Difference between revisions of "WW1 Military Watches"

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The archetype for British aviation watches was established from the start:
 
The archetype for British aviation watches was established from the start:
  
*an 8-day Swiss movement was used for the works (even in the Mark V, which allowed otherwise for 30-hour movements);
+
*nomenclature was applied to the dial (specifying, amongst other things, the contracted supplier of the watch)
*nomenclature was applied to the dial (specifying, amongst other things, the contracted supplier of the watch);
+
*both luminous and non-luminous versions of the watch were issued
*markings were applied to the case to indicate military issue (except in the Admiralty Marks);
+
*markings were applied to the case to indicate military issue (except in the Admiralty Marks)
*both luminous and non-luminous versions of the watch were issued.
+
*an 8-day Swiss movement was used for the works (even in the Mark V, which allowed otherwise for 30-hour movements)
  
=====Eight-day movements=====
+
=====Nomenclature to the dial=====
  
Before the 30-hour Mark V standard was formulated, the British aviation watch used 8-day movements from a variety of Swiss makers (not all of them identified). It is likely that 8-day movements were chosen for their inherent stability and accuracy rather than in anticipation of extended flying times. It was probably not until manufacturers could prove that 30 hour movements matched that requirement that the Mark V was specified and produced. (That is to say, the later adoption of the 30-hour watch reflects the evolution of Swiss watchmaking rather than a change in military requirements).
+
The dials carried as a minimum the name of the supplier and the spec that it was intended to address (eg Mark IVA).
  
'''Octava Watch Company 8-day movement'''
+
Individual serial numbers came to be applied later and most incorporated a letter code that identified the supplier. It was British standard practice during WWI to mark military equipment supplied under contract in this way.
  
:An 8-day ¾ plate nickel movement; 15-jewelled; club tooth and straight line lever escapement; bimetallic compensated cut balance.
+
The Mark V watches did not carry manufacturer’s names to the dial, but they are identified by their digraphic letter codes (and branding did appear to the movements, cuvette, inner case back, etc).
  
:Typically, the movements are marked thus:
+
===== Luminous and non-luminous versions =====
  
:OCTAVA WATCH COMPANY SWITZERLAND/15 FIFTEEN JEWELS/3 THREE ADJUSTMENTS/U.S.A.P. 816321
+
Both luminous and non-luminous versions of the aviation watch were issued from the beginning (although use of the luminous version may have been confined to naval service).  
  
:U.S.A.P. expands to United States Approved Patent.
+
===== Military issue markings =====
 +
*'''Sterile case backs (no markings)'''
  
:Some examples carry both USA and German patent numbers: U.S.A.P. 816321-D.R.P. 175275 (where D.R.P. expands to Deutsches Reich Patent). Sometimes + [PATENT] 33103 is seen as well, denoting a Swiss patent. The extended patent numbers tend to be associated with earlier movements, showing 2 TWO ADJUSTMENTS rather than 3 THREE ADJUSTMENTS. In the aviation watches, it is possible that the variation in marking implies a pre-WWI importation from Europe followed later by importation from the U.S.A. (the U.S.A.P. only marking).
+
:The Admiralty Mark I and Mark II had sterile case backs, apart from one version of the Mark II that was supplied by Thos. Armstrong & Bros, Manchester (which had a unique stamped ‘arrow’ design). Presumably the nomenclature that appeared on the Mark I and Mark II watch dials was considered sufficient for most purposes.
  
:The movement design is protected by a patent for a remontoir winding watch that was filed in the USA on March 23 1905 by Frantisek Hartmann of Prague (then located in the Austro-Hungarian Empire), and issued on March 27 1906. One half of the Patent was assigned to Josef Oliak, who was apprenticed as a watchmaker but later achieved greater fame in his homeland as an actor, especially in films. The subject matter of the patent was <q>''to so arrange the several wheels and other parts of the gearing as to make the winding at relatively long periods possible without increasing the size of the watch, the number of the wheels, and the height of the barrel or spring-box, and retain the center wheel in the middle''</q>. The Swiss Patent (Nr 33103) is dated 11 March 1905, whilst the German patent (D.R.P. Nr 175275) was granted on 22 September 1906.  The documents relating to the US Patent are more widely-quoted, however, because they are more readily available (and are written in English). [[Taylerson]] cites a British Patent Nr 5310 of 15 March 1905, but this Patent doesn’t appear on any of the watch movements seen.
+
*'''A ↑ D dial mark (probably Air Department of the Admiralty) (1912-1915)'''
  
