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).
Classification of springs based on poundage tolerances and defending departmental practices.
| Identifier | ExFiles\Box 67a\1\ scan0055 | |
| Date | 6th January 1926 | |
| - 2 - BY2/H.{Arthur M. Hanbury - Head Complaints} 6.1.26. --------------- These terms are explained and controlled by a chart in the hands of the Works, and the above means:- We divide springs at any point of poundage into:- 2000 lbs. (taking 2000 lbs. as an example.) 2005 - 2025 - plus. 2026 - 2049 - plus wide. 1995 - 1976 - minus. 1975 - 1950 - minus wide. and therefore no spring differs from actual poundage called for by more than 25 lbs. either way, but final axle clearances may and do vary plus or minus .250 as a result of dimensional errors in spring and chassis fittings. 2. I am quite positive in regard to the statement made against this in BY11/H.31.12.25. namely, that we have never, under any condition, departed from our formula on any of the chassis referred back to us by Sales. In every solitary instance the correction arrived at on the springing has been the result of either a variation on the body weight from that originally specified, or variation in passengers; generally both. If CWB. is still of the opinion that this sttement is wrong, will he kindly cite an instance. Personally, I am positive that my Department at least have never instructed springs for chassis except by formula. 4. In regard to the point I raise that by 11.12.25. only 14 sets of springs had been changed, this represents the facts of the case as distinct from conjecture. Since the issue is one which will affect matters definitely in the future, we can only go on actual facts, and not on conjecture. In this connection I would like to point out that before the War there was hardly a single chassis which was not back once, and sometimes twice, for spring modification, and that therefore, in view of this, our present position is very good indeed compared with what it has been in the past. Contd. | ||