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).
Cause of loose brake brackets on the rear axle of the 4.EX Car.
| Identifier | ExFiles\Box 49\1\ Scan313 | |
| Date | 23th May 1921 | |
| X4063 To EWT. for R.R. Inc. attention of OY. from Hs.{Lord Ernest Hives - Chair} c. to OY. c. to R & E.{Mr Elliott - Chief Engineer} Hs{Lord Ernest Hives - Chair}1/LG23.5.21. X4063 X3764 BRAKE BRACKETS ON REAR AXLE. Referring to Mr. Olley's memo OY8/G25.4.21. We feel confident that the cause of the brake brackets coming loose on 4.EX Car is nothing to do with the operation of the brakes. Mr. Olley will remember that on the ride from Buffalo to Cleveland the car was scraping along frozen snow drifts and that it eventually got stuck with the rear axle casing supported on the frozen snow; the rear wheels running round freely in the ruts. When the car is on the maximum bump, the brake brackets are only .375" higher than the bottom of the rear axle casing. We, therefore, suggest that the reason the bolts on the brake brackets failed was due to these brackets supporting the weight of the rear part of the car. The shape of the rear axle casing would allow it to plough its way through any obstruction; the brake brackets however, would dig in. One would expect the ground to be higher close against a rut than it would be in the centre of the rut. The fact that the car was driven well over 1000 miles after that happened and that the loose brake brackets were only discovered when the car was being overhauled, shows that the load on this bracket due to the braking effort, is very little. There are running about considerably over 150 R-R Cars with the brake brackets fitted in this manner. Most of these cars are Armoured cars which are used on very bad roads and the brakes are used most severely contd:- | ||