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).
Experiment to test the suitability of dry batteries for the Goshawk ignition system.
| Identifier | ExFiles\Box 54\5\ Scan228 | |
| Date | 1st January 1923 | |
| To R & E. {Mr Elliott - Chief Engineer} from EFC. {E. Fowler Clarke - Electrical Engineer} c. CJ. & PN. {Mr Northey} c. By. {R.W. Bailey - Chief Engineer} & EP. {G. Eric Platford - Chief Quality Engineer} c. Rg. {Mr Rowledge} & Da. {Bernard Day - Chassis Design} X3485 EFC {E. Fowler Clarke - Electrical Engineer} 2/T1.1.23. X.3485 - GOSHAWK IGNITION. We have now made the second experiment asked for in your R2/M30.11.22 of finding out if the Goshawk ignition will work sufficiently well on dry batteries for the short period of time necessary for starting the engine. We experimented with a set of 10 dry cells of the inert type, of dimensions 2.325" x 2.325" x 4.8" overall, each cell, these being field cells taken from German Army stores. As a preliminary experiment, after bringing the cell into full activity, we discharged a single cell on a small lamp. The initial volts and amperes were 1.138 and .190 respectively, which fell steadily to .736 volts, .174 ampere after two hours, and to .324 volts .141 ampere after a further three hours. On the following day the cell was again put on to light the lamp, and kept the lamp going steadily at a current in the neighbourhood of .115 ampere for 8 1/2 hours, thus indicating that as regards ampere hour capacity the cell should be sufficient for ignition purposes. A further test was done on another cell of the open circuit and short circuit current every 15 minutes after rendering the cell active. The time taken to become moderately active was 15 minutes. The open circuit voltage was 1.425, short circuit current 1.65. After three hours the open circuit voltage was 1.41, short circuit current 2.45. | ||