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).
The acceptance and endurance trials of 40mm Type BH aircraft guns.
| Identifier | ExFiles\Box 176\1\ img219 | |
| Date | 8th May 1942 | |
| SECRET. To-Ho. from Ve/NP. cc-Sq-Ldr. Rm.{William Robotham - Chief Engineer} TPO. cc-[REDACTED] cc-Ve/VH. HPO/WHW Ve/NP.1/CB.8.5.42. Acceptance and Endurance Trials of Rolls-Royce 40 mm. Type BH Aircraft Guns. Acceptance Tests. On the 10th April, four prototype production, type BH guns, 12051 to 12054, converted from Naval type BD{Mr Berend} guns and assembled by Rolls-Royce, successfully passed the M.A.P. Acceptance Tests for this weapon. These consisted of the following firings :- Horizontal - 5 single shot; 5 automatic - Armour piercing. 80° Elevation - 2 single shot; 5 automatic - Break-up shot. 80° Depression - 5 single shot; 5 automatic - Armour piercing. On completion of the Acceptance Trial, the guns were stripped and found to be in excellent condition; no parts required replacing. All four guns were then re-assembled and a pair, 12051 and 12054 were despatched on the 12th to Boscombe Down for air endurance trials. The trials commenced at Boscombe on the 15th, the guns being installed in Hurricane Z.2326, fitted with new production type wings. Endurance Trial. This trial, originally called for the firing of 500 rounds out of each gun, this being the expected "life" of the gun in service, but by general agreement between D.{John DeLooze - Company Secretary} Arm. D.{John DeLooze - Company Secretary}, R.M. and B.U.S.M., this figure was increased to 1,000 rounds from each gun, the guns to accomplish the trials with a minimum of attention and under conditions approximating to those which would be found in service. Both guns successfully passed the test, the performance of the port gun, 12051, being particularly noteworthy in so far as it had only one genuine stoppage in 1,006 rounds. Rather more trouble was experienced with the starboard gun, 12054, but with exception of the extractor, all faults were diagnosed and rectified during the trial. cont'd.{John DeLooze - Company Secretary} | ||