The Seiko Silverwave Cockpit – 2628-0040



In 1981 the Seiko Silverwave 2628-0040 won the Japanese Good Design award from the Ministry of International Trade and Industry,  for this, the first cockpit watch.

It was produced in 1981 and is equipped with a quartz movement.

This watch is the first cockpit instrument styled wristwatch ever produced. It measures 34mm square, with the crown, is 37mm across and is 8mm thick. Lug to lug measures 40mm and lug width is 22mm, which complements the design.

The watch is powered by a small 2-jewel Cal. 2628A hacking quartz movement that runs at 32,768 Hz. The dial below features a blue sunburst finish with a small seconds sub-dial at the 6 o’clock position. This is contrasted by legible Arabic numeral fonts with single heavy ticks at the hour markers and an easy to see double tick at the 12 o’clock mark. Sword style hour and minute hands compliment the fonts quite nicely.

The face of the watch has 4 “mounting” screws, and a black rubberised finish, just as cockpit instruments are similarly finished to minimise reflection.


2628-0040: Seiko Silverwave Cockpit

The green version was PEQ012 and the dark navy blue PEQ011 in the Seiko numbering system of the time.

2628 green: Seiko Silverwave Cockpit

The 2628A movement was quite small, and needed spacers to fit the square housing.

2628A cal: Seiko Silverwave Cockpit

The case back featured the classic Silverwave tsunami logo, but it is only labelled water-resistant.


Production lasted from 1981 to 1983, and then ceased.

This article covers just this watch, in order to cement it’s place as the first cockpit watch.


The beginning of Trintec was in 1984 when Brendon Nunes commenced making a clock that was inspired by an aircraft altimeter.   He went on to patent the clock, and in 1990 commenced making a derivative watch, the 9060 Altimeter Watch.

Trintec: Seiko Silverwave Cockpit


The watch in 1990 had a Miyota quartz movement and it had the same design elements like the clock.  The first batch of 200 was used as a promo tool within Ryder Aviall, which is one of the world’s largest aviation parts distribution companies.

Similarities to the Seiko 2628-0040 are obvious, as they drew their inspiration from the same sources.   There is a 33mm black square case, black dial, sword hands, clearly legible dial and 4 mounting screws.

Seiko Silverwave Cockpit


Carlos Rosillo and Bruno Belamich founded Bell & Ross in about 1994.

Initially, Bell & Ross watches were designed by the duo and built by Sinn. An example of these Bell & Ross by SINN watches is shown below.

This watch is a SINN model 156 with the classic Lemania 5100  automatic chronograph classic multi-function analog movement.

The collaboration ended in 2002.

Bell and ross by Sinn: Seiko Silverwave Cockpit

In 2005 Bell & Ross released the BR-01, which again resembles the above watches which drew their inspiration from the cockpit.  Again the design elements of black square case, black dial, sword hands and 4 mounting screws are present.

The watch is 47mm square.

b&R 01-92: Seiko Silverwave Cockpit


The Seiko cockpit watch predates the others by 10 and 25 years respectively.

The Rotating Bezel Invented by Weems- the Rotary Verge Ring


The question has been asked “Which watch carried the first rotating bezel?”

The answer is the Weems, with what the advertising initially called a rotary verge ring.

The model featured above is from about 1930.  It is the design drawing for Longines serial number 5145705 with Breguet hands, and is related to his patent application of 1929 which encompassed a rotating bezel.

Perhaps a distant second is the 32mm diameter Rolex Zerographe ref. 3346 which also featured a rotating  bezel, but this dates to 1937, and was never made available for public sale.

A possible even more distant third is the Glycine Airman patent 314050 of 1953, registering a rotating 24 hour bezel and a bezel lock at 4 o’clock.



This article will discuss the development of the Weems rotating bezel up to about 1940 when the military versions of the second setting watch were introduced.


Modern air navigation is strongly influenced by the work of Philip Van Horn Weems, who worked on all aspects of what was then called avigation.

