Rolls-Royce Archives
         « Prev  Box Series  Next »        

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).
Failure of a pendulum steering lever, debating its cause and appropriate material selection.

Identifier  ExFiles\Box 38\1\  Scan048
Date  27th August 1919
  
X.3465.

To BN.{W.O. Bentley / Mr Barrington} from R.{Sir Henry Royce}
Copy to Cu.
" " EH.
" " HM.{Capt. W. Hallam - Head Repairs}
" " EY.
" " E C.
" " Mr. Hall. X.205.
X.3465. RE PENDULUM STEERING LEVER.

On the test at the Works Mr. Hives will tell us whether this part of the chassis is weak in design or whether it is a forging crack due to wrong material or bad workmanship, anyway, it seems that no harm could occur if a slight addition is made to the section where the lever was found broken.
It should reduce the risk of fracture there, whether forging or over-stress due to fatigue.

I am not in entire agreement with Mr. Hall that a harder material would be a better policy. In fact, I think our tests should be made on the soft material, which is quite reliable in forging. At the same time, we have to thank Mr. Hall for having improved the quality of our drop forging material, in as much as the correct nickel steel to his specification is less liable to crack in the forging.

I shall expect to hear from you as follows:-

(1) It is settled that the steering lever failure is due to defective material or is the design weak at the point where the fracture occurred?

(2) Will the addition of a small amount of metal at the point of fracture lessen the risk from a forging crack, as well as increase the resistance to fatigue?

I quite agree that crystallisation due to stress is an old fashioned and exploded idea, the crystals found have always been there, due to the material being in the wrong physical condition or chemical composition. This will also be confirmed by Mr. Hall.
  
  


Copyright Sustain 2025, All Rights Reserved.    whatever is rightly done, however humble, is noble
An unhandled error has occurred. Reload 🗙