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).
Manufacturing challenges and supply of thermostats and bellows.
| Identifier | ExFiles\Box 156\1\ scan0099 | |
| Date | 20th May 1935 guessed | |
| - 2 - Messrs. Rolls-Royce Ltd. We agree that you do not specify a definite temperature range, merely stating that it must not exceed 7°. We have already given you our recommendation for the minimum length of bellows to be employed to obtain such a minimum temperature range, and you have informed us that it is impracticable for you to follow our advice. (2). In your letter of May 15th, you point out that the 15 thermostats, EB. 667, supplied to an earlier order, dictated your requirements in the case of thermostats E.{Mr Elliott - Chief Engineer} 86612. We have already told you that we might not be able to supply you with any number of thermostats having identical characteristics due to the uniformity of any one batch of bellows. The fact that a particular batch of bellows, when built into identical assemblies, gives identical results, speaks well for the uniformity of manufacture, but we are not prepared to guarantee to be able to reproduce precisely the same conditions in the next batch of similar bellows. You will see, therefore, that the fact that you have already had one uniform batch of 15 assemblies, does not necessarily make it practicable to produce further quantities of the same unit having identical characteristics. It interests us to hear that a competitive firm are of the opinion that they can produce the thermostat which you require as a production proposition. We can only say that it would appear that our competitors have either under-estimated the difficulties or over-estimated their ability to overcome them. We are the last people to suggest that a thing is impossible, if we can see any way of doing it. We do, however, always try to obtain any result in the simplest and most satisfactory manner, and our comments and suggestions in connection with this matter have all been based on this principle. (3). The function of a thermostat of the type under discussion | ||