:This is a well known commercial movement, commonly available under the brand name of the Octava Watch Company. This name was registered on 12 April 1907 by ''Graizeley et Cie'', La-Chaux-de-Fonds, Switzerland.  Arthur Graizely had founded ''Graizely Frères'' with his brother in 1888 in order to exploit a patent for an 8-day watch that he had obtained from Irenée Aubry. (This became the well-known ''Hebdomas'' watch, and it was Graizely who developed it into a commercial success). The involvement in the business of Otto Schild of Grenchen led to the company being styled ''Graizeley et Cie'' in 1904 and, from 1915, it became ''Manufacture d`Horlogerie Schild et Cie SA'', based in Rue du Parc, La-Chaux-de-Fonds. The choice of ’Octava’ as a name is intended to indicate a specialism in 8-day watches. Note: the company name is often misquoted as ‘Octavia’.
+
:The A ↑ D mark is painted to the dial of Admiralty Mark I and Mark II watches and probably denotes the Air Department of the Admiralty. This Department existed only for a short time (1912-1915) before it was succeeded by the Air Section (and later the Air Division). ZMW [p 30] prefers ‘Admiralty Department’. The IWM Collection holds a stopwatch made by  S. Smith & Son Ltd that is described as being marked ‘Property of AIR DEP ADMIRALTY’, but no photography is shown.
  
:All Octava movements have serial numbers stamped to the base plate near the balance wheel, allowing broad sequencing to be established.
+
*'''A ↑ S mark (''sui generis'', possibly not an official ‘mark’)'''
  
:The Octava Watch Co supplied movements seen in the Admiralty Marks I and II, the (putative) Mark III, the Mark IVA, and an anomalous version of the Mark V (which otherwise is a 30-hour watch). For a while, Favre-Jacot (better known today as [[Zenith]]) supplied a Mark IVA watch with a movement of this design that was marked with its own BILLODES trademark. (Later examples were marked Octava in the standard manner).
+
:An ‘A ↑ S’ mark appears to the case back of one watch only: the luminous Mark IVA watch supplied by S. Alexander & Son Ltd. The singular use of this mark, combined with the match between the initials used and the name of the supplier (‘Alexander & Son’), argues persuasively for the mark to be regarded as supplier's branding rather than a service designator. ZMW [p 12] attributes this mark to the Royal Naval Air Service c. 1914 (‘Air Service’), however.
  
'''Unmarked Swiss gilt-finished 8-day movement'''
+
*'''W ↑ D mark (War Department) (up to 1917)'''
  
:Swiss 8 Day movement with straight line lever escapement and compensated balance.
+
:The War Department (W.D.) mark (W ↑ D) was applied to the Mark IVA watch until that mark was cancelled in 1917. (See RAF Form 1048 ref: 2000/10/17, shown in KK [p 395]). At least two different designs were employed: an elaborate decorated version that occupied the whole of the flat portion of the case back; and a much smaller, simple, stamped version that is the more common usage seen in surviving examples.
  
:The lack of markings means that neither the manufacturer nor the calibre has yet been identified, although all dials have ‘Swiss Made’ to them, so we can assume a Swiss movement.
+
:Although the War Department became the War Office in 1857, the name remained in use for certain purposes.
  
:Serial numbers are stamped clearly to the main movement plate in a standard fashion, allowing broad sequencing to be discerned.
+
*'''‘Air’ mark (possibly Air Board) (1917 onwards)'''
  
:This movement is seen only in the Mark IVA watch.  
+
:The ‘Air’ Mark (A [underline] Broad Arrow] was applied to all Mark V watches (and to a very late version of the H. Williamson Ltd Mark IVA: see RAF Form 1048 ref: 2000/10/17, shown in KK [p 395], which specifies the small 9/32 x 3/16 inch version that was only seen on this watch). The use of this mark may reflect the reorganisation of war effort that led to the creation of the Air Board in 1917. However, ZMW [p 12] prefers ‘Aviation’.
  