In the middle 1920’s pilots were being killed crossing the oceans, as avigation was not easy, so Weems expanded his naval experience to the needs of pilots.

By the early 1940’s the Weems System of Navigation course trained many military aviation navigators, and marine navigators, using the books and equipment that Weems had developed and used earlier for commercial navigation.

Weems determined that it was essential to simplify aviation navigation computations, and to develop fast, reliable methods of navigation that were simpler than maritime techniques, even if slightly less accurate.

Although radio beacon navigation improved rapidly in the 1930’s, this was rendered marginally operable in WW2, and onboard navigation computations using Weems systems were necessary for most of the WW2 period.




A vital stepping stone in advancing both marine and air navigation was the Weems Second Setting watch.

Weems decided that it would be sufficiently accurate to avigate with a good quality watch which could be easily reset to radio time signals, rather than attempt to carry a delicate marine chronometer in the air.


In 1927 the US navy started converting surplus war stock patrol boat chronometers to accept his simple modification to develop a “hack” watch.

Lieutenant Commander P.V.H. Weems, U.S. Navy,  June 1928 issue of Proceedings USNI Magazine wrote :


“The first two Weems watches were torpedo boat watches one Hamilton rated to mean time and a Patek Philippe & Cie. watch rated to sidereal time. They were altered to permit the exact second to be set. The details of altering these watches was worked out with Mr. Dadisman, the best mechanic at J. Jessops and sons San Diego. A slightly different alteration was made on the watches, since they are not similar in construction. In each case the second dial was cut out, and a movable dial mounted on a ratchet wheel with sixty teeth was inserted. A small arm,on the left side of the watch,operated by the finger nail moves the dial from one to three seconds per stroke,making it a simple matter to set the exact second. The hour and minutes are set in the usual manner.”

The article continues :

“Mr. Lincoln Ellsworth, the polar explorer, has the Number One commercial second-second setting watch, designated by Jessops as the “Aero Chronometer”.

These watches were initially converted in larger numbers by Louis Levin and Sons in California, but later in house by the Navy.

Below is a Weems Aero-chronometer, adjusted 27 November 1928 by Louis Levin, with an adjustable second setting dial at 6 o’clock, and a power reserve indicator at 12 o’clock.   Waltham Vanguard pocket watch, dial marked Weems Pat. Pending.

Weems seconds settingWeems seconds setting

Below is an earlier model without the patent pending addition to the dial.

Another Vanguard conversion with the second setting at 1 o’clock, with an article from a Motor Boating magazine.

Most aviators in the mid to late 1920’s operated on the margins of the aeronautical industry, which prized aerodynamic and propulsive innovations above all else. For instance, when Charles Lindbergh sought to win the Orteig Prize by flying from New York to Paris in 1927, his primary interest was finding the right airframe and engine combination, with navigation as an afterthought.

After Charles Lindburgh successfully flew the Atlantic as a solo pilot, with a combination of luck, and dead reckoning, he realised that he needed navigation (avigation) training.  

 Weems taught him avigation in 1928, and can be seen below with a chronometer on his left forearm.


After the two men met in 1928, Weems gave Lindbergh one of his second setting watches and taught him how to use it.  The Navy assigned Weems to teach Lindbergh celestial navigation, which differs from traditional navigation because the movement of the stars is slightly different than that of the sun. The watch measured celestial time, or sidereal time, so that airplane navigators didn’t have to work out corrections mathematically. Instead, they could just check the time on their wrist.

Weems lindburgh

Above, Waltham Vanguard pocket watch with Weems second setting facility, and wind up indicator, below, case back engraved Lindburgh.


The second setting modification allowed navigation watches to be “hacked” (or set via radio signal tone) to the exact second, which eliminated a small, but cumbersome, navigation computation.   This was done by revolving an internal seconds disk to coincide with the exact time using a second crown on the watch.

