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).
Continued engineering test procedure for skid pad testing on a chassis.
| Identifier | ExFiles\Box 155\4\ scan0059 | |
| Date | 30th April 1940 guessed | |
| E.R. 51. VAUXHALL MOTORS LIMITED SCHEDULE No. 216 SHEET No. 3. ENGINEERING TEST PROCEDURE CHASSIS SECTION SUBJECT SKID PAD TEST PROCEDURE (Contd). PREPARING FOR TEST RUN. Record the weight of the car on all four tyres, complete with equipment and crew as ready for test. This is mainly to ensure that the distribution of load is correct. Adjust tyre pressures. These should be maintained at 3 pounds higher pressure than the cold pressures intended, to approximate hot running conditions. It will be necessary to check up tyre pressures about every other time a stop is made for reading the theodolite, however no fixed rule can be laid down as tyre conditions depend considerably on the temperature of the skid pad, amount of sun etc. Car should next be positioned with its centre over the driving circle and the "sights" set to suit the driver. Next, roll the car outwardly and let it come back slowly. Following this with the car carrying its full complement of passengers, the theodolite should be set upon the tape on centre pole and the scales set at some convenient zero figure. Throughout the tests it will be found most convenient to adjust the theodolite by means of its vernier adjusters; they should therefore at this stage be set at the correct end of their travel so that the maximum number of tests can be completed without re-setting. As a further check to make sure the drivers "sights" are correctly set, the car should be driven as slowly as possible around the circle and under these conditions the pole should still remain central as seen through the theodolite. If the pole goes out of sight the car must again be set on the driving circle, the driver's "sights" rechecked, and the test repeated. MAKING TEST RUNS. The car is driven at a uniform speed around the skid pad with its centre as nearly as possible over the 108 ft. radius circle. The driver must keep the speed of the car uniform and at the same time hold it on the circle. The car speedometer should be used only as a guide to the driver. The actual speed is determined by stop watch timing of a complete lap of the circle. One observer rides beside the driver and records the Front Wheel Indicators, Steering Wheel Indicator and takes the stop watch reading. The second observer rides in the rear and adjusts the theodolite until as seen in the telescope, the cross hairs average the travel of the band on the pole at the centre of the circle. Signed ................................. Dated ................................... Approved ................................... | ||