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).
Design change to the frame tie rods for the 40/50-HP model to reduce stress and prevent cracking.
| Identifier | ExFiles\Box 67\1\ scan0188 | |
| Date | 19th August 1926 | |
| X9380 Hm{Capt. W. Hallam - Head Repairs}/NRC{N. R. Chandler}17/D19.8.26. Re Frame Tie Rods - 40/50-HP. I suggest that the eye to which the rear diagonal member of the frame tie rod is attached, should be made integral with the bracket for swivel pin at centre of rear spring. This would mean lengthening the rear diagonal tie rod by about 2 1/4". I do not suggest that this would materially alter the total bending moment or distribution of stress on the frame, but it would considerably reduce the local stress on the bottom flange of the channel where the present tie rod bracket is bolted on. I think the metal of bottom flange of the frame, round the 4 bolts securing the tie rod bracket, is locally highly stressed and punished by the continually varying pull of the tie rod, and it is from these bolt holes that cracks have been observed to start. The real effect of making the tie rod eye integral with and rigid with the spring pin bracket, would be to distribute the stress due to the tie rod pull, over a much larger area of the frame channel. Hm{Capt. W. Hallam - Head Repairs}/NRC.{N. R. Chandler} NRe | ||