Weem’s personal second setting watch was such an important development that it is on exhibition at the Smithsonian Institute, as shown below.


The deck watch was too large for pilots, and the A-3 wrist watch second setting version was produced between 1928 and 1936 by Longines and Longines Wittnauer.   The A-3 model was largely produced by Longines, and has the central seconds button protected by tapered shoulders.  The A-12 model, from 1936 to about 1946 had the central seconds winder protected by two steel shoulders.

The model below is the A-12 model, but it belonged to Weems.   This watch shows Sidereal Time.

Smithsonian Institute Exhibit of PVH Weems personal seconds setting watch.


Production of the A-3 watch ran until about 1936 and a similar model, the A-12, was produced from 1936 to 1946.

Below is a commercially available model, serial number 4931599 of 1928.

The A-3  watch is heavily influenced by Breguet design features, and is about 47mm diameter, and has an internal rotating seconds setting dial insert.  The central seconds setting is operated by pressing the button below the crown, and simultaneously rotating the crown.

Weems worked initially with Longines/Wittnauer who patented the design in 1929.  Longines in 2007 made a homage version of this watch to celebrate the 80th anniversary of the Weems Second-Setting Watch.   Model L2.713.4.11.0 with automatic at 6 betraying the homage.

The navigation watch, second setting, standard model, A-12,  in about 1940 sold for $80

The early models below are just signed Longines.

Longines model serial number 4931593 of 1928, with a serial number 6 different from the watch above.

1929 model, serial number 5044000 below.

And, a closely related serial number 5044085,  above.



Above is Longines serial number 5167806 of 1931 with roman numerals and large sliding lever/clamp.


A nice counterbalanced second hand on the model below.

A variety of dials exist, with later models from about 1936 signed Wittnauer at 12 and Longines at 6.

In 1936 A. Wittnauer was sold to Hella Deltah, a pearl manufacturer. Capitalising on the long partnership and history with Longines, the company was renamed Longines-Wittnauer.

A-12 model below, with steel protection for the central seconds winder, which is now an independent crown at 4 o’clock.



Serial number 5941864 from 1940 below.


And a slightly later serial number 5942315 also from 1940 below.



A series of the A-3 watch was made for the Japanese Imperial Navy between 1936 – 1946 (IJNAS).  The one below has had lume added at 12 and to the hands.

Model 5320586 was one such watch supplied to the Japanese Air Force.
Two watches in the Longines museum, a 12 and 24 hour model.
Second setting watches in the Longines museum.  Image courtesy MWR Forum user : Syrte.
A rare 24 hour second setting standard model, on exhibition in the Longines Museum.
A black dial A-3 model from 1935.    Anti magnetic on dial at 6 o’clock.
This watch did not have fixed bars, and has cathedral hands.   It also has a rotating bezel with a coin edge.
The model below has a larger triangle pointer at 12 o’clock.
These models were sold into Europe.


Production continued until after the war and below is an A-12 model from 1948, serial number 7,298,483


This book taught avigation, and discussed the standard second setting watch, and the later, smaller wrist watch.

Weems : Air Navigation pages 299 to 304
Text on the second setting watch.




The early wrist model Weems on the right does not have a bezel lock.

The 1935 promotional film, US Army Air Corps, Avigation Training, from Rockwell Field, North Island San Diego, featured a navigator wearing a Standard Second Setting watch.

 And then taking a sun shot.


The wrist second setting model was much smaller at 27mm diameter, and appeared in about 1930.   This watch had the first external rotating bezel, and was simpler to operate and much more robust than the standard model.

Several of these prototype watches were made by Harry Nash in Jessop’s Jewellery shop in San Diego, before turning the model over to Longines for quantity production.

The early model featured a rotary verge ring, which was not locked into place.  This quickly was found to be deficient, and was then locked in place by a cam lock on the lugs at 6 o’clock.     Below is a design drawing for serial number 5145705 with Breguet hands.  This  dates the watch to about 1930.


