experience of existing ones.
The 36 size watch was made in two forms, as a gimballed watch in a three-part chronometer box and outer box and as a silver deck watch in a simple box with an outer box. The outer boxes having the traditional screw holes to fasten them through the bridge. Both types had a 21 jewel 3/4 plate lever movement, the jewels set in chatons, they had 56 hour mainsprings with up and down indicator, the balance had a compensated cut-balance wheel with Elinvar, later Elinvar Extra, Breguet balance spring with a micrometer swan-neck regulator. The movement had a 'motor barrel', a double roller escapement and was adjusted for temperature, in five positions, for isochronism and recovery. The movements were about 3"' in diameter.
The differences between the two types were that the gimballed movement was key-wound and set. It was wound through a hole in the bottom of the bowl which had a dust cover. The open face silver case watch was stem-wound and was lever set. These watches were made between 1918 and 1943, there were 966 boxed and 250 silver cased made. The 36 size watch was not as Whitney suggests a 'completely new model', it was except for its size its jewelling, its main spring and its up and down indicator closely designed on Hamilton's most recent, 1915, 16 size Railroad Watch the 19 jewel Grade 996. The 996 Grade Watch had a 3/4 plate movement, pendant wound and lever set. It had 19 fine ruby jewels in gold setting, motor barrel, double roller escapement, steel escape wheel, sapphire pallets, micrometer swan-neck regulator, 8 micrometer Breguet balance spring and compensation (cut) balance adjusted to temperature, isochronisrn and five positions. The Grade 996 continued to be made until 1928.
The Hamilton Model 21
The history of the design and manufacture of the Hamilton Model 21 14-jewel Marine Chronometer is beginning to pass into folk lore, in spite of the first hand account of the events given by Marvin E Whitney. A L Rawlings writes 'in 1943 the Hamilton Watch Company of Lancaster, Pennsylvania, with the help and encouragement of the US Navy, embarked on a project for the large-scale manufacture of marine chronometers'. The United States Navy's specification number 18C7c February 2nd 1931 chronometers, ships stated that: 'The chronometer shall have the ordinary compensated balance with detent escapement... the hairspring shall be or steel of palladium'. In effect the Navy had requested that the chronometer should be a copy of the Nardin (as the Japanese was).Hamilton refused to accept the Navy's specification. However, when Hamilton was requested to produce such an instrument, William O Bennett, Chief Physicist and originator of Hamilton's differential balance wheel said: 'No, if we have to make it with a bi-metallic balance'.
The Navy gave way. Co-operation with the Navy came after production was begun February 27th 1942.
Rawlings also writes that there was: 'No time for prolonged experiment with revolutionary new designs'. This conflicts with the fact that simultaneously with the production of Model 21 Ernest W Drescher designed and put into production the Chronometer Watch Model 22. Drescher argued that if it had not been a matter of extreme expedience, Hamilton's chronometers would probably have been very similar to Model 22, free-sprung with a slightly larger dial and sweep second hand. It is questionable whether 'extreme expedience' referred to this or the difficulty of persuading the US Navy to accept a new idea! As evidence as the possibility of creating new design, much of which was achieved in Model 22, Drescher designed and submitted the patented 'time-piece setting device' used in Model 22, in August 1942. A more detailed examination of Model 22 will follow that of Model 21.
The Hamilton Model 21 differed from the Nardin in two respects, the balance, wheel and spring, this was completely different and the detent which was a modification. The balance, wheel and spring was first used in the 16 size Railroad Watch, 992E Elinvar.
