Shortly after the German Luftwaffe was regrouped in 1935 the Ministry of Aviation (Reichsluftfahrtministerium) or RLM introduced three different kinds of watches to their fighter pilots, bomber crews, and ground personnel The first one was a single/double pusher type chronograph manufactured by Hanhart and Tutima, Glashütte. The ground crew was equipped with a fairly inexpensive type of field watch. And finally there was the probably most famous type of watch: the Luftwaffe observer’s watch or Beobachtungsuhr (“B-Uhr”).
Here is the 1942 original spec sheet for a “Type B dial” B-Uhr manufactured by Wempe Chronometerwerke, Hamburg. Note the inner 12 hour chapter ring on the dial, the large crown and thick crown tube:
PRECISTA B-UHR LIMITED EDITION PRS-42
- 316L stainless steel, bead blasted finish
- Diameter 44mm, 51mm across including crown
- Lug to lug height 55.8mm
- Thickness 14.7mm to the top of the bombé crystal
- Lug spacing 24mm
- Anti-magnetic 4800 A/m
- Water resistance 50m/166ft
- Weight 89 grammes, head only
- Screw back (both view back and solid back)
- Black, type B
- SuperLuminova C3. Hour chapter: all numbers luminous. Minute chapter: even numbers luminous. Minute hash markers: all luminous
- Blued steel sword type, luminous filled. Seconds hand blued steel with white tip
- Luminous: SuperLuminova C3
- Bombé sapphire crystal with anti-reflective coating on the underside
- Unitas 6497-1 18 jewels Stop Seconde Centrale "Premium". Rhodium Cotes de Geneve (9 stripes), Incabloc shock protection, blue screws, Glucydur screwed balance wheel with Nivarox hairspring and swan-neck regulator
- Custom aviator style with stainless steel rivets (screws) and hardware with stainless steel roller buckle. Made from Premium Pittards leather
The B-Uhr was issued to all bomber crews and was mainly carried by the navigator who used it for all sorts of navigational purposes. The watch was not part of the personal equipment but was handed out before a mission and had to be returned after. The original spec sheet demanded the B-Uhr to be fitted with a very accurate centre seconds pocket watch movement with hacking second which was tested and regulated to the highest standards by the German Naval Observatory in Hamburg. Since those precision movements were originally designed for pocket chronometers the watches were very large even by today’s standards.
The cabins of German bombers were in most cases unpressurized and unheated. That is why most B- Uhren were fitted with a very long and safety-riveted leather strap with roller buckle so that it could be worn over the sleeve of the thick shearling flight jacket. Some of later versions were delivered on a shorter strap (“Kurzband”) so that they could be worn as a normal watch during missions.
A German airman checks the mission protocol before sortie. His type “B” B-Uhr is worn outside his heavy sheepskin flight jacket. Look at the inner chapter ring on the dial and the short hour hand. Only type “B” versions had this specific detail.
The B-Uhr was manufactured by 5 different companies in two dial configurations. Design and assemblage were carried out according to a strict and precise RLM spec sheet. Nevertheless there are some notable differences between the different contracts which make original B-Uhren in good condition even more desirable for any serious watch collector.
Common features for all of them were the high quality chronometer grade movements with Breguet balance springs, indirect centre seconds with hacking feature, oversized cases and crowns for superb legibility and easy winding and setting.
Here is a group shot which shows both dial versions and also illustrates the subtle differences between each manufacturer’s cases. Note the different crown and lug shapes and differences in lug spacing:
A beautifully aged Laco type “B”. The luminous material on the dial has faded to a nice cream color. Please note the three-piece case construction and that only the even numbers on the outer chapter ring are lumed. This is a detail that is not captured in most of the modern reproductions.
Key features of the original contracts:
A.Lange & Söhne, Glashütte: The Lange features a field grey coated zinc or nickel alloy case with 55mm diameter, onion style crown with thick crown tube, A and B type dials, cal. 45 and 48/1 in-house movements with three-quarter plate, swan-neck regulator and 16 jewels, gilded finish. Not all of them were assembled in Glashütte but assemblage and regulation was sometimes done by subcontractors, Wempe, Hamburg and Huber, Munich being among them.