An advertisement for this cam lock model, D below, describes a moveable bezel.


US Naval Academy bottom lock watch, above.   Image courtesy MWR Forum user : rojda

Another photo of the same dial below, on a different strap.

Serial number 5404101 of 1936/7, modified Cal. 11L movement.

Weems bottom lock

Image courtesy Omega Forum user : DirtyDozen12

The watches were sold officially to the midshipmen at the US Naval Academy.

This watch has the same clamping mechanism in the figure below.

A non US navy model is shown below, missing the sweep second hand.


Although rare on a Weems second setting watch, the bottom clamp is more common on the 33mm diameter Longines Lindbergh hour angle watch of about 1936 to 1947 (e.g. movement 7320132 cal 12L).  The crown at 2 o’clock was necessary to rotate the seconds setting  dial at the centre of the watch, so another clamp position was needed.  This 33mm Longines Lindbergh watch is not discussed in detail in this article.


Later Weems models featured a bezel lock at 2 o’clock.

In February 1934 President Roosevelt charged the Air Corps with the responsibility for delivering the U.S. mail, a service previously provided by commercial carriers.

During the 78-day Air Corps mail operation, military pilots flew on badly equipped aircraft over unfamiliar routes during one of the worst winters on record. The loss
of life was staggering. In 66 crashes, 12 pilots died. The Air Corps had been unable to equip its planes, most of which were seriously out of date, with the latest navigational aids. Most pilots had not trained in blind flying, were unfamiliar with the expensive new radio equipment, and had flown only during the daytime and in decent weather.  The need for instrument training in the USAAC was obvious.

Weems responded to this in early 1935 by providing 200 wrist watches to the military for evaluation.  Of these 100 went to the 17th Pursuit Group and 100 went to the 7th Bombardment Group.

The GHQ Air Force training directive for 1938-9 required that navigators be qualified to establish position in the air by celestial means to within 25 miles.

The Army also commenced ordering the Link Trainer, patented in 1931 by Edwin A Link.

Popular Aviation December 1937, indicates the model, signed just Longines, would be ideal for camera enthusiasts, sportsmen, doctors, nurses, and numerous others.


Aviation, November 1937, has wrist model, with the bezel clamp at 4 o’clock.


A Naval Academy version serial number 5,4xx,xxx is shown below.  This is a 33mm model, from about 1937.   Modified Cal 11L movement.

Weems 33mm

Image courtesy Omega Forum user : Seiji

This Longines signed model from about 1937 has applied Breguet numbers, and stick hands, but leaf hands were also used.


The case back is engraved around the outside : LONGINES WEEMS SECOND SETTING WATCH. INVENTED BY LT COM.PVH WEEMS USN.

This case and 27mm watch is in a Longines advertisement featured in the Time and Navigation section of the Smithsonian Museum.

By late 1937 a second larger 33mm watch appeared.  The identical case below has a 1938 33mm Longines Weems watch with the 12L calibre 17J movement on an original strap, serial number 5769542.

A later Air Navigation book showed a 34mm diameter watch with a bezel lock at 4 o’clock, as in the 1937 article above.

Serial number 5736820 late 1937 watch with locking crown at 4 o’clock, diameter about 33mm, 15J movement with spacer ring.   The hands are blue leaf, and the dial carries US Airforce pilot wings.   Plain push back.

Image courtesy MWR forum member : T5AUS

The 1939 model below used the Cal 10.68N movement, signed Longines Weems. Plain push in case back.


This model still has applied indices in gold, and leaf hands.  Signed Longines.

A 1938 model, serial number 5840053 is shown below, signed Longines Weems.


For the commercial pilot, there was the gold filled model with Breguet indices.


The more expensive gold filled model above, with applied gold indices.

A model with baton indices.

A stick hand model with serial number 6525779 from 1943.

Below is a collage of these 27mm models, some dating into WW2 (with radium hands), to illustrate the variety of dials.

