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).
Chassis frame failure for chassis 3-LC, with an analysis of the cause and recommendations for strengthening a bracket.
| Identifier | ExFiles\Box 47\2\ Scan136 | |
| Date | 25th July 1929 | |
| FY. Hs.{Lord Ernest Hives - Chair} X4117 Hm{Capt. W. Hallam - Head Repairs}/NRC{N. R. Chandler}32/MW25.7.29. re CHASSIS 3-LC - MRS. HOYER. The above chassis left W. December 1925. No record of date of delivery to Owner. Total mileage 22000 on the Continent. The frame is broken through the bottom flange of the O.S. side member, at the bracket to which the rear tension rod of the frame tie is attached. Both of the frame tie brackets F.7012/3 are broken. There is absolutely no evidence of the rear buffers having struck the axle, and there is little doubt that first of all the tie rod bracket broke as shown in Fig.1, and as a result of the pull of the tie rod, when the frame deflected, the bottom flange of the frame was then broken as shown (exagerated) in Fig.2. There is no evidence of the tie rods being excessively tight, because after removing the bolts and then offering up the bracket (with engine and gearbox in position) the bolt holes were practically coincident. There have been several other frame failures of a similar nature, and in other cases the rear tie rod bracket F.7012/3 has been found to be broken or cracked, but has been replaced before the frame was broken. This suggests that the bracket F.7012/3 should be strengthened at the point where the fracture occurs, and we think this is important because, when the bracket fails, it is only a matter of time before the frame is broken. We note that this same bracket is still used on production, and suggest that the strengthening of this bracket should be considered for production and that the strengthened bracket should in all cases be used for replacements. Hm{Capt. W. Hallam - Head Repairs}/NRC.{N. R. Chandler} WRH | ||