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).
Table of torsional strength test results in lbs.ft/degree for a frame with various modifications.
| Identifier | ExFiles\Box 109\1\ scan0074 | |
| Date | 14th November 1938 | |
| -2- Rm{William Robotham - Chief Engineer}/Clm.{D. D. Clapham}3/MH.{M. Huckerby}14.11.38. TABLE OF TORSIONAL STRENGTH IN LBS.FT/DEGREE. Initial Weight 318 lbs. Condition of Frame. Front to Rear Dash to Rear Dash to Front Increase in Weight. As received 1020 1585 2875 None Rear of cross boxed in 1150 1900 2910 12 lbs. Rear of cross boxed in, and gussets welded on top. 1230 1975 3270 None Rear of cross boxed in, and gussets welded top and bottom 1275 2025 3440 None. Rear of cross boxed in, gussets welded top and bottom, and thick plates in centre of cruciform 1350 2110 3745 10 lbs. Rear of cross boxed in, gussets welded top and bottom, thick plates in centre of cruciform, and centre portion of side members boxed in. 1435 2200 3800 11 lbs. | ||