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).
Deflection measurements and load calculations for the Goshawk II chassis frame.
| Identifier | WestWitteringFiles\L\April1924-June1924\ Scan58 | |
| Date | 1st May 1924 | |
| R.{Sir Henry Royce} R.{Sir Henry Royce} 235a (100/T) (S. H.{Arthur M. Hanbury - Head Complaints} 157 11-8-20) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 2500 TO Fs.{F. Steele} FROM DA.{Bernard Day - Chassis Design} ORIGINAL DA{Bernard Day - Chassis Design}2/M13. 5. 24. re. GOSHAWK 11. CHASSIS FRAME DEFLECTION. /4260 You sent us last Oct. F.52766, shewing the various particulars concerning the deflection of Goshawk frame as it is now, and with tiebars etc. We presume the total load of 5200 lbs is the load imposed upon the total frame, and that each side channel was called upon to carry half of this. Since the maximum weight of the whole car fully loaded with passengers is limited by the guarantee to 39 cwts, (4370 lbs) we think that 5200 lbs for the distributed load carried by the frame might be rather excessive for the test, seeing that actually the distributed load is 39 cwts, less the weight of the 2 axles, wheels, and half the propeller shaft. Possibly you allow this extra weight to account for bump. We would like to know how the deflection was measured, and presume that a spring was stretched between the 2 extremities of the frame, the latter being supported at the centre of its springs. On analysing the deflections we are given to believe that considerable experimental error may have crept in; for instance in type 1. between B & C there is a deflection of .145 - C & D .080 - D & E .135 - whilst the frame and the bending moment diagram do not point to any sudden change of deflection at that point. Since this question of frame deflection is of interest to us now both in connection with body underframe experiments - G.111. & EAC.1. - we would be glad if you could check these experiments by repeating them if you have the (1) | ||