The balance wheel of which had the uncut stainless steel rim and the arms were of Hamilton's Elinvar, for which they held United States rights (Compare Lange & Soehne). The balance spring was of Elinvar with the Breguet over coils. The 992E was introduced in 1930, Hamilton was not willing to give up the experience of ten years to meet the Navy's specification. The balance wheel of Model 21 had a stainless' steel uncut rim the arms were of Invar soldered to the rim. The arms were constant in length at all temperatures. The rim expanded with an increase in temperature and contracted with a decrease; except at one temperature the wheel was oval. The rim was provided with 24 equally spaced tapped holes and there were 8 conventional balance screws. The combination of the changes in the shape of the wheel and the disposition of the screws gave a range of adjustment of plus or minus 0.5 of a second per day. At each end of the arms there were large timing weights, which changed the rate by plus or minus 40 seconds per day per turn, an adjacent vernier weight allowed a change of plus or minus 2.8 seconds per day. The shape of the rim was stabilised by heating and cooling to relieve internal stresses. The weight of the balance wheel was 5.1 grams compared with that of the Nardin which was 10.2 grams.
The balance spring was made to a 'standard' design, calculated by the Hamilton engineers, it was made in a furnace and stress relieved. The material was Hamilton Elinvar made to a specification in their own laboratory. The design of collet, the collet clamp and wedge pin assured that there was no deformation of the balance spring when fastening. The active length of the spring was the same in winding and unwinding. The amplitude of the swing of the balance wheel was between 1 31g and 11/2 turns, about 300 degrees. The combination of the balance wheel and the balance spring made it possible to dispense with the intuitive skill of the springer. The timing of the balance is explained in a Navy Department's manual. This is a very detailed instruction book of some 95 pages. Balance screws were found in six weights from 100 milligrams to 300 milligrams and timing washers in six weights from 4 milligrams to 20 milligrams. There were also the two timing weights and two vernier timing weights. Hamilton provided two special screwdrivers, one incorporating a liquid balance, to be used when adjusting the balance wheel. The manual set out the effect of changing screws and washers on timing in two tables and the effect of changing screw positions on temperature compensation. There were two instruments to monitor the effects, an oscillator which gave a print out and an electronic comparator which made a comparison of the performance of the chronometer against a standard.
Precision Time for World War Two, 5
Dennis Chapman April 1996 Horological JournalDennis Chapman concludes his account with a description of the design, servicing and performance of the Hamilton Model 22 deck watch, a triumph of mass production in which design and precision engineering eliminated the need for rare human skills.
Hamilton Model 21 (continued)
The Hamilton and the Nardin detent differs from the usual pattern in that it has a twin spring with a space between each ribbon, the effect would be to maintain the detent in line with the detent block. A single spring of the same strength as the twin spring would be narrower overall and provide less resistance to twisting.Section IX of the Navy Department's manualis a complete instruction, step by step, of the procedures to be followed to bring the chronometer to time. The Manual contains a list of all parts, related to five exploded drawings. Although Whitney does record that the United States Navy Observatory did repair chronometers, the intention of the makers was that damaged or defective parts should be replaced. Sections XIII of the Manual is headed Service Tools. As a part of the development and mass production of the chronometer the Hamilton Watch Company found it necessary to evolve special tools, gauges and fixtures as 'the means by which quality was rigidly controlled at no sacrifice in production'. The Manual goes on 'The tools and techniques as identified and set forth in the book are the result of modern Methods of engineering and work simplification'.
Design changes
In the period from September 1942 to May 1944 Hamilton made 432 design changes during the production of the Model 21. There were several reasons for the changes in the Hamilton design. The first was fundamental, the Hamilton was a copy of the Nardin except for the balance wheel and spring and some detail in the detent. It was produced in a different way. Hamilton had been making high quality watches for half a century by mass production. They made many models, some as many as half a million of one grade. They had their own design team, physicists and metallurgists. One of their horologists was L Dubois, a Swiss graduate of the Technicum of Le Locle, was in charge of the making of detents. The first design changes were suggested by highly developed mass production, dependent primarily on precision engineering rather than human skill.The second category of design changes were the result of co-operation between the Hamilton team of engineer-watchmakers led by W O Bennett and a team of chronometer makers of the Naval Observatory, specialists of great technical skills.
