Thanks, Bob and Christian & Nick
Christian, where did you find those drawings, if you don't mind me asking?
I thought that I had most of the available reference material on these, just goes to show there is always something else hidden away!
A little bit about the design......
HMS Staunch, the original 1867 Rendal gunboat, was designed and built at Armstrong's. Fitted with an 9" Armstrong smooth bore, muzzle loading gun. On tests the boat proved to be a sound design, and orders were placed for a further 20 craft, built by different ship yards, with modifications to be made accordingly.
The Armstrong gun on these boats was a 10"muzzle loader, which was originally designed to be loaded below deck. The gun platform was to be raised and lowered on hydraulic screw jacks, one at each corner of the gun platform.
This idea was abandoned for Mastiff and subsequent boats, because the rate of fire was extremely slow, at 6 to 8 minutes per fired round. because of the reloading procedure.
The boat was 85 feet in length, 26 feet beam and a draught of 6 feet.
two sets of single cylinder engines at 200 IHP giving a designed speed of 8.5 knots
Complement of 30 officers and men.
Mastiff was renamed in 1914 to Snapper, put on the sale list in 1919 and sold for scrapping 28.11.1939.
Everything that should move in reality, moves on the model. The gun carriage slews on the rollers, elevates using the rack, recoils on the bed way, the run back winches, have working gears, and when rigged will run the gun back to the firing position. All the locking pins are removable, and suspended on 40 links per inch chain.
I think in total there are over 350 parts to the weapon, all brass, aluminium and styrene. and about 290 man hours to machine and build it.
Ian