The History and Appeal of the B-Watch Used by the German Air Force in WWII

Some watch designs not only stand the test of war, but go beyond their original function to become masterpieces.

Among them, B Watch Type A and Type B are likely to be items that collectors are eager to get their hands on.

B-watches are wristwatches issued to the German Air Force during World War II.

Its most notable feature is its extra-large case diameter of 55mm, even in modern terms.

Today, I would like to explain more about this fascinating B watch.

Laco Vintage B Watch

The video is divided into five parts

1. History of the B-Watch

2. Differences between B Watch Type A and Type B

3. All domestic B-watches

4. B-watches with Swiss-made movements

5. Understanding the engravings on the case back

Finally, here is a summary.

So let's get started right away.

History of the Luftwaffe B-Watch

The B watch (Baobachtungs-Uhr) means observation watch and is thought to have its roots in the marine watches developed by British watchmakers in the 18th century, which played an important role in sea navigation.

This watch can be said to be a masterpiece created by leading watch makers from Germany and Switzerland.

Grammatically speaking, B-Uhr is singular and B-Uhren is plural.

The B-watches were owned by the German military and were issued to the Luftwaffe's "reconnaissance pilot units" before flying, and had to be returned after the mission was completed.

Because accurate timekeeping was essential during military operations, these watches were all regulated and tested to the highest chronometer standards by the German Naval Observatory ( Deutsche Seewarte) .

In this way, watch manufacturers produced their watches based on strict specification sheets prescribed by the military.

Therefore, even though the completed B watches are manufactured by different companies, the exteriors and designs are all perfectly standardized to the same specifications.

Its specifications are as follows:

B Watch Spec Sheet

-Matte black dial with Arabic numerals and bar indexes

- The case is made of aluminum with a diameter of 55 mm.

The case color is gray

- Use luminous paint on the numbers/hands

・It must be a center second

In addition, the belt is very long and made from a single piece of leather so that it can be worn over a thick pilot's suit.

Other features unique to the B watch include a large onion-shaped crown that can be turned even while wearing gloves, and a change to a center second hand that is much easier to read compared to the Navy's small second hand.

The fact that air force watches of other countries also commonly feature a center second hand shows how important it was to have a clear second hand.

As such, the B watch came to be seen as an essential piece of equipment for perfect navigation, and its production was entrusted to companies with the technical capabilities.

At the time, five companies, four from Germany and one from Switzerland, supplied the German military with B watches .

In Germany

・A. Lange & Söhne


・Laco (Lacher & Company/Duroe)

・Walter Stoltz (Stowa)

Four companies were involved in manufacturing, and the model number was " FL23883 ."

The side of each case is stamped with the model number, FL23883 .

The engraving on the side of the B watch reads "FL23883"

FL stands for Flieger and 23 indicates that it is a navigation watch.

Now let's compare Type A and Type B.

Differences between Type A and Type B of B-watch

B Watch Comparison of Type A and Type B

There are two types of B watch dials: Type A and Type B , which has a minute display.

Type A has Arabic numerals from 1 to 11, with a triangular pointer at the 12 o'clock position and dots on both ends.

Type B has hours displayed on the inside and minutes displayed on the outside.

It is probable that even though the Type A had different lengths of hour and minute hands, it was not possible to distinguish them one after the other during flight.

Therefore, I think that when it changes to Type B, the hour hand will be significantly shorter and the design will see the time displayed on the inner circle.

The black dials and contrasting white Arabic numerals ensure great visibility.

Now, let's take a look at each brand.

All domestic B watches

At the beginning of production, Lange and Laco were the main producers, but in 1938 Wempe acquired a chronometer factory in Hamburg, which significantly increased production capacity and enabled it to supplement the limited production of Lange and Laco.

Three years later, in 1941, the specification sheet for the Type B was completed and Lange and Laco began manufacturing the Type B.

That's why Lange and Laco have TYPE A and TYPE B.

Lange uses cal. 48 and cal. 48.1, Laco uses (Duroy) cal. 5 , and these are the only two companies that use German in-house movements.

Lange Söhne B Watch

Laco B Watch

B watch with Swiss-made movement only

Both Wempe and Stowa use Swiss movements, with Wempe using the Thommen cal. 31 and Stowa using the Unitas cal. 2812 .

B Watch Wempe
B Watch Stowa

In addition, the Swiss watch company IWC , which supplied watches to both the Axis and Allied forces, produced a small number of B watches ( cal. 52T SC ) for the German Air Force.

Because there were so few of them, the number of remaining watches today is far fewer than German watches.

IWC-B Watch Type A

IWC acquired the know-how of manufacturing pilot's watches here, and would later pass on that technology to the Mark 11.

For more information on Mark 11, please see the detailed explanation here.

These five companies were the only ones that produced B watches .

Now let's take a look at the engraving on the back cover.

Understanding the engravings on the case back

B watch case back inside

There's a lot of writing on the inside of the snap-off case back, but there are patterns to it, so as long as you understand them, you'll be fine.

・Design type ( Bauart ) manufacturing company

・Serial number ( Gerät-Nr )

・Movement ( Werk-Bez )

It doesn't seem to be the movement caliber number.

I tried to look into the details, but I couldn't find anything.

・Order number ( Anforderz )

・Manufacturer ( Hersteller )

It was stamped with an identifying mark.

These watchmakers produced innovative designs that would go on to become hugely popular.

IWC 's Big Pilot is a model that inherits the DNA of the B watch while rearranging and evolving its design.

Created for the aerospace industry, this watch is antimagnetic, making it the only one of its kind in the world.

Laco offers a wide range of movements at affordable prices, but their watches equipped with ETA manual movements are particularly noteworthy.

The design of the dial and the FL23883 engraved on the side of the case are all carefully recreated to the smallest detail of the original watch, making this a model that can be called a reproduction.

These Laco watches come in 42mm and 45mm sizes. They come with sapphire crystal, riveted leather straps, excellent brightness, and Type A and B models.

The Lange and Wempe B watches available today are vintage wartime watches, but they are all very expensive and highly sought after by collectors, and for good reason.

B Watch Modern Laco


To sum up, I think that at the time, this type of design was adopted as a result of pursuing functionality, but looking back now, I think that its appeal lies in its size and ruggedness, rather than its functionality.

It's generally very difficult to get your hands on anything from that time, but there's no doubt that this is a piece you'll want to add to your collection.

So that's what I've been explaining about B Watches today.