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).
Operating conditions and specifications for two types of fan belts, EB.1775 and E.89343.
| Identifier | ExFiles\Box 135\1\ scan0162 | |
| Date | 19th July 1938 | |
| Rm{William Robotham - Chief Engineer}/Std.12/MH.{M. Huckerby}19.7.38. OPERATING CONDITIONS OF FAN BELTS. (1) EB.1775 Belt. Ext. dia. of driving pulley (C/shaft) - 5.850" Ext. dia. of driven pulley (fan) - 6.500" Speed ratio - 0.9/1 (Fan speed/engine speed). Max. r.p.m. of driving pulley - 4500 r.p.m. Max. h.p. transmitted by belt - 12 H.P. (2) E.89343 Belt. Ext. dia. of driving pulley (c/shaft) - 5.500" Ext. dia. of driven pulley (fan) - 5.500" Speed ratio - 1/1 Max. r.p.m. of driving pulley - 4500 r.p.m. Max. h.p. transmitted by belt - 20 H.P. approx. | ||