What are the differences between Lemania's Vintage Military One-Push Chronographs 1, 2, and 3?

Hello, I'm Seno from Militan, a vintage watch specialty store.

In this article, we will introduce Lemania's one-push chronograph.

If you want to watch the video, click here ↓

The history of Lemania can be found here:

The one-push chronograph for the air force is very popular among Lemania watches, and is available in first, second, and third versions.

Each one is a very cool and beautiful watch, so I'd like to introduce them to you.

Lemania One-Push Chronograph 15CHT First Model

Lemania One-Push Chronograph First Model Tritium Version

Lemania One-Push Chronograph First Model Radium Version

The first model was characterized by a white dial and the use of radium and tritium in the luminous paint.

Radium was originally used as a luminous material in military watches.
However, it was discovered along the way that radium had too much radiation, so it was replaced by tritium.

In submarines, where radiation is particularly easy to detect, watches containing tritium, a low-radioactive substance, were given priority in distribution.

This time, Lemania 1 to 3 are all for the Air Force.

The first image is the tritium version.

There is a T in a circle under the LEMANIA mark.
This is the mark that indicates that it is tritium.

And at the 6 o'clock position is the well-known Broad Arrow mark which indicates British military use.

Lemania One-Push Chronograph 15CHT Second Model

Lemania One-Push Chronograph 15CHT Second Model

From the second model onwards, the dial becomes black and the numbers become white.
I think these are like this according to WWW standards.

The only luminescent paint used is tritium; radium is no longer used.

There are two types of numbers written on the back of the case.

Royal Navy (0552)

Air Force (6BB)

This was to make the watches distributed to the Navy and Air Force easier to understand.

Lemania One-Push Chronograph 15CHT Third Model

Lemania One-Push Chronograph 15CHT Third Model

By changing from a second to a third watch, the crown guard is now attached to the case body.
The addition of a crown guard changes the asymmetrical look to create a very cool design.

By the way, I like this third one the best.

What's in the movement?

All the watches, from first to third, are equipped with the same movement.