All naval chronometers in need of service or repair were returned to the Naval Observatory and from this experience design changes were suggested. A very brief summary of one problem and its solution will illustrate the process. Early in 1943 there had been an excessive breakage of balance and escape pivots. Over 6 months the team from Hamilton working with the Naval Observatory watchmakers made four changes, a change to the outside diameter of the escape wheel from 0.5 16 to 0.518 inches and the thickness of the tip of the teeth from 0.005 to 0.004 inches. The other changes were of the same order to the impulse roller the design and angle of the impulse and locking and unlocking jewels and finally the one piece roller was replaced by separate impulse and unlocking rollers. What was interesting here was that the new rollers were provided in 5 sizes, from 0.249 inches to 0.253 inches outside diameters, as a means of compensating for 'tolerance accumulation'!
An example of a change to facilitate production was 'On the sustaining ratchet wheel, two access holes of 0.08 inches diameter were added in proximity to the winding pawls"... Now it was possible to deflect the pawls beyond the winding ratchet wheel by a probe and to assemble the sustaining ratchet wheel to the fusee with very little trouble'.
There were other changes introduced 'from the stand point of appearance'.
Whitney's detailed account of the 432 design changes is a remarkable, perhaps unique, account of the continuous development of the manufacturing process for the production of a complex machine in large numbers. It is interesting to compare this with George Daniel's Watchmaking which is about the making of a single watch, or a small number of watches, which are expected to perform to a very high standard.
Variations
The Model 21 had a 12 hour white dial with black numerals and hands, Model 121, made for the Army Air Corps had a 24 hour black dial with white numerals and hands and the winding indicator was reversed. Model 221, the 4 Orbit, had separate subsidiary dials for hours, minutes, seconds, days of the week and the winding indicator, other than the dial and several additional wheels in the dial train, the movement was identical with that of Model 21. The numbers made were 8902 for the Navy, 1500 for the Maritime Commission and 500 for the Army and the Army Air Corps. Production ended in 1971 when the total was 13082.Reliability
The observatory tests of marine chronometers are based on carefully controlled conditions, the test of a chronometer at war is very different and cannot be simulated. It is appropriate, therefore, that this part of the text should end with this quotation from Whitney'The Hamilton certainly proved to be a rugged and most reliable instrument under some of the most severe conditions to which a timepiece was ever subjected. Hamilton's chronometers survived, without ill effect, some of the greatest naval bombardments ever known to man'.The Model 22
The 35 size, Hamilton Chronometer Watch Model 22 (see page 65, February HJ), 21-jewel, lever set movement, was designed at the same time as the Model 21, 14 jewel marine chronometer. It was entirely of Hamilton design and replaced the earlier 36 size chronometer watch.Rawlings, on page 365 of the 3rd edition but also in the first edition published in 1944, sets out a specification for a new chronometer to replace the traditional design. He wrote; 'The costly complications of the chronometer, elegant as they are, are mischievous anachronisms". His specification had three features, a four orbit dial (ie 3 subsidiary dials), a going barrel movement and a detent escapement. We know that E W Drescher the designer of Hamilton Model 22 Chronometer Watch was aware of Rawlings' proposals because he responded to them. Hamilton did in fact use two of Rawlings' features, but not in the same instrument. The four orbit dial of Hamilton Model No. 221 was similar in essentials to Rawlings' plan and the Model 22 had a going barrel movement. The movement of the Hamilton watch differed in one other respect from the Rawlings suggestion, it had a detached lever escapement. Rawlings proposed a chronometer escapement.
The two designs had the following in common, a three quarter plate movement with the escape wheel and a flat spiral hairspring with Breguet overcoil under a separate cock, 'like that of a watch'. 'The hair spring would be made of an alloy with a low temperature coefficient of elasticity' in the Hamilton, Elinvar, 'and the balance would be of the Guillaume or the Hamilton type
His conclusion was 'We should then have isochronism of the balance and hairspring and practically of the escapement also, instead of having as at present, large errors due to all three, adjusted to neutralise one another under a given set of circumstances which may not always obtain'. He concludes in the last section of the chapter, 'Such an instrument might be expected to surpass the finest existing chronometers and give a performance comparable with that of the best pendulum clocks'.
