US 6" Driggs trench mortar

[greif]

I found this blueprint of a 6" Driggs trench mortar with case.
Was this actually in service or was it experimental or for export?
And what kind of case is shown? Was it made partially of cardboard?

 

[Hoeksel]

I remember finding drawings as well in the Dutch archives, but since we went there together, are we talking about the same thing? If not, i will look for you.

 

[greif]

Same source, but I have only this drawing and no further written information.