Image courtesy MWR forum user : flightpath


In 1937 the US Air Corps commenced looking at hackable watches.  The relevant military specification was the 27834 specification.

The earliest A-11 watches were the Longines Weems model watches, which were tested beginning in 1937 prior to the standardisation of the A-11 in May, 1940.

The Type A-11 white dialed Weems models were produced by Longines-Wittnauer under the 27834 specification.   The Weems watches had a movable numbered bezel to synchronize the time to the radio time signal or “hack”, rather than the later A-11 Elgin sweep second hand with a “hacking” feature, which stopped the second hand when the crown was pulled out. In the Weems A-11, the bezel is rotated in synchronization with the second hand until the time hack is heard, at which point the small screw “stop” is tightened down.  [See Whitney’s Military Timepieces.]

The watch below has a possible early A-11 case back.  This is serial number 5938466, the earliest known in the series.   The later case back has Case serial number 40 – xxx (and much more) engraved, but movement serial numbers overlap.

The Weems movement was a 10.68N, or an identical 10L

All these watches had U.S. ARMY A.C. on the movement.



There has been some discussion about the authenticity of the watches with this engraving on the case back, as they should read U.S.A.A.C., but several are known to exist, with early serial numbers.

However, after possible prototypes, when the production commenced in earnest, it was a sterile dial with blued propellor hands, and full Mil Spec details on the case back as shown below.

A 1940 Longines-Wittnuer Weems A-11 is shown below.  The diameter is 27.5mm, and the smaller dial has no seconds markers as did the Elgin A-11, but the hands are the same as the Elgin A-11 model.    There are seconds markers on the bezel, and 2 circular rings on the dial, not seen on other models.

Longines –  Wittnauer 1940 Weems A-11.
Made to Mil Spec 27834.
Some of these watches do not have sterile dials, and the model number has been seen up to Case Serial No. 40 – 1075.


Marked U.S. ARMY A.C. on the movement.

A rare signed version above Serial No 5938584 but case Serial number 40-502.

With the advent of the 1940 military version of the 27mm Weems,  the first watch with a rotating bezel, we will conclude our discussion of the pre war watches.

At the same time as the US Army Air Corps was looking at the 27mm diameter Weems watch, the larger 33mm watch was of interest to the RAF.

This Antiquorum image is of a 34mm diameter model, with blued spade hands, and red sweep second hands, serial number 5940884 from about 1939, strikingly similar to the RAF 6B/159.


The larger 34mm model became the basis of the British military watch.

We will discuss this in another article.

Below we continue the discussion on Weems the avigator.


Before 1927, watches used with sextants for celestial sightings could only be set to the minute.   A watch error of 30 seconds could cause a navigational error of up to 12 kilometers.  In 1927,  Weems devised a watch with an adjustable second disc that could be set to match radio time signals.

This watch exhibited above in the Smithsonian Institute was one of his personal navigation watches. Sidereal time on the dial refers to the watch running on a celestial day (about 23 hours, 56 minutes), rather than the 24 hour solar day.

Weems worked both on the time aspect of aviation navigation, and the celestial sighting aspects.

A marine navigator in the relatively spacious confines of a vessel could compute a position fix in fifteen minutes, but an aviator in an open cockpit faced a different set of conditions. The cold air at altitude with relative wind speeds near 160 kph, combined with gloved hands and incessant noise and vibration, made position fixing an unreliable and often impossible task in early long-range airplanes.

Maritime celestial techniques proved inadequate for aircraft.  One limitation was speed.  Lengthy computations meant longer times possibly flying incorrect headings, resulting in greater positional errors.  Aircraft instability made celestial sightings inaccurate.  Weather also posed numerous problems, ranging from moving horizons to turbulence.  Last, the cockpit environment was hostile to the process of navigational computations.

Weems determined that it was essential to simplify aeronautical navigation computations, and to develop fast, reliable methods of navigation that were simpler than maritime techniques, even if slightly less accurate.



