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).
On the design and testing of special snow chains for the P.III, Bentley, and 25/30 HP models.
| Identifier | ExFiles\Box 128\3\ scan0171 | |
| Date | 17th March 1937 | |
| Sg.{Arthur F. Sidgreaves - MD} from Rm{William Robotham - Chief Engineer}/PD. Hu. E.{Mr Elliott - Chief Engineer} By.{R.W. Bailey - Chief Engineer} Ev.{Ivan Evernden - coachwork} Da.{Bernard Day - Chassis Design} Gx. Hn.{F. C. Honeyman - Retail orders} ✓ 1109. RM{William Robotham - Chief Engineer}/PD.1/AP.17.3.37. RE. SNOW CHAINS FOR P.III, BENTLEY AND 25/30 HP. Owing to the close proximity of the cross steering tubes to the tyres on the P.III., we have been unable to fit the standard type of snow chains as supplied to the general public, also as a large percentage of our customers use discs we were not able to recommend the use of strap chains. With the assistance of the Parsons Chain Co., we have designed a special chain which rides high on the inside of the tyre and so clears the steering tube ball end. It is essential when fitting this new chain to clip in the first hook on the inside of the chain and to always take up the adjustment on the outside where 2 fastening clips have been provided. We have also supplied additional springs and clips to keep the chain in tension and to take up the slack, these spring adjusters also make the chains very much quieter in operation. A pair of ladder type chains, and a pair of de luxe chains were obtained to this new specification. The latter type are to be recommended as the life of the chains will be 100% longer due to each cross link having a bar welded across. Both sets of chains have been tested and we have covered approximately 250 miles, 60 miles of this was run at speeds between 50 - 55 m.p.h. to see if the chains tended to move round the tyre, however, we found this was quite satisfactory, the chain tensioners keeping the chains in position. A further test was made with one of the cross chains cut in two, the object of this was to see if the chains would foul the steering tube due to a breakage. Whilst the driver is quickly warned of a cross chain breakage due to the chain ends hitting the mudguard tip, we should be quite safe with regard to any of the chain jamming the steering. continued | ||