The failure of a front bumper bar on a B. 56. BN. Bentley, detailing the cause and suggesting modifications.
| Identifier | ExFiles\Box 83\4\ scan0006 | |
| Date | 18th October 1935 | |
| F.J.H. 4200a HOTEL DE FRANCE. CHATEAUROUX(French test region). Indre. France. GWH {George W. Hancock - Head Chateauroux} /3/JAB. 18th October 1935. To. Hs {Lord Ernest Hives - Chair} /Rm. {William Robotham - Chief Engineer} o to: From. G.W.H. B. 56. BN. {W.O. Bentley / Mr Barrington} - BENTLEY. The front Bumper Bar fell off at the Offside during yesterday afternoon's run, and dragged under the road wheel. It is needless to say Providence was once more in our favour. The fault lies in the method of fastening the bolt. The 3/32" piece of wire, in theory called a taper pin, had been sheared when the bumper bar was fitted. The pin in question has to stand the twisting torque of an half inch nut being tightened up. What has happened is, in the first place, the stud has not been screwed up to the end of the thread in the screwed plate in the dumb iron recess. The length of the screwed portion at the front end not being sufficient, the nut in tightening up the bumper bar has come to the end of the thread and further tightening turned the stud, shearing the pin. We would suggest a larger allowance be made in the length of the thread at the front end to obviate the latter fault. At the other end a larger pin be used or better still if possible, the stud to be swayed over or drilled and opened out by a taper drift. -------------- G.H.Hancock G. {Mr Griffiths - Chief Accountant / Mr Gnapp} W. H. {Arthur M. Hanbury - Head Complaints} | ||
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).