Erich Lacher & Co (Laco), Pforzheim: The Laco features a field grey coated zinc diecast case with soldered brass lugs with 55mm diameter, onion style crown with long and sturdy crown tube, type A and B dial, very large in-house caliber Durowe 5 with22 jewels and gilded finish.
International Watch Company (IWC), Schaffhausen: The IWC features a bead blasted full stainless steel case with 55mm diameter, crowns are either cylindrical or diamond shaped for later versions, the lug spacing was also widened by 2mm for later versions to accept a sturdier strap, type A is the only dial option, cal. 52 SC (seconde central) in-house movement with three-quarter plate, 16 jewels and swan-neck regulator, gilded finish.
Walter Storz (Stowa), Pforzheim: The Stowa features a field grey coated zinc diecast case with 55mm diameter, oblong onion style crown, type A and B dial versions, Unitas cal. 2812 with 20 jewels, swan-neck regulator, nickel plated finish with Geneva stripes.
Wempe Chronometerwerke, Hamburg: The Wempe features a field grey coated 55mm zinc alloy diecast case, although some claim that at least a couple of them were assembled with 800-alloy silver cases, onion style crown, type A and B dial versions, Thommen cal. 31 with 15 jewels and cam regulator, gilded finish.
The PRS-42: our take on the B-Uhr
When we decided to make a B-Uhr our first thought was “But we have to do it properly!”. In this case “proper” starts with the correct movement and case. Putting a modern automatic movement into some vintage inspired watch just seemed not good enough.
Luckily we were able to source a small number of very rare Unitas pocket watch movements that have been adapted to indirect centre seconds modification by an expert Swiss company. This is a very expensive and even rarer movement that is exactly in keeping with the original 1942 specification for the Wehrmacht B-Uhr: It is a large and beautifully finished pocket watch movement with blued screws and Geneva stripes that completely fills the case. It also features a classic swan neck regulator and screwed balance for superb accuracy. What truly sets it apart from any competitor is its unique and improved hacking device. When you pull the crown the watch does not simply stop: the seconds hand will continue to run until it stops on the 12 hour indicator. This truly is an ingenious feature that is available on this specific movement only.
The watch case design is not taken from any specific manufacturer but is instead an amalgamation of the best design features compressed into a smaller and much more wearable watch. The case features the straight and square lugs of the Laco but they have been beefed up and slightly lengthened for good comfort.
The crown is a very large onion style crown with a thick and strong crown tube that makes winding and setting really smooth and easy. The crystal is of course a modern sapphire crystal with internal A/R coating but we managed to replicate the complex, yet beautiful domed shape of the original acrylic “Plexiglas” crystal with its several internal and external radiuses.
Like the original B-Uhr this is a three-piece case design but it’s not a snap-on bezel and caseback: the bezel and back are screwed down. It is a full CNC construction made from 316L stainless steel with a period correct dark grey bead blasted finish. The top loader design eliminates the use of a movement retaining ring. This is a high quality solution and just the way the old B-Uhren were made.
Dial, Hands and Strap
When we decided to make a type “B” B-Uhr we knew from the start that the dial was a critical part. Too many watches on the market have wrong dial layouts and what is even more important: the Superluminova is not correctly applied. Vintage type “B” dials only have the even numbers on the outer chapter ring lumed. We have done it correctly.
Also the blued hands are just as they should be. They have the correct length and width, are properly pointed, and are evenly filled with strong glowing Superluminova C3 (cream-light green) to match the lume on the dial.
The leather strap is made from camel coloured Pittards’ nubuck leather which is thick but supple and will develop a beautiful patina with wear. The strap takes most design features from the original “Kurzband” short-style strap which was introduced with later versions of the B-Uhr. It features the correct hardware and roller buckle which are now made from much more durable stainless steel with a matching bead blasted finish.
Supplied in a 1060 Peli case and with 2 years guarantee. 50 pieces only available.
Click image below to see setting procedure
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