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).
Material characteristics and friction coefficient of the Ferodo brake lining on the 40/50 chassis rear brakes.

Identifier  ExFiles\Box 32\2\  Scan037
Date  3rd October 1922
  
X3458

40/50 CHASSIS. REAR BRAKES.

Referring to Wd{Mr Wood/Mr Whitehead}2/NJ7922 and the Ferodo Company's letter of the 5th ultimo., written as a result of my memo BY14-P31822, I regret pressure of work has prevented me dealing with this previously, but as reviewed by myself I would certainly like to make the following remarks;-

(1) The weight of the material which was covering the working face of the fabric, may, as stated, only have been .25 grammes, but the question of weight does not enter into the matter, in as much as practically the whole of the wearing surface of the liner was covered with the material in question, and therefore if the material had a lower co-efficient of friction than the Ferodo itself, it would certainly, although apparently insignificant from a weight point of view, alter the characteristic of the material.

(2) We agree that Ferodo's object in adding the dressing is merely a question of obtaining uniformity of color, but the point I would like to press is, that since the material did, in this particular case, as well as in others also work itself out on to the face of the fabric, it would be better if some coloring material could be devised which had not any body, and was in fact a coloring material, such as a dye which is a solution in a liquid and would not have any material bulk whatsoever.

After thoroughly considering Messrs. Ferodo's communication, I do not feel that it actually gets down to the question we raised, and from this point of view the reply is unsatisfactory. In the meantime we will do what we can and check out whether the removal of the material from the face of the lining does, or does not, bring back the co-efficient of friction, and providing we could prove our point we should certainly ask Messrs. Ferodo to alter their coloring ingredient altogether.

With reference to the question of supplying a back axle complete with brakes and drums, I have discussed this matter again with Hs{Lord Ernest Hives - Chair}, who informs me that he thinks it would be better for us to carry out the experiments ourselves, as we would get the information in question first hand, and any incidental point which arose during the testing would be borne in upon us in a manner which could not possibly occur if the testing were done elsewhere and not under our supervision.

I return Messrs. Ferodo's letter herewith.

BY.{R.W. Bailey - Chief Engineer}
  
  


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