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).
Letter to The British Thermostat Co. Ltd. regarding the failure of a thermostat during testing and requesting comments.
| Identifier | ExFiles\Box 156\1\ scan0236 | |
| Date | 12th August 1937 | |
| 1328 August 12th 1937. Rm{William Robotham - Chief Engineer}/Std.1/AP. The British Thermostat Co.Ltd., Teddington Works, Windmill Lane, Sunbury-on-Thames, MIDDLESEX For the attention of Mr.Martin-Hurst. Dear Sirs, We are returning to you one of the two B.G.A. 2073.A. thermostats, which you sent us recently after rectifying the opening temperature - it is the one with the 1 5/16" dia. seat. This thermostat was fitted to a car as soon as it arrived and functioned satisfactorily for about 30 miles, giving an average running temperature of approximately 82.5°C. After about 30 miles the car was driven hard for a stretch of about 2 miles to see what maximum the temperature would rise to - after rising slowly to about 85°C. it suddenly started to rise further and settled down at 90 - 92°C. - this temperature was maintained throughout the return journey under touring conditions. The thermostat was therefore removed and checked - it was found to commence opening at 47°C. and the bellows had cracked at the base of the bottom convolution, on the small diameter portion. We should like to have your comments on this failure as soon as possible as we are contemplating standardisation of these thermostat units in the near future, and understood that they were absolutely reliable. Further, we would like to know why the bellows when punctured, returns to a closed position - you have given us to understand that when punctured the bellows would remain partially open. Finally we should like this 1 5/16. dia. thermostat repaired and returned to us at the earliest possible moment in order to complete our tests. Yours faithfully, FOR ROLLS-ROYCE LTD. | ||