What really is this deck cannon ?????

[Gspragge]

From the Marine auction, described as a 90mm ? Rather looks like an 18pr., but not quite ?
Does anyone know for sure ~
18Pr's were modified for deck guns, how much they were altered is unknown to me.
There is likely some kind of manual, perhaps in the RN museum - if anyone can help
with that ? Not the most helpful museum though.

 

[wingsofwrath]

That is a "canon de 90 mm modèle 1877 de Bange" navalized by the Elswick Ordnance Company beginning in 1916 for use on Defensively equipped merchant ships (DEMS). The mount itself is derived from the Hotchkiss elastic frame (affût-crinoline) used for 3 and 6-pdrs in the 1890s, and it also has a hydro-pneumatic recoil mechanism and the mont itself had -10° and +35° elevation with 360° traverse.

 

[15 inch]

The marinized 18 Pr was a Mk.I or II barrel in a Mk.I carriage cradle, mounted on a pedestal. The only survivors I know of were installed ashore to defend the larger coastal batteries in Auckland Harbour.