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).
Comparing the chassis weights of the Wraith model against the 25/30 model and experimental cars.
Identifier | ExFiles\Box 109\5\ scan0238 | |
Date | 21th March 1938 | |
SECRET. To EY. from SG.{Arthur F. Sidgreaves - MD} Copy to Mr.Rm.{William Robotham - Chief Engineer}Cr{Mr Cra???ster / Mr Chichester} re Wraith Chassis Weights. I do not seem to remember having heard very much about this in the past from the point of view of what we expected the weight to come out at as compared with the 25/30. JLE{J. Lee Evans - Chassis Test Manager} has weighed two chassis Nos.WXA.20 and WXA.27 and finds that the average weight is 28 cwt. 1 qr. 21 lbs. which includes petrol, oil, water, battery, front bumper, spare wheel, tyre and bracket, Seapack, body bolts, brackets, etc., lamps, spares and tools. He says that the 25/30 chassis under similar conditions weighed 27 cwt. 1 qr. 7 lbs. which did not include a front bumper the weight of which is 25 lbs., making a total of 27 cwt. 2 qrs. 4 lbs., which indicates that Wraith is nearly 1 cwt. heavier than the 25/30. We have turned up some weight analyses of experimental cars as given by W., which give the weight of the chassis including petrol, oil, water, spare wheel etc. but excluding front bumper, Seapack, lamps, tools and horns, as 26 cwt. 2 qrs. 11 lbs. Allowing for the items mentioned as being excluded from this weight, the above figure would be 27 cwt. 1qr. 14 lbs., i.e. 1 cwt. - qr. 7 lbs. less than JLE{J. Lee Evans - Chassis Test Manager}'s figure of 28 cwt. 1 qr. 21 lbs., which would indicate that the production chassis are comingout about 1 cwt. heavier than the experimental ones, which one can hardly believe. Nevertheless I find that, when I first had my car, I recorded in Sg{Arthur F. Sidgreaves - MD}14/E21.3.38 that, after making a very careful comparison between the weights of the two cars with exactly the same things on, the new car was 1 qr. 21 lbs. lighter than the old one and I can hardly imagine it would have been if the chassis had been 1 cwt. heavier. Although I realise that Wraith gives a bigger body space, this is largely achieved by pushing the engine further forward and, if the weights given by JLE{J. Lee Evans - Chassis Test Manager} are -as I imagine- correct, I am wondering whether Derby are satisfied with the result which means that, after a design interval of some 15 years we are going to market a car of equivalent HP, the chassis of which is about a cwt. heavier. | ||