Weems also developed this simple but effective plotter for aeronautical charts in 1935. It still remains the most popular aviation plotter in the United States.

Along with this and his improved watch, discussed above, Weems also developed and published his Line of Position Book, which repackaged existing star sight tables developed by Shinkichi Ogura in Japan and Armistead Rust, a fellow naval officer,  into a more user friendly format.  His “Star Altitude Curves” provided quick graphical solutions for bubble sextant sightings.  Eventually this became the “Air Almanac”.


This book of graphical solutions provided nighttime celestial calculations five times faster than other techniques. It required the sighting of Polaris and at least one other well-known navigational star.

Weems also aided development of an improved Bausch and Lomb aeronautical bubble sextant. Taken together, Weems’s innovations, packaged as the “Weems System of Navigation,” greatly reduced the time required for navigation computations.


Weems book, “Air Navigation” (1931),  was particularly well received, and was awarded a gold medal by the Aero Club of France.


Weems worked on many aspects of navigation, and his patent below for an improved watch was primarily for elimination of chronometer errors with a dual drive, but the second setting watch was much simpler, and was routinely employed by 1929.   But, the patent is for a complex rotating bezel, the first such design for a watch.


Weems patent application of 1929.



In the late 1930s, with war imminent, Great Britain approached Edwin A Link with a request that he design a version of his trainer to more quickly and easily teach celestial navigation to RAF crews – the CNT.   Weems collaborated with Ed Link on the Celestial Navigation Trainer, and together they wrote a book, “Simplified Celestial Navigation” (1938).



Edwin A. Link and Captain P.V.H. Weems demonstrating the Celestial Navigation Trainer.

The first CNT was delivered to Great Britain in 1941.  The immense value of the CNT was recognised immediately, both in Britain and the US.  Compared with today’s computer-driven, full motion flight simulators, the CNT seems archaic, but in 1941 it was a marvel of design.  Hundreds of simulators were built during WW2, so many that maintenance and instruction manuals were necessary for their continued operation.




With over 210,000 square miles of terrain to choose from, instructors could select missions to be accurately flown over American, Japanese, or German areas.  Typical training missions started with a crew being given a flight plan and target.  The navigator practiced his art to direct the pilot to the target, when the crew began their bombing run.  The navigator then switched places with the bombardier, who could practice with a working bombsight.

Although navigators were trained in celestial navigation, this was mainly used by the Ferry Command, as they delivered about 10,000 aircraft from USA and Canada to europe.

The need to avoid detection, flack and searchlights, meant that on bombing flights in Europe, dead reckoning was the primary means of navigation.  But help was at hand and early in 1942 the first British hyperbolic navigation aid (Gee) became available. The virtue of Gee was that it was simple to use and it produced a very accurate fix in about one minute (compared with the much longer time it took to obtain a three-star fix). At height its range was 300 miles or so; but it was subject to jamming. Amongst other things it also provided an excellent homing device.

The American LORAN system, based on similar principles but using medium-wave frequencies rather than VHF, was later invaluable on the transatlantic route with its greater range.



In 1953, Weems was awarded the Magellanic Premium, an honour given for contributions to navigation, astronomy or natural philosophy. This has been awarded only 33 times since it was established in 1786.

For the watch collector, he has the award for the first Patent, and watch with a rotating bezel.

Weems watches : WW2 and later


The RAF expansion schemes from 1934 to 1939 provided the opportunity for forward planning for the RAF and this was accelerated after the declaration of war in 1939.

One item which needed to be procured was a hacking watch for pilots to assist with accurate navigation. This needed to be simple to use for dead reckoning navigation, not elaborate based on star shots and sidereal time using the siderograph featured above.

British and American air forces held joint meetings regarding the design of the American A-11 watch, which in Britain was sourced for the RAF and labelled the 6B/159.

