From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Comparison table of gun specifications and a discussion on gun placement.
| Identifier | ExFiles\Box 175\1\ img004 | |
| Date | 20th December 1940 | |
| -2- The table referred to as being enclosed is as follows:- ROLLS ROYCE VICKERS ARMSTRONGS. BOFORS. Diameter 40 m/m 40 m/m 40 m/m 40 m/m Calibre 50 40 50 60 Gun Weight 336 lbs 590 lbs 655 lbs ? Mounting Weight 700 " 1676 " - ? Total Weight 1036 " 2266 " - 1950 lbs. Elevation 60° 85° 85° 90° Repression 12° 5° 5° 10° Rounds per min. ? 200 200 120 Loading Hand singly Automatic. Automatic. Automatic. Muzzle Velocity Feet per sec. 2440 2000 2461 2750 Mr. Thornycroft's criticisms are interesting and I think there is some merit in them, although I cannot see the point of using a fixed gun. There are considerable differences of opinion as regards the position in which the gun should be placed on board. The conventional thing is to mount the gun as far aft as possible as this gives a much steadier gun platform, but it has the disadvantage that the arc of fire is limited by the obstruction of the conning tower forward. With the position proposed by Mr. Thornycroft it would probably be possible to fire in every direction as the deck in front is very much higher than the deck astern, and it would probably be possible to fire dead aft over the top of the conning tower. If you will let me have your comments I will pass them on to Mr. Thornycroft. -------------------- LH.{Mr Haworth} | ||