Thanks for your answer, ROLAND1369,ROLAND1369 wrote
The picture is a 4 inch CP mark IX. Her is a similar weapon being mounted on a ship.
Note both the recoil system and the unusual positioning of the traversing wheel on the right side of the pedestal.
What is your opinion about the images posted on 17 Feb 2018 and 14 Mar 2018 ??
Regards Sturm78