'''(Eterna) Swiss gilt-finished 8-day movement'''
+
*'''Air Ministry mark (inter-war)'''
  
:Swiss 8 Day movement with straight line lever escapement and compensated balance.
+
:The Air Ministry mark (A.M. with King’s Crown surmounted), which was used from the inter-war period until c 1944, occasionally appears in addition to one of the other marks, indicating retention in stores after WWI. These watches sometimes have ‘G.S. Type’ applied to the dial, indicating a General Service watch that in RAF usage was assigned the 6E/50 stores reference. (I have seen one Mark V watch with 6E/50 and the A.M. mark applied to the case back).
  
:This distinctive movement has been seen in watches marketed under the [[Eterna]] trademark.
+
=====Eight-day movements=====
  
:Serial numbers are stamped to the base plate of the movement, allowing broad sequencing to be established.
+
Before the 30-hour Mark V standard was formulated, the British aviation watch used 8-day movements from a variety of Swiss makers (not all of them identified). It is likely that 8-day movements were chosen for their inherent stability and accuracy rather than in anticipation of extended flying times. It was probably not until manufacturers could prove that 30 hour movements matched that requirement that the Mark V was specified and produced. (That is to say, the later adoption of the 30-hour watch reflects the evolution of Swiss watchmaking rather than a change in military requirements).
  
:This movement was supplied uniquely by H Williamson for the Admiralty Mark II and Mark IVA watches. The movement is entirely different to the 7-jewel Astral movement that Williamson used for its General Service watches supplied to the British Army during WWI.
+
'''Octava Watch Company 8-day movement'''
  
'''Douard Patent Swiss gilt-finished 8-day movement'''
+
:The Octava Watch Co supplied movements seen in the Admiralty Marks I and II, the (putative) Mark III, the Mark IVA, and an anomalous version of the Mark V (which otherwise is a 30-hour watch). For a while, Favre-Jacot (better known today as [[Zenith]]) supplied a Mark IVA watch with a movement of this design that was marked with its own BILLODES trademark. (Later examples were marked Octava in the standard manner).
  
:Swiss 8 Day movement with straight line lever escapement and compensated balance.
+
:All Octava movements have serial numbers stamped to the base plate near the balance wheel, allowing broad sequencing to be established.
  
:The main movement plate has +7032 stamped to its edge. This denotes a Swiss patent for a new design of 8-day watch calibre (<q>''nouveau calibre de montre a huit jours de marche''</q>) granted on 19 July 1893 to Amédée Douard (pere) of Bienne, Switzerland. The patent claims a novel combination and arrangement of cogs in an 8-day watch movement.
+
'''Unmarked Swiss gilt-finished 8-day movement'''
  
:The movements have serial numbers stamped to the dial face of the base plate, which is usually inaccessible.
+
:Serial numbers are stamped clearly to the main movement plate in a standard fashion, allowing broad sequencing to be discerned.
  
:This movement was used by [[Smiths]] to supply Admiralty Mark II watches.
+
:This movement is seen only in the Mark IVA watch.  
  
=====Nomenclature to the dial=====
+
'''(Eterna) Swiss gilt-finished 8-day movement'''
  
The dials carried as a minimum the name of the supplier and the spec that it fulfilled (eg Mark IVA). Individual serial numbers came to be applied later and most incorporated a letter code that identified the supplier. This letter code was superfluous where the supplier's name was written in full above the number but it was standard practice to mark all military equipment of the era in this way. The Mark V watches did not in fact carry manufacturer’s names to the dial, although branding did appear to the movements and/or cuvette and/or inner case back.
+
:This movement was supplied uniquely by H Williamson for the Admiralty Mark II and Mark IVA watches. The movement is entirely different to the 7-jewel Astral movement that Williamson used for its General Service watches supplied to the British Army during WWI.
  
===== Military issue markings =====
+
:Serial numbers are stamped to the base plate of the movement, allowing broad sequencing to be established.
*'''Sterile case backs (no markings)'''
 
  
:The Admiralty Mark I and Mark II had sterile case backs, apart from one version of the Mark II that was supplied by Thos. Armstrong & Bros, Manchester (which had a unique stamped ‘arrow’ design). Presumably the nomenclature that appeared on the Mark I and Mark II watch dials was considered sufficient for most purposes.
+
'''Douard Patent Swiss gilt-finished 8-day movement'''
  
*'''A ↑ D dial mark (probably Air Department of the Admiralty) (1912-1915)'''
+
:This movement was used by [[Smiths]] to supply Admiralty Mark II watches.
  
