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).
The supply and specifications of springs from supplier Firths, detailing materials and plate thicknesses.
| Identifier | ExFiles\Box 52\2\ Scan028 | |
| Date | 21th January 1922 | |
| - 2 - in poundage and camber will not affect them, whereas an alteration in width of plates or dimensions of solid and rolled eyes would do so) and we give them not later than Monday, 23rd inst. particulars of the poundages and cambers of the springs we require for production (also thicknesses of plates if any alterations are made), they will forthwith roll material (Chrome Vanadium Steel) for 50 sets of springs and will proceed with all the operations except cambering, hardening and tempering, so as to be in a position to proceed with these operationsand assembly immediately after the results of the bumping tests are known. (e) If we do this, Firths are prepared to undertake to commence delivery of the 50 sets of springs in the first week of March. (f) It will be observed that Firths propose to roll only Chrome Vanadium Steel for the 50 sets of springs! In this connection they have given me an undertaking that should we ultimately decide in favour of the less costly Silico Manganese steel they will reduce the charge for these 50 sets to the prices they would have charged if made from Silico Manganese steel. (g) Firths would like to have our opinion of the general finish of the top (main) plates already supplied. Will By. {R.W. Bailey - Chief Engineer} please let me have this. (h) An examination of the drawings already supplied to Firths shows that the following thicknesses of plates are specified:- Front Springs .250" .165 .155 .138 ? .130 .122 ? Rear Springs .312" .260 .240 .220 The .138" and .122" plates occur only in the 540 lbs. front springs. Firths wish to know whether these two thicknesses can be altered to one or other of the other 8 thicknesses of plates. This information should be conveyed to them if possible on Monday, 23rd inst. (j) As regards By15/P16.1.22, I have ascertained that the cast iron dies which Firths have so far made are expected by them to be suitable for any ordinary types of springs for which they may receive orders and not necessarily suitable only for our (contd) | ||