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).
From the Laboratory suggesting new lead alloys for Wilmot-Breeden bumper bar weights.
| Identifier | ExFiles\Box 118\2\ scan0284 | |
| Date | 21th August 1936 | |
| X1023 To Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} HL1/AG.21.8.36. Laboratory. Re: Wilmot-Breeden Bumper Bar Weights. (Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}4/KW20.8.36) We suggest that the lead should be replaced by an alloy consisting of 92% lead and 8% Antimony. If made from the metals this will cost approximately the same as lead. For ease of manufacture a second alloy might be considered. This should be 91% lead, 1% tin, 8% antimony. Either of these alloys will be harder than lead, sufficiently so to withstand deformation. Thus lead of about 6 Brinell will be raised to about 12 Brinell by 8% Antimony. At the same time the alloys will not be brittle. The Foundry could make these alloys. HL. HE | ||