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).
Development and trial of shuttered bonnets, comparing them to louvred bonnets.
| Identifier | ExFiles\Box 119\3\ scan0051 | |
| Date | 23th July 1914 | |
| Wor{Arthur Wormald - General Works Manager}/Mcrs/