The watch was to have a hacking facility, and the Weems second setting rotating bezel had provided this in a robust way, helping to simplify avigation for about 10 years.  The Weems A-11 was initially manufactured in accordance with US military specification 27834, published in August 1937.

The British military deemed the A-11 Weems model too small at 27mm diameter, but  Longines had produced a 34mm version since 1937, as shown below.

The 1939 Longines Weems model, serial number 5940884, is a 34mm diameter model, with blued spade hands, and red sweep second hand.  The bezel lock is at 4 o’clock.

The 27mm diameter type A-11 was standardised by the United States Army Air Forces in May 1940, and had leaf hands as did the commercially available second setting watches at the time. The bezel lock is at 2 o’clock.

The RAF purchased 34mm pilots watches from 1940 onward, and engraved the case back with the part number 6B/159.  Open ended leather straps were fitted prior to issue. This watch was also known as the Mk. VIIA.  Early watches had a Weems rotating bezel, but later hacking movement models dispensed with this.

The Weems 6B/159 with specification Mk. VIIA needed to meet the following requirements of Building Specification G.535 :

The movement needed to be wound by the crown instead of using a separate key. The movement should run for a minimum of 36 hours (fully wound).  The hands should be made of blued steel and the case should have a rotating lunette. The case could be made from steel, chrome or hardened brass. The dial needed to be light silver or white (like enamel). The deviation needed to meet the following requirements: after three hours +/- 3 seconds, after six hours +/- 5 seconds, after twelve hours +/- 8 seconds and after 24 hours +/- 15 seconds.

About 7000 Weems 6B/159 watches were produced to this specification, and they were individually numbered xxxx/40 on the case back.

There were five manufacturers of these timepieces; Longines, Omega, Jager-LeCoultre, Zenith and Movado.   Omega, Zenith and Movado used the same case.

The Longines Weems is thought to be the most common, and the Movado the least common.

The watches were ordered in early 1940, and delivered in the first half of 1940.

The original January 5, 1940 order note for 2000 Omega Weems CK 2129 watches, 6B/159 is shown below.

omega weems

And a compilation of the issued versions of these watches is shown below.

6B/159 Weems models.


The Longines Weems 6B/159 models are numbered in the approximate range 1800/40 to 3700/40.   A typical serial number of the watch movement is 5934652 for case 2340/40.    This makes the movements a few thousand earlier in production than the smaller A-11 Longines Weems, e.g. with a serial number 5938556 for case 40-662.

6B/159 Longines Weems cal 12.68N with original flanged crown.  The spade hands are identical to the 34mm diameter 1939 model seen above.

The back cover is marked with “Goldsmiths & Silversmiths” who procured the watches.  “AM” stands for the Ministry of Air Force (Air Ministry).

The case serial number for all five manufacturers of 6B/159 watches runs sequentially, and the model above is 2340/40.

Observed serial numbers for the Longines models range from at least 1893/40 to 3691/40.

Another 6B/159 dial shown below with original crowns.   The spring bars were fixed.

6B/159 Longines Weems

A few dials have been seen with an open 6 and 9.

Civilian models exist outside the 6B/159 order, and serial number 5992610 is shown below, with baton hands, from about 1940.   The case back was sterile.

Other 34mm cases exist, a Longines Weems with lumed baton hands below is one  of the last Weems with serial number 7523472 of 1947.

Below is a US Navy Academy embossed dial from the early 1940’s, with baton hands.


Below is a RCAF sub seconds issue with a white dial.  Serial number 6155664 calibre 10L of about 1940.

And a black dial model from about the same time, with smaller sub seconds, sold by Antiquorum in December 2004.

Finally, a 34mm version with no bezel lock, and the cal 12L fitted, serial number 6481439, about 1942, and dial with baton hands.



The Longines A-11 watch was produced just after the 6B/159, and is smaller at 27mm.   Just over 1000 were thought to be made, as case numbers run to at least 40-1075.      The dial is usually sterile, but rarely is signed Longines.    Leaf hands were used.



