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).
Description of the 'Bumping Rig' test apparatus used for simulating extreme road conditions on car chassis.
| Identifier | ExFiles\Box 119\2\ scan0367 | |
| Date | 12th October 1932 | |
| X4268 12.10.32. R.R. BUMPING RIG. You are now listening to the noise made by a test apparatus designed by Messrs Rolls-Royce to subject car chassis to treatment far exceeding the worst possible road conditions. The rear wheels of the chassis are secured by cast iron blocks embedded in the concrete floor, and which are positioned so that the front wheels of the chassis lie on the crown of two massive four feet diameter drums which are sunk so that the crown is level with the ground. As these drums are turned by a powerful motor, the front wheels rotate. Projections on the drums strike the wheels blows which are equivalent to the worst type of pot hole. The road wheels receive 210 of these blows per minute. For tests on the rear of the chassis it is necessary to put the back wheels of the chassis on the drums and secure the front wheels to the cast iron blocks. You can distinctly hear the projections hitting each wheel in turn, and also the twist of the chassis as it receives the blows. 10 hours of this battering has been found by experience to produce failures which normally would not occur under less than 10,000 miles of road work. Every new design of axle, steering gear, shock absorber, frame, radiator, or wheel, must withstand 100 hours of this gruelling before being regarded as fit for production. Improvement in material is such that road springs only used to last 12 - 15 hours on this test, but now they have a life of over 50 hours which is equivalent to almost an infinite period under the worst colonial conditions. Two of these rigs are kept running to improve the quality of R.R. cars. When chassis components have passed the bumper test they are considered fit to undergo a 15,000 miles road test. Besides proving the strength of parts, these test rigs enable Messrs Rolls Royce to examine closely the functioning of every part of the chassis under various road conditions. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||