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 discussing the performance and reliability of fuel gauges and comparing them to the K.S. Hobson Telegage.
| Identifier | ExFiles\Box 44\4\ Scan156 | |
| Date | 13th January 1930 | |
| Returned to Mr Rowbotham X4038 ROLLS-ROYCE OF AMERICA, INC. SPRINGFIELD, MASS. OY-2 Jan. 13, 1930 RECEIVED 25 JAN 1930 Mr. E.W. Hives, Rolls Royce, Ltd., Derby, England. Cc- Mr. R.W.H. Bailey Mr. B.I. Day Mr. A.G. Elliott Mr. Southern Mr. Burton Mr. Soutter Dear Mr. Hives: K.S. Hobson Telegage Having gathered that you were not perfectly satisfied with the performance of the fuel gauges I had a discussion of the matter Jan. 10th with Bandemer, Ch-engineer of the K.S. Company and made the following notes which may interest you. The subject is of interest to us as we are going to try to persuade you that a twin instrument board gauge showing fuel and oil level is a desirable improvement in our cars, and you are not likely to believe this unless we can demonstrate that complete reliance can be placed on both gauges. Our own fuel gauges are not perfectly reliable, the reading tending to be low on standing after a long run. They are not fitted with an air pump or with a pressure balance line. Except for the above defect which may cause a low-reading of as much as 3 gallons (U.S.) they are reliable when correctly installed. The installation is simpler than yours because only two joints have to be made at coach-works, instead of six. We have not noticed any error in reading at speed due to different air-pressures at the gas tank and at the instrument, i.e. we do not find the pressure-balance line necessary. Because of variable "wind pressures" due to rotating cranks, the oil-level gauges are fitted with a pressure balance line but not with a pump. The lower volatility of the oil causes very little variation in level of the gauge due to cooling-off effects, as compared with fuel. - continued - | ||