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).
Dynamo charging requirements for tank engines.
| Identifier | ExFiles\Box 62\3\ scan0392 | |
| Date | 9th September 1933 | |
| A6142. E.{Mr Elliott - Chief Engineer} From Hs{Lord Ernest Hives - Chair}/Wst. c. to By.{R.W. Bailey - Chief Engineer} c. to Wor.{Arthur Wormald - General Works Manager} c. to F.{Mr Friese} c. to Mx.{John H Maddocks - Chief Proving Officer} Hs{Lord Ernest Hives - Chair}/Wst.1/MA.9.9.33. DYNAMOS FOR TANK ENGINES. We had a discussion with Major Howard and Capt.Hodgkinson yesterday regarding the dynamo charge requirements of the tanks fitted with R.R.engines. They stated that with the new scheme of wireless receiving and transmitting on the tanks, they would require two batteries and a continuous charge from the dynamo of approximately 20 amperes at 13 volts. They also want the automatic vibrator regulator control. The dynamo now being fitted to the tank engines is our ordinary chassis dynamo designed to operate at a relatively low engine speed i.e. low cutting in speed and in consequence has very definite limitations with regard to maximum ampere output consistent with safe heating. We told Major Howard that these limitations governed by chassis requirements was the reason the dynamo only gave a maximum output of 12 amperes. If the engines on the tanks were always running at say above 1000 R.P.M. when the dynamo charge was required there would be little difficulty in our being able to boost the dynamo output up to 20 amperes by raising the cutting in speed due to a reduction in the number of armature conductors etc. Major Howard definitely stated that they wanted 20 amperes and gave the assurance that this output would not be required with the engine running slowly, i.e. below 1000 R.P.M. | ||