2" mortar question

[GeoffR]

Being resonably new to this forum and a complete novice in many aspects of the topic, I would be grateful for any help with the following two questions please:

The photos show the tail of what I believe to be a British 2" mortar (the '2' on the fin?), found on the foreshore south of Harwich.
1) What does the single red fin indicate?
2) The detonator cap shows it to have been fired, but the detonator cap is still contained within the mortar fins. How does that set-up work to eject both from the mortar tube?

 

[hangarman]

The red paint means that a live cartridge has been fitted. The cartridge is retained inside the tail as there is a cap that screws on to the end of the tail and when the cartridge is fired the blast is emitted from the holes in the side of the tail.
Cheers
Gary

 

[GeoffR]

Thanks Gary, that neatly explains all. (I had omitted to include the cap in the main [third] photo.)
In my naivity I had assumed it was a smoke mortar (from a probable training area) and the holes in the tail were for the smoke exit. Thanks for the clarification.

 

[MissingSomething]

Here is a 2" tail with a fired cartridge.

 

[GeoffR]

Thanks MissingSomething. That picture shows the situation beautifully.