Here we have a circa 1942 Ebel 6B/159, later 6B/234, WW2 RAF Issue Pilot/navigators watch. It has the full stainless-steel case, measuring 32.25mm with the snap-on bezel and case back. The dial is bright and has ageing associated with wear, with the black Arabic numerals and minutes/seconds railroad track. It has the thermally blued handset with the spade and whip style hands. To the right is the well sized crown. To the rear, the case back has the full issue engraving ‘A.M 6B/159 234, 8639/42’. Inside it is signed with the reference 9101001. It has the serial number 1442, which matches with 442 on the lip of the case. The movement is a later Ebel calibre 101 which is manual wind and has shock protection. The original calibre 101 was non-shock with a different going bridge. It is in good condition, keeping accurate time.
The 6B/159 watches were issued to pilots and navigators in the RAF, who required extremely accurate timekeeping. Other crews with less sensitive timekeeping needs were issued 6B/234 watches. The 6B/159s were manufactured by Ebel, Omega, Jaeger-LeCoultre, Longines, Movado, Waltham, Cyma and Smiths.
The 6B code is the RAF stock code for navigational equipment to be used onboard an aircraft. The watches have the clear central second hand, vital for accurate timing and use in an aircraft. To further aid this, the central second hand also has hacking function, allowing for exact second hand setting.
The watches were vital in navigation and could be used to make dead reckoning calculations. Dead reckoning is the process of calculating the current position of a moving object (a plane), by using a previously determined position (fix) and incorporating estimates of speed, heading and elapsed time.
In 1942 the Ebel 6B/159 was issued with the calibre 101 movement. There was an estimated 1500 issued, with the dials very similar to the 1940 issued Ebels. Their production numbers make them one of the rarest of the 6B’s issued to British pilots and navigators during WW2.
This example was later reissued as a 6B/234 which indicates use for general service by airborne and ground crew.
The watch is modelled on a 7.5” wrist circumference.
Please see the images as these compliment and aid the description provided below. A further condition report is below.
Dial:
The dial is original and is in decent condition for the age. It is an off-white tone with marking and scratching associated with age. The signing is good and clear in the black tone. The minutes/seconds track and hour markers are good and clear.
Hands:
The hour and minute hands are correct. They are thermally blued and have the darkened tone. There is no bending or scratching and they are in good, aged condition.
Glass:
The acrylic crystal is a replacement which is in very good condition.
Crown:
The crown is formed of Stainless Steel and is a decently matched replacement. It is slightly smaller than the original. It functions well.
Case:
The case is formed of Stainless Steel and is in good condition for the age. It has light scratching associated with age. The lugs are good, with the fixed bars being strong.
Caseback:
The snap-on case back is stainless steel and has the polished finish. The issue markings are clear.
Strap:
The watch comes on a new leather strap for fixed lugs.
Movement:
The movement is a later Ebel calibre 101 which is manual wind and has shock protection. The original calibre 101 was non-shock with a different going bridge. It is in good condition, keeping accurate time.
It is keeping time to within 30 seconds variation per day, with an amplitude of 250 degrees and a beat error of 1.8m/s.y is unknown, but it is in good condition. It’s keeping time to within + 25 seconds a day, with an amplitude of 320 degrees and a beat error of 0.5m/s.
Case dimensions:
Case width: 32.25mm
Case width with crown: 35mm
Case length: 32.3mm
Case length lug to lug: 40mm
Case Depth: 12mm
Lug width: 18mm