:The A ↑ D mark is painted to the dial of Admiralty Mark I and Mark II watches and probably denotes the Air Department of the Admiralty. This Department existed only for a short time (1912-1915) before it was succeeded by the Air Section (and later the Air Division). ZMW [p 30] prefers ‘Admiralty Department’. The IWM Collection holds a  stopwatch made by  S. Smith & Son Ltd that is described as being marked ‘Property of AIR DEP ADMIRALTY’, but no photography is shown.
+
:The movements have serial numbers stamped to the dial face of the base plate, which is usually inaccessible.
 
 
*'''A ↑ S mark (''sui generis'', possibly not an official ‘mark’)'''
 
 
 
:An ‘A ↑ S’ mark appears to the case back of one watch only (and so can be considered ''sui generis''): the luminous Mark IVA watch supplied by S. Alexander & Son Ltd. ZMW [p 12] attributes this mark to the Royal Naval Air Service c. 1914 (‘Air Service’). However, the fact that this mark’s appearance is limited to one anomalous watch, combined with the match between the initials used and the name of the supplier (‘Alexander & Son’), makes it more likely to be supplier's branding than a single-use official mark.
 
 
 
*'''W ↑ D mark (War Department) (up to 1917)'''
 
 
 
:The War Department (W.D.) mark (W ↑ D) was applied to the Mark IVA watch until that mark was cancelled in 1917. (See RAF Form 1048 ref: 2000/10/17, shown in KK [p 395]). At least two designs were employed: an elaborate decorated version that occupied the whole of the flat portion of the case back; and a much smaller, simple, stamped version that is seen much more commonly.
 
 
 
:Although the War Department became the War Office in 1857, the name remained in use for certain purposes.
 
 
 
*'''‘Air’ mark (possibly Air Board) (1917 onwards)'''
 
 
 
:The ‘Air’ Mark (A [underline] Broad Arrow] was applied to all Mark V watches (and to a very late version of the H. Williamson Ltd Mark IVA: see RAF Form 1048 ref: 2000/10/17, shown in KK [p 395], which specifies the small 9/32 x 3/16 inch version that was only seen on this watch). The use of this mark may reflect the reorganisation of war effort that led to the creation of the Air Board in 1917. However, ZMW [p 12] prefers ‘Aviation’.
 
 
 
*'''Air Ministry mark (inter-war)'''
 
 
 
:The Air Ministry mark (A.M. with King’s Crown surmounted), which was used from the inter-war period until c 1944, occasionally appears in addition to one of the other marks, indicating retention in stores after WWI. These watches sometimes have ‘G.S. Type’ applied to the dial, indicating a General Service watch that in RAF usage was assigned the 6E/50 stores reference. (I have seen one Mark V watch with 6E/50 and the A.M. mark applied to the case back).
 
 
 
===== Luminous and non-luminous versions =====
 
 
 
Both luminous and non-luminous versions of the aviation watch were issued from the beginning.
 
  
 
==== ''The Admiralty Mark I'' ====
 
==== ''The Admiralty Mark I'' ====

Revision as of 13:45, 9 April 2020

Notes on British Military Watches 1914-1919

References

  • Konrad Knirim British Military Timepieces/Uhren der britischen Streitkräfte (POMP, 2009) (‘KK’)
  • A Taylerson Military Timepieces: Watches Issued to British Armed Forces 1870-1970 (Horological Journal September 1995 pp 293-296; October 1995 pp 334-337) (British Horological Institute,1995) (‘Taylerson’)
  • Z. M. Wesolowski A Concise Guide to Military Timepieces 1880-1990 (The Crowood Press, 1996) (‘ZMW’) .

British Watches, Aircraft


Historical Background

Britain was notoriously slow to adopt powered flight. The first flight in Britain of a heavier-than-air, manned, craft was not recorded until 16 October 1908. (The pilot was Samuel F Cody, an American, assisted in his efforts by the Royal Engineers based in the ‘Balloon Factory’ at Farnborough). The Royal Flying Corps (RFC) was established in April 1912, however, and soon afterwards the recently-formed Air Battalion of the Royal Engineers, its observation kites and balloons now supplemented by fixed wing aircraft, was surrendered to provide the basis for the Military Wing. The Naval Wing of the RFC, administered by the Air Department of the Admiralty (1912-1915), quickly evolved into the Royal Naval Air Service (RNAS), which was part of the Military Branch of the Royal Navy, and under the control of the Admiralty from 1914 onwards.

