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).
Costs and benefits of different radiator tube designs and bonnet ventilation.
| Identifier | WestWitteringFiles\V\March1931-September1931\ Scan254 | |
| Date | 12th June 1931 | |
| HS.{Lord Ernest Hives - Chair} ) FROM R.{Sir Henry Royce} BY.{R.W. Bailey - Chief Engineer} ) C. to SG.{Arthur F. Sidgreaves - MD} WOR.{Arthur Wormald - General Works Manager} RG.{Mr Rowledge} C. to E.{Mr Elliott - Chief Engineer} RHC.{R. H. Coverley - Production Engineer} DA.{Bernard Day - Chassis Design} RADIATORS. COST OF TUBES. filed 84607. x7200 x5250. The dents in the tubes, and the thinner copper, all seem good, and make the main difference, which is great compared with the old model, and especially the less deep P. 1. type. We also get great improvement without much cost and weight from the non-spilling valve and bonnet ventilation. Then come the dents in the tubes, and most costly for money and weight is the difference between small and large tubes of nearly 2000 - i.e 33% on for 3 1/2° on a gain of more than 20° for the items which actually save money or cost little. Many complaints are from people without bonnet ventilation. Some would have been cured by the non-spilling valve as the loss of water was not through boiling. This non-spilling valve put up the barometer 4" of mercury, approx: 1° per inch = 4° for this non-spilling cap which has not been allowed. Finally I want to keep the enginehouse cool, (which the large tubes help because of ingoing air being cooler,) for volumetric efficiency, detonations, and floorboards and car being generally cooler, as well as the lubricating oil. So we gain by all the move so much for so little, and we lose and gain on the smaller tubes for much expenditure of money. We shall always have some just and some foolish complaints and it is the wisest course that will leave us in the best position. I vote for the larger tubes until experience shews that we are wrong, because we might suggest still smaller tubes and get another 2°. The weight saving is 23 lbs. for the smaller tubes and 37 lbs. for the larger (full of water) which is how we have to carry the somewhat delicate unit. The bonnet shutter we have suggested is extremely easy to operate, A push from the outside opens, and another at the other end (obvious) closes. There will then be no temptation to have louvres, or to have shutters and not open them. RECEIVED R.{Sir Henry Royce} 1931 JUN 15 H- | ||