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).
Conclusions on the battery and ignition system for the Wraith model.
| Identifier | ExFiles\Box 164\3\ img139 | |
| Date | 18th February 1938 | |
| Rm.{William Robotham - Chief Engineer} C. Da.{Bernard Day - Chassis Design} O.{Mr Oldham} Mx.{John H Maddocks - Chief Proving Officer} O.{Mr Oldham} BY/RD. BY.19/G.18.2.38. 6021- WRAITH - BATTERY & IGNITION. Referring to Rm.{William Robotham - Chief Engineer}16/R.4.2.38. and dealing with each item separately my conclusions are as follows :- (a). Battery. (1). The evidence provided by the cold chamber shows the battery to have too small a capacity, but the fact that Wraith has been running for over a year without complaint indicates that our method of testing batteries demands reconsideration. (2). I agree with Rm{William Robotham - Chief Engineer}/Wymm's conclusions, but we must not overlook the fact that no complaint was made until last month, and except for the cold chamber it would apparently have got through into service. There should be a carefully considered schedule of tests for any new battery which would quickly and conclusively prove whether the battery was satisfactory or not apart from the fact of the Company having a cold chamber, except as an auxiliary test. (3). History. For the original Wraith body project, in order to meet what was called for in the way of height of floor from ground, overall height and position of rear seat, it was necessary to ask P. & R.{Sir Henry Royce} to arrange standard battery plates in a different manner, they did this and the result was what we have just escaped from by a happy accident of changed requirements. The battery makers were asked to maintain the capacity as for 25/30, but instead we have discovered we have only 45 amp. hours instead of 54. We should have learnt this before the project was agreed to by intensive battery tests to a carefully considered schedule. (b). Coil. Here I do not agree with the conclusions arrived at for the following reasons :- (1). From the facts recorded, it is not clear which is the better coil, as the Delco failed to start the | ||