Performance
Whitney describes, but does not explain, a feature of the Hamilton 'The extra long mainspring provides a continuous constant driving force to the balance during the 24 hour rundown. In fact, during the several tests conducted at the Observatory, it was utterly impossible to detect any drop in the balance motion or changes in rate over 48 hours of run down from full wind. The watch was designed to run 56 hours'. When Whitney wrote he gave 60 inches as a length of the mainspring, in watches the writer has examined the 'up and down' dial is marked to 56 hours but the movement runs down to 64 hours.To appreciate the effect of the long mainspring it would be necessary to know the type and material of the spring and to calculate a 'mainspring power curve' as George Daniels illustrates in Watchmaking 16, A Helwig, quoted by Von Bertele, shows a curve of a different form but the purpose of the analysis is the same, to identify the 'useful turns', that part of the unwinding mainspring delivering constant force during the 24 hours run down.
The second feature that contributed to the performance of the watch was the balance: the balance wheel, the balance spring and the regulator. This was derived from railroad watch technology. The balance wheel was different from that of Model 21, the rim was of 18% nickel silver and the arm was of Invar. The rim had 32 equally spaced holes, four chronometer type timing weights, without vernier adjusting screws and balance screws for temperature adjustments, these were made in 20 different weights. In the manual there was instruction on the effects of the moving the pairs of screws. The balance spring was of Hamilton Elinvar with a counterpoised collet. The balance was finally brought to time with a cam type micrometric regulator. Each of the graduations on the cam index regulator plate equalled approximately two seconds in 24 hours.
Quality
The quality of the engineering design is to be seen in the winding mechanism described by Whitney thus and illustrated by him. 'The winding mechanism differs from that of a conventional watch in that it includes a planetary system consisting of a winding gear mounted on a unit with a differential sun pinion upon the arbor. The arbor is free to turn (1) a carrier gear, complete with upper and lower planetary pinions, and (2) an alternating pinion. The alternating pinion meshes with the winding indicator gear. The winding indicator hand is mounted on the arbor of the winding indicator gear'.Only one design change was made in response to a failure experienced in use, a modification of the click spring. The importance of this is the contrast between the manufacture of Models 21 and that of Model 22. Both had the Hamilton Balance Wheel. Model 21 was a Nardin design with 432 design changes made in the first two years of production, none of these were fundamental. Model 22 was a new Hamilton design by Ernest W Dreseher, it had one design change during the same period.
The watch was originally issued in a small deck Watch box and in a gimballed chronometer box. Later the first box was discontinued. The watch was, following the 9.928 Railroad Watch, adjusted to temperature and six positions, however, the watches were tested by the Naval Observatory in the horizontal position face up for 24 days at three different temperatures. The resulting rating was given by Whitney, thus, 'Rating: The deviation of each daily rate from the mean daily rate -for the period in which that rate occurred was to be determined for each daily rate throughout the entire series of tests (except isochronism). The means of all the above noted deviations in the daily rate was not to exceed 0.75 seconds per day. The maximum variation between the daily rate for any two consecutive days in the same period was not to exceed 2.0 seconds throughout the entire series of the test'.
Whitney reports 'On many occasions, the performance record of the 13.531 Hamilton gimballed and 9.780 non gimballed chronometer watches exceeded the performance of many 56 hour standard spring detent marine chronometers. The majority of these watches tested at the US Naval Observatory rated well under the Navy's mean daily rate tolerance of 2.00 seconds per day'.
The republishing of A L Rawlings: The Science of Clocks and Watches 14, reminded me that his comments suggest the possibility of an experiment that could replace speculation With evidence.
The experiment would be to take two Model 22 Chronometer Watches, the first to be modified by replacing the regulated lever balance with a free sprung balance, the Drescher proposal, the second to be modified by replacing the lever with the chronometer balance, the detent, as Rawlings suggested.
The watches then to be subject to the tests prescribed by the US Bureau of Ships or those of the British National Physical Laboratory to discover if either of the chronometer watches 'gave a performance comparable with that of the best pendulum clocks'.
Further Variations
The third group of navigation timekeepers were based on the Grade 992B Railroad Watch (described in the previous instalment of this series). These were supplied with different modifications to all branches of the armed forces of the United States. Some models were provided for the government of the United Kingdom. Grade 992B was described in the Hamilton catalogue thus: 'Grade 992B, 16 size, lever set, 21 jewels. Elinvar-Extra hairspring and mono-metallic balance wheel. Two piece friction fit balance staff. Nickel-silver plate and bridges, nickel plated, beautifully damascened Micrometric regulator. Fully adjusted to temperature and six positions'. The Grade 992B supplied to the services was pendant set. With other 16 size watches by Waltham and Elgin it was described in a service manual, TM9-1575. Between 1941 and 1945 17.146 of the basic Grade 992B were supplied to the United States Government. Grade 4992B, 'Navigation Master' had 22 jewels, the dial had an outer seconds ring with a 24 hours inner circle. It was seconds setting with centre seconds. It had a black dial with white numbers and white hands. The dial was lettered GCT, Greenwich Civil Time. Between 1941 and 1946 96.082 were made. Grade 3992B 'Master Navigation' had a 22 jewel movement with 12 hour white dial, black numbers and hands, it had centre seconds and was seconds setting. These were made for the British Government, between 1942 and 1945, 2.494 were supplied. A model, grade unknown, was made with a 12 hour dial with an inner ring of 24 hours, centre seconds with dial marked Hamilton sid, sidereal time. Another variation of the 992B had the black dial marked with the outer ring in degrees from 0 to 14 and the inner ring in degrees 0 to 330, it had centre seconds. The hands and numbers were white. The movement was the same as Grade 4992B.Comparing Watch
The 'Comparing Watch', Hack or Deck Watch had a 17-jewel movement based on the 992B. It had a white dial with black numbers and hands, it was seconds setting.The Grade 23 'Chronograph, 16 size, Navigation time and stop watch' was also based on the 992B. The movement had 19 jewels. From 1943, 25.291 were made some of which were supplied to the British Government for the Royal Air Force.
An interesting accessory was the 'Case, Carrying Watches, Navigation, US. Army, Air Corps', it was a cylindrical metal box with a sight glass. The 16 size watch was inside in a holder suspended by four coil springs.
Wristwatches and Clocks
Hamilton provided wrist watches for the United States Government but it is not known to which service or services they were intended. On one contract 132.680, 987A 17-jewel, 3/4 plate size 6/0, were supplied between 1942 and 1945. In the same period 31.803 of Grade 9875, the same watch with centre seconds, were supplied. Another wrist watch size 6/0 Grade 2987 had 18 jewels. 15.000 were made between 1943 and 1945. It is possible that the grade 9875 were intended for Navigation. The clue is that Waltham made a 6/0 size, 'Watch Wrist Seconds Setting, Navigation Hack, Type A.17'. It had a dial with an outer ring with seconds and minutes and inner rings of 12 and 24 hours. The dial was black and the hands and numbers were luminous. The Hamilton watch may have been for the same use.Hamilton, like other manufacturers made aircraft cockpit time keepers. Its contribution was the Grade 25 'Airplane Elapsed Time Clock'. It had 16 jewels, between 1944 and 1945, 15.041 were made.
This essay has concentrated on Hamilton's manufacture of navigational timekeepers. Perhaps to complete the account the making of 95.901 map measures might be included. However, the making of some, 29.000 'C.W. Escapement Units Sargamo made 1942-43 were probably intended as delayed action timers for bombs!
Conclusion
In World War Two, three nations faced the same set of problems, the supply of accurate timekeepers for navigation. Two of the belligerents, the UK and the US, had made little preparation, but the latter had the advantage of joining the conflict at a later stage than the others. Only Germany had made some preparation.The position of Great Britain can be described in a few words. There was one maker of Marine Chronometers, there was no maker of high quality watches, there was no centre of horological education. The participation of the Royal Observatory at Greenwich in the testing of chronometers and deck watches had ended in 1913 although the National Physical Laboratory at Kew had continued to provide a service. Throughout the war Great Britain was dependant on imports of chronometer watches, some chronometers and some components. Great Britain had a traditional policy of 'Free Trade' which argued that if a commodity could be bought more cheaply elsewhere there was no point in making it.
The German manufacture of marine chronometers and chronometer watches was the result of direct intervention by the German Admiralty under von Tirpitz, the founder of the German Navy. The influence of the German Admiralty was continued by the Deutsche Seewarte of Hamburg.
The development of the Horological centre of Glashuette by Lange was the direct result of financial support by the State of Saxony. Through Lange and the other Glashotte companies the Deutsche Uhrmacherschule Glashuette was established as a centre of training and research.
In spite of the inter-war disasters the industries of Glashuette retained their latent capacity. In the crisis of 1927 they had the support of a Dresden Bank. Here it must be noted that the structure of the German Reich left considerable economic power in the hands of individual states. When the demand arose, the industry, led by Glashuette and directed by the Deutsche Seewarte, organised the production of the Einheits chronometer and the calibre-48 deck watch, using the resources of the whole German horological industry. With these and one other, the 43-calibre deck watch, the industry was able to meet almost all the needs of the German armed forces. The results of the economic policy of Bismarck and von Tirpitz, Autarky (self sufficiency), were effective three quarters of a century later.
In the United States of America there were no makers of marine chronometers at the outbreak of the Second World War, but there were three large scale mass producers of high quality pocket watches. The US Bureau of Ships invited the watchmakers to submit plans for the making of marine chronometers. EuiIN and Hamilton agreed and both participated, but Hamilton was the most successful. It made the size 35, 21 jewel Model 21 Marine Chronometer, based on the Swiss Nardin using Hamilton Railroad Watch expenence and continuously developed in production.
The 35 size 21-jewel Chronometer Watch was a completely new instrument of remarkable performance that was produced virtually unchanged throughout the war. The Railroad Grade 992B, 16 size pocket watch was made in a number of variants for specific needs and in very large numbers.
The Hamilton Watch Company transformed the production and maintenance of precision timekeepers from an arcane craft to a routine. and was able to meet the demands of the Atlantic and Pacific Fleets of the US Navy and the needs of the Allied merchant marine in both oceans. This achievement, comparable with the mass production of Liberty ships and the ubiquitous 'Jeep', was a triumph of American 'know-how' and 'can-do', which was later to put a man on the moon but, inexplicably, to falter in the market place.
References
1. Good, Richard, Watches in Colour, 1978.
2. Clutton, C and Daniels, G Watches, 1979.
3. Whitney, Marvin, E. The Ships Chronometer, 1985.
4. Kinder, Herman and Hilgenstein, Wemer. The Penguin Atlas of World History, Volume 11, 1978.
5. Mercer, Tony Chronometer Makers of the World, 1991.
6. Bertele, Hans Von, Marine und Taschenchronometer, 1981.
7. Eder, Norbent, Beobachtungsuhren, CalIwey Verlag, München, 1987.
8. Herkner, Kurt, Glashütte, Herkner Verlags GmbH.
9. Davies, Alun, C, 'The Rise and Decline of Chronometer Manufacturing', Antiquarian Horology, Autumn, 1980.
10. Edwards, Frank, 'Watches in Wartime' Horological Journal Vol 136, No 13, July 1994.
11. Ehrhardt, Roy, Egin Watch Company, 1976; Hamilton Watch Company, 1981.
12. Waltham Watch Company, Catalogue', circa 1918.
13. Hamilton Watch Company, The Hamilton Watch, cinea 1918.
14. Rawlings, A L, The Science of Clocks and Watches, 3rd Edn BHI 1993. (Available from Upton Hall, £24.95)
15. Bureau of Ships, Navy Department, Manual for Overhaul, Repair and Handling of Hamilton Ship Chronometer wtth Parts Catalog, 1948.
16. Daniels, G., Watchmaking, 1981.
17. War Department Technical Manual, TM9-1575 Ordnance Maintenance, Wrist Watches, Pocket Watches, Stop Watches, and Clocks, 1945.
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