The movement was  cal 10L, and signed U.S. ARMY A.C.



The issued instruction manual featured the signed dial of the time.

A gold filled U.S.Navy presentation model from 1942 carried the cal 10L, movement signed U.S. ARMY A.C., so this signed movement was not confined to only A-11 watches.


Other 27mm Longines Weems continued to be produced outside the A-11 range.

A stick hand signed model below.

Serial number 6576547 from about 1942 had baton hands.

Serial number 6580945 had applied Breguet numbers.

A black dial model with baton hands is shown below.

An advertisement in January 1947 Flying magazine indicates that the leaf hand model continued in production until after the war.

The Longines 6B/159 model is seen below on the wrist of Sub Lieut (A) W N Jones, RNVR, Observer Fleet Air Arm, in Malta.

While Longines produced watches before and after the war, the other 6B/159 manufacturers only produced watches in 1940.  The Zenith and LeCoultre are shown below alongside the Longines.


The Zenith Weems has thicker numerals on the bezel.   It has one spade hand and an hourglass syringe hand.   The Omega, Zenith and Movado 6B 159 all used the same case, with a cam lever set into the case at 4 o’clock to lock the bezel.

The model number 6B 159 is engraved on the case back without the  / .

The movement was the Zenith 106, and case numbers are seen in the range 5586/40 to 6301/40.   Zenith movements are sometimes re-cased in Movado cases, (and vice versa), as the cases are identical.



The Cal 150MN movement was used in this model, with a spade hour hand and a tapered syringe second hand.

Observed case numbers range from 406/40 to 1579/40, with either stainless steel or plated bezels.

A Movado on a Bonklip strap is shown below.



Sometimes the Movado Weems is seen with 83817 on the dial in purple dye, or faded purple dye as shown on the 2 examples above.   There is no explanation for this.

The Movado dial sometimes unsigned.

The bezel lock mechanism housing for this case is shown below.

Movado later produced a black dial Weems model in 1950, with cathedral hands, 17J cal 127 movement and about 36mm diameter.


This watch has the Cal CK2129 movement, with 2000 ordered as noted above.

Omega case numbers have been observed in the range 3634/40 to 5580/40

The dial has a spade hour hand and a thin needle pointer second hand.

The dial is signed OMEGA with the Omega symbol.



LeCoultre made 34mm diameter watches for the RAF labelled 6B/159, and for the USAAF labelled A-11.   The cases were identical.

The 6B/159 case numbers observed are in the range 7155/40  to  8530/40, and about 600 USAAF A-11 watches were made.

The 6B/159 case back read  “S. S. & S” for Samuel Smith & Sons, who procured the watches for the Air Ministry.

The LeCoultre models have the most dial variations.   Blued leaf hands were used, but the dial can have radial numbers, and can be sterile.

The bezel has numbers every 5 minutes, the only 6B/159 watch to do so.

As for the Movado, 83817 in purple dye is sometimes seen on the dial.



Below, sterile dial, with radial numbers.

jlc weems


Below, signed dial with non radial numbers.


A USAAC model is shown below, case number 468.   Many case numbers were not engraved on this series, other than the LeCoultre 5 digit case number.



In about 1942 Wittnauer brought out a 27mm diameter Weems watch, signed Wittnauer, or Wittnauer Weems.

The movement was a Wittnauer 10TS, based on the Revue 56.

Production continued through and after the war, and a variety of dials exist.

Baton hands, gold filled.

The case back was sterile, but often personalised.

Stick hands gold filled.

Stick hands

Wittnauer 10TS movement

24 hour dial

24 hour dial black


Below is a NOS Wittnauer  in original box with price tag $43.76 attached.



The Weems bezel was a robust way to provide a hacking facility on a watch, but it was crude compared with newer movements which allowed hacking directly. Throughout WW2 and soon after, the need for hacking watches meant that the Weems bezel continued in production, but as demand diminished, the Weems bezel disappeared.