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).
History of development report on Lucas Helix type motors, detailing test results and failures.
| Identifier | ExFiles\Box 165\7\ img037 | |
| Date | 20th January 1950 | |
| -3- RM{William Robotham - Chief Engineer}/RC.{R. Childs}1/FMA. 20.1.50. History of Development. Serial No.1673. The first Lucas Helix type motor was fitted to B.40. MK.II No.1. engine. This motor failed after 50 starts on the test bed due to burnt relay contacts. The motor was returned to Lucas by JRR/RD. (2209 B - 3.12.48.). The motor was repaired and returned to us 9.12.48; it was then fitted to B.40 MK.IIA No.1. engine for a 100 hr. type test at Crewe, but failed during this test due to burnt relay contacts and a fractured relay-armature hinge. Motor returned to Lucas by JRR/RD. (Solid test bed mounting ) RM{William Robotham - Chief Engineer}/RC.{R. Childs}6/DH.{D. Henderson - Showroom} 21.4.49. - File 2209 E.{Mr Elliott - Chief Engineer}) Serial No.39. Lucas had modified the teazer field system on this motor so as to reduce the current through the teazer relay contacts from to 50 to 10 amperes: this modification appreciably reduced the burning of the relay contacts. (See sheet 2). This motor failed on the test bed after four hours running on B.40. MK.IIA No.1., during this time only 10 starts had been made. In this case engine vibrations broke the armature hinge of the relay. ( Solid test bed mounting ). Motor returned to Lucas by JRR/RD. 4.49. Serial No.62. Received from Lucas 30.3.49. The relay hinge spring on this motor had been modified to more evenly distribute the stress on the bending section. See (b) in sheet (3). This motor failed after 10 hours running on B.40. MK.II.A No.2 engine, during which time, 6 starts had been made. ( Solid bed mounting). In the above case, both the relay armature-hinge and the relay mounting bracket had fractured. The Solenoid assembly complete. Cont'd.... | ||