Specifications for high-rating springs to be used in an experiment to turn the engine into a harmonic damper.
| Identifier | ExFiles\Box 14\5\ Scan309 | |
| Date | 26th October 1934 | |
| L7005 To RHC. {R. H. Coverley - Production Engineer} Hs {Lord Ernest Hives - Chair} /Gry. {Shadwell Grylls} 3/KW.26.10.34. Engine Mounting - 27-EX. We wish to try and damp the road shocks on this car by using the engine as a harmonic damper. This means replacing the engine foot rubbers F.84417 by high rating springs as follow :- Wire size .300 Outside dia. of helix 1.700 - 25 1 1/2 working coils; 3 total coils, 1/4 coil ground square each end, send open ended. Free length 1.200 - 25 Load when compressed an amount of .2 to be 440 lbs. ± 5%. Rate 2200/lbs/in. Will you please make a set of four springs; altering the type of end coiling if necessary to get the rate within ± 5%. Ha/Gry. {Shadwell Grylls} | ||
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).