The gun is a 12 inch howitzer built by Armstrongs of Elswick, Newcastle, and the trolley wagon was built by Birmingham Carriage and Wagon Works. After the army had been taken off the Dunkirk beaches most of the heavy equipment and weapons had been left behind. These guns were primarily intended for mobile coastal defence and followed the practice of armoured trains.
The model is constructed entirely from plastic sheet, with the usual steel wheels and some other small bits in brass. The rivet heads have been cut off from cast components supplied by Calibre 35 and supper glued to the platework. The rough estimate of rivets is about 4,000. The gun is designed is to be lowered onto the track when preparing for action. This is done by having the bogies attached to large box sections at each end of the trolley. These are raised and lowered by large screw threads and I have managed to make the model operate in exactly the same way.
The gun was accompanied by a warflat which carried the outriggers and other large lumps of equipment, these were lifted off by a small hand crane. The outriggers and spades in the model can be slotted into the holders on the trolley for traveling.
The gun barrel is plastic tube and in the absence of a lathe I am planning to create the waisted shape by using the same technique as the original gun makers. The barrel will be impaled onto a length of rod which will be mounted into roller bearings from a radio controlled car. A small electric drill will rotate the barrel and I can shape the barrel.
The other main items to complete are wheel axle boxes, and lots of rivets.