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).
Examination report on electrical units following endurance tests conducted in France.
| Identifier | ExFiles\Box 97\5\ scan0186 | |
| Date | 31th May 1939 | |
| 400b To By.{R.W. Bailey - Chief Engineer} c. to HPS.{Horace Percy Smith - Experimental Factory Mgr} c. to HPS{Horace Percy Smith - Experimental Factory Mgr}/RH.{R. Hollingworth} c. to By/RB.{R. Bowen} Rm{William Robotham - Chief Engineer}/RC.{R. Childs}2/JH.31.5.39. Examination of electrical units off 8.B.V. after Endurance tests in France. First Dynamo. (Armature LOP.DB.{Donald Bastow - Suspensions}1762, Bearing Brk. LOP. DB.{Donald Bastow - Suspensions}1784, Frame and Field LOP.DB.{Donald Bastow - Suspensions}1792, commutator LOP.DB.{Donald Bastow - Suspensions}1799). The dynamo originally fitted, failed at the end of 20,968 miles owing to solder being thrown from the commutator end connections. For details see separate report Rm{William Robotham - Chief Engineer}/RC.{R. Childs}18/JH. 30.3.39. Second Dynamo. (Specification as above). This machine was fitted in place of the one that failed: it completed the remaining 10,834 miles. When examined the insulation was found to be sound, and the condition generally good, with the exception of the brushes. Of these, the positive brush was very much more worn with corresponding worn patches on the commutator. In view of the high output of the regulator and the condition of running, this rate of wear is not regarded as excessive. Experiments with brushes are in hand. First Regulator. D.34362 (Mock up for DB.{Donald Bastow - Suspensions}1922) The performance of this unit was checked on return and found to be high, i.e. 20.1 amperes at 13.5 volts cold, and about 22.5 amperes hot. This was considered to be a contributory cause of the dynamo failure. The specification for this type of regulator now provides for a lower setting. A small pip was found to have formed on the fixed (cathode) contact, otherwise the condition was good. Second Regulator. (Specification as above). This unit was fitted and run in conjunction with the second (replacement) dynamo. On return the performance was checked, when it was found that the output was on the high side, although not so high as that of the first. At 13.5 volts the output was 19 amperes cold, and about 21 amperes hot. The condition of the unit was good. Switchbox. (DB.{Donald Bastow - Suspensions}197 std.) 30,300 miles. Condition good. | ||