This separation of air power, which was never clear cut or even necessarily intuitive, continued throughout the war, with both organisations often competing for the same resources. The RNAS operated seaplanes from bases such as Calshot in Hampshire and Eastchurch in Kent, and pioneered the flying of aircraft from naval vessels. However, the Admiralty also sent land-based aircraft to France in support of RFC operations and interpreted its historical role as defender of the island’s coastline so liberally at times as to include responsibility for the air defence of Great Britain and to justify attacks on Zeppelin bases and manufacturing sites located in Germany.

On 1 April 1918, the Royal Air Force was established as an ‘independent’ force, ie as a third arm, separate from both the Army and the Navy, and the RFC and RNAS were both disbanded.

The working assumption among military watch collectors has always been that the RNAS issued the Admiralty Type I and II aviation watch throughout WWI whilst the RFC issued the Mark IVA, and later the Mark V.

Common Features of the WWI Aviation Watch

The archetype for British aviation watches was established from the start:

  • nomenclature was applied to the dial (specifying, amongst other things, the contracted supplier of the watch)
  • both luminous and non-luminous versions of the watch were issued
  • markings were applied to the case to indicate military issue (except in the Admiralty Marks)
  • an 8-day Swiss movement was used for the works (even in the Mark V, which allowed otherwise for 30-hour movements)
Nomenclature to the dial

The dials carried as a minimum the name of the supplier and the spec that it was intended to address (eg Mark IVA).

Individual serial numbers came to be applied later and most incorporated a letter code that identified the supplier. It was British standard practice during WWI to mark military equipment supplied under contract in this way.

The Mark V watches did not carry manufacturer’s names to the dial, but they are identified by their digraphic letter codes (and branding did appear to the movements, cuvette, inner case back, etc).

Luminous and non-luminous versions

Both luminous and non-luminous versions of the aviation watch were issued from the beginning (although use of the luminous version may have been confined to naval service).

Military issue markings
  • Sterile case backs (no markings)
The Admiralty Mark I and Mark II had sterile case backs, apart from one version of the Mark II that was supplied by Thos. Armstrong & Bros, Manchester (which had a unique stamped ‘arrow’ design). Presumably the nomenclature that appeared on the Mark I and Mark II watch dials was considered sufficient for most purposes.
  • A ↑ D dial mark (probably Air Department of the Admiralty) (1912-1915)
The A ↑ D mark is painted to the dial of Admiralty Mark I and Mark II watches and probably denotes the Air Department of the Admiralty. This Department existed only for a short time (1912-1915) before it was succeeded by the Air Section (and later the Air Division). ZMW [p 30] prefers ‘Admiralty Department’. The IWM Collection holds a stopwatch made by S. Smith & Son Ltd that is described as being marked ‘Property of AIR DEP ADMIRALTY’, but no photography is shown.
  • A ↑ S mark (sui generis, possibly not an official ‘mark’)
An ‘A ↑ S’ mark appears to the case back of one watch only: the luminous Mark IVA watch supplied by S. Alexander & Son Ltd. The singular use of this mark, combined with the match between the initials used and the name of the supplier (‘Alexander & Son’), argues persuasively for the mark to be regarded as supplier's branding rather than a service designator. ZMW [p 12] attributes this mark to the Royal Naval Air Service c. 1914 (‘Air Service’), however.
  • W ↑ D mark (War Department) (up to 1917)
The War Department (W.D.) mark (W ↑ D) was applied to the Mark IVA watch until that mark was cancelled in 1917. (See RAF Form 1048 ref: 2000/10/17, shown in KK [p 395]). At least two different designs were employed: an elaborate decorated version that occupied the whole of the flat portion of the case back; and a much smaller, simple, stamped version that is the more common usage seen in surviving examples.
Although the War Department became the War Office in 1857, the name remained in use for certain purposes.
  • ‘Air’ mark (possibly Air Board) (1917 onwards)
The ‘Air’ Mark (A [underline] Broad Arrow] was applied to all Mark V watches (and to a very late version of the H. Williamson Ltd Mark IVA: see RAF Form 1048 ref: 2000/10/17, shown in KK [p 395], which specifies the small 9/32 x 3/16 inch version that was only seen on this watch). The use of this mark may reflect the reorganisation of war effort that led to the creation of the Air Board in 1917. However, ZMW [p 12] prefers ‘Aviation’.
  • Air Ministry mark (inter-war)
The Air Ministry mark (A.M. with King’s Crown surmounted), which was used from the inter-war period until c 1944, occasionally appears in addition to one of the other marks, indicating retention in stores after WWI. These watches sometimes have ‘G.S. Type’ applied to the dial, indicating a General Service watch that in RAF usage was assigned the 6E/50 stores reference. (I have seen one Mark V watch with 6E/50 and the A.M. mark applied to the case back).
Eight-day movements

Before the 30-hour Mark V standard was formulated, the British aviation watch used 8-day movements from a variety of Swiss makers (not all of them identified). It is likely that 8-day movements were chosen for their inherent stability and accuracy rather than in anticipation of extended flying times. It was probably not until manufacturers could prove that 30 hour movements matched that requirement that the Mark V was specified and produced. (That is to say, the later adoption of the 30-hour watch reflects the evolution of Swiss watchmaking rather than a change in military requirements).

Octava Watch Company 8-day movement

The Octava Watch Co supplied movements seen in the Admiralty Marks I and II, the (putative) Mark III, the Mark IVA, and an anomalous version of the Mark V (which otherwise is a 30-hour watch). For a while, Favre-Jacot (better known today as Zenith) supplied a Mark IVA watch with a movement of this design that was marked with its own BILLODES trademark. (Later examples were marked Octava in the standard manner).
All Octava movements have serial numbers stamped to the base plate near the balance wheel, allowing broad sequencing to be established.

Unmarked Swiss gilt-finished 8-day movement

Serial numbers are stamped clearly to the main movement plate in a standard fashion, allowing broad sequencing to be discerned.
This movement is seen only in the Mark IVA watch.

(Eterna) Swiss gilt-finished 8-day movement

This movement was supplied uniquely by H Williamson for the Admiralty Mark II and Mark IVA watches. The movement is entirely different to the 7-jewel Astral movement that Williamson used for its General Service watches supplied to the British Army during WWI.
Serial numbers are stamped to the base plate of the movement, allowing broad sequencing to be established.

Douard Patent Swiss gilt-finished 8-day movement

This movement was used by Smiths to supply Admiralty Mark II watches.
The movements have serial numbers stamped to the dial face of the base plate, which is usually inaccessible.

The Admiralty Mark I

The Admiralty Mark II

The Mark III (putative)

The Mark IVA

The Mark V

British Watches, Pocket General Service


For most of WWI, the standard British military issue was a 7 jewel pocket watch, supplied by established firms like H Williamson, H White, and W Ehrhardt. All but the Ehrhardt were cased by Dennison (Ehrhardt being an established case maker in its own right).

Once the USA came on board, 7 jewel Elgin pocket watches were supplied also, c 1917.

Watches issued to the Royal Artillery need to be considered separately because they were entirely different (eg some hacked).

A Corporal of the Border Regiment wounded in the Somme battles of July 1916 mentions his issued pocket watch in an IWM interview: I can remember an RAMC man looking at me and saying: 'He won't live long...' and he took my watch out of my breast pocket - my official watch, suspended on a leather strap. Royal Army Medical Corps? Royal Army Robbing Corps more like!. To be fair to the maligned, removal of valuable officially issued items may have been a standing order in those circumstances.

British Watches, Wristlet


The starting point

Some trench watches bear the unmistakable signs of issue to the British Armed Forces: a broad arrow marking and/or an engraved alphanumeric sequence (an ‘issue number’). Genuine examples of these watches are rare, and reliable information about them scarce.

The starting point for most discussions of WWI British military-issued wristlets is ZMW [p 60]. This short but troublesome text states that:

  • the British War Department obtained wristlets c 1917 for evaluation and issue (hence some collectors know these as 1917 evaluation watches);
  • the watch dials used were black enamel with radium-filled numerals and hands;
  • a number of different unsigned Swiss lever 15 jewel movements were employed;
  • two designs of case were used: snapback and screw back;
  • the snapback watches proved unsuitable in the field and were disposed of, whereas the screw back watches proved themselves and were retained.

Although I would challenge the first and last of these statements, a neat scheme is suggested whereby issued wristlets can be categorised according to whether their cases were of a snapback or screw back design, viz.

  • the 38mm snap back;
  • the various Dennison cased screw-back watches (3 distinct types).