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).
Investigation into failures of faulty Smith electric petrol gauges in the Test Department.
| Identifier | ExFiles\Box 61\3\ scan0358 | |
| Date | 28th July 1933 | |
| 84523 By.{R.W. Bailey - Chief Engineer} From Hs{Lord Ernest Hives - Chair}/Wst. c. to Mx.{John H Maddocks - Chief Proving Officer} c. to Sft.{Mr Swift} Hs{Lord Ernest Hives - Chair}/Wst.6/MA.28.7.33. FAULTY SMITH ELECTRIC PETROL GAUGES. We have been investigating the various failures of the above which have occurred recently in the Test Dept. The trouble with the instrument board meters is as follows :- In the case of one instrument in which the needle was sticking, this was found to be due to the pivot support being distorted. The other meter which failed to record the correct petrol in the tank, was found to have a fault due to a defective soldered joint, between the control coil and the deflecting coil. This latter defect would only become apparent when the instrument was subjected to vibration as when fitted to a chassis. With regard to the petrol tank unit which failed recently, this was found to have a part of the potentiometer winding burnt out which could easily happen if the connections to the potentiometer were connected up wrongly on the chassis. The normal current through the coil is insufficient to affect the windings. We should be glad if precautions could be taken on production to see that it is not possible for the petrol tank unit wires to be connected up wrongly. We cannot blame Messrs.Smiths for this latter fault as there is no evidence to show that the instrument was not correct when it was received from Messrs.Smiths who carry out very careful tests on these instruments before they are despatched to us. One of the failures to the instrument patch meters as quoted above may have been due to damage in transit from Messrs. Smiths to our Works or in handling the instrument at our Works. | ||