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).
Request to test a fan belt drive for the 'Goshawk II' and enclosing a crankshaft sketch for a new 14 HP model.
| Identifier | Morton\M1.9\ img017 | |
| Date | 1st August 1921 | |
| To HS.{Lord Ernest Hives - Chair} from R.{Sir Henry Royce} Copy to CJ. ORIGINAL R5/G30/8/21 RE THIRD LINE MODEL. X4405 Thank you for telegram re "Goshawk II". Will you kindly test a fan belt drive consisting of two 4" pulleys 10" between the centres of the shafts. The fan would be approximately 13 1/2" diameter, and the speed would run up to a maximum of 5,000 revolutions, but it does not matter if the fan were not driven faster than 3,000 revs., the belt slipping during this very high engine speed of 4,000. This particular drive is to run from a dynamo shaft which is going 1 1/4 engine speed somewhat diagonally to the fan pulley. The fan itself would be carried on an arm so that the belt could be kept tight by a spring such as we are adopting for the dynamo on the 40/50 H.P. With this letter Mr. Elliott is enclosing a rough sketch of the crankshaft we are proposing for the new 14 H.P. R.{Sir Henry Royce} RECEIVED | ||