British 4.2-inch Heavy Mortar

[horsa]

Shot below for reference shows three mounts with the first being for the 3-inch mortar, middle one is for the lightened 4.2-inch mortar and the third one being for the towed 4.2-inch mortar.

The lightened version would appear to be based on the standard 3-inch format with the addition of a third leg, third leg locking bar which might not be visible in the shot and of course the cradle for the larger 4.2-inch barrel. Worm gear seems to be the same on each of them. There are differences in the locks for the standard legs on both mounts but I think that is a difference found in early and late 3-inch mounts and not something to differentiate the 3-inch vs 4.2-inch patterns.



Nomenclature is not official as I don't have a manual handy so hope you can decipher what I'm calling things in this post.