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 a central sphere failure on car 1825, attributing the cause to reckless driving.
| Identifier | ExFiles\Box 77\1\ scan0109 | |
| Date | 21th May 1912 | |
| Copy. 21.5.12. Re Ferguson's car 1825. Central sphere failure. After a creful examination of parts I consider this breakage was due to reckless driving so much so that the propeller shaft actually fouled the inner central sphere, caused outer sphere to break, due to excessive movement of axle relative to frame caused by car being driven across a culvert at full speed. I have since tested a sphere exatly similar and loaded it as per sketch "A" to 2 tons, finding no deflection, and then loaded it as per sketch "B" with 2 tons which load it sustained for some 30 minutes, but broke when struck with a mallet. The maximum load due to driving reaction on ball is 500 lbs on slow speed with engine developing max torque, but as the footbrake is very powerful it could impose a load of 1000 lbs on ball as a factor of safety of 4.5 to 1 is shewn. So that I consider the breakage is due to reckless driving. I am however, inclined to think that the Phos. Bronze we make the ball frames is rather too hard and there-fore inclined to be short and sudden in failure, to try X 628 | ||