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).
Failures and proposed modifications for the 20/25 HP chassis wind tone horns.
| Identifier | ExFiles\Box 59\3\ Scan378 | |
| Date | 9th January 1936 | |
| E/EV.{Ivan Evernden - coachwork} c.c. HS.{Lord Ernest Hives - Chair} By.{R.W. Bailey - Chief Engineer} Dy{F R Danby}/RD. Hs{Lord Ernest Hives - Chair}/Wst. E.1/HP.9.1.36. 20/25 HP. Chassis Wind Tone Horns. The wind tone horns fitted with the double spring steel concentric brackets have a very easily excited natural period which is obviously the cause of the brackets fracturing. Will you please instruct forthwith a single thicker bracket say equal to the combined thickness of the present double one, and we will try the effect of the note on the car - 21-G-IV. Some attention is required to the wiring of this horn. There is a long piece of unarmoured cable used at the moment the cover of the horn being twisted round to prevent rain driving into the slot. The insulation of this wire frays through and causes a failure due to damage caused by the cover slot having a sharp edge. It should be possible for the cable to pass in underneath, through the base of the horn protected by a suitable round edged bush instead of passing through the cover, as suggested by Hs{Lord Ernest Hives - Chair}/GWH{George W. Hancock - Head Chateauroux} and not through the sheet metal cover on the top of the horn at all. Also armoured cable should be used and arranged with the minimum length exposed. Presumably fraying is taken care of at the lamp standard by radiusing the edges of the hole. E.{Mr Elliott - Chief Engineer} | ||