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).
List of queries concerning the mounting of 40mm Mark V guns onto an Oerlikon Mounting, specifically regarding the armoured shield, sights, and shoulder rest.
| Identifier | ExFiles\Box 176\3\ img015 | |
| Date | 30th July 1940 | |
| C O P Y. To Hm.{Capt. W. Hallam - Head Repairs} c. to Ve. c. to Rm{William Robotham - Chief Engineer}/RJH. c. to Ev{Ivan Evernden - coachwork}/JD.{J. Draper - Frames} Ev.{Ivan Evernden - coachwork}4/JH.30.7.40. Re FIRST 25 40 MM. MARK V GUNS ON OERLIKON MOUNTING 3.SLA. We suggest that answers to the following queries should be obtained from the Naval Authorities during our visit to Whale Island. 1) Armoured Shield for Gun. We have received a drawing of some armoured shields for the Oerlikon gun and mounting. It would appear that the Oerlikon gun is parked in a horizontal position with the mounting fully closed behind the deck armour. When firing horizontally, the gunner's eye is 6'1" above the deck, in other words, it cannot be fired horizontally. We want to know - (1) Will our gun be parked horizontally on a fully closed mounting behind the protected deck armour in which case it will be like the Oerlikon gun in that it will not fire with 12° depression. (2) Because our rear sight is further from the trunnion than the Oerlikon, the horizontal angle of vision provided by shields on the mounting will be much less than that of the Oerlikon. Does this matter? These shields appear to protect the layer and the gunner only when firing around the horizontal. (3) The exact purpose of these shields and whether we can modify the design to make them more adequate to fulfil this purpose of our gun. These slabs of 1/2" steel will weigh approximately 200 lbs. and already the weight will overload the balancing springs in the Oerlikon Mounting causing the gun to elevate with difficulty. 2) Sights. We want particulars of the final sights. 3) Shoulder Rest, Strap and Handle. We want approval of the shoulder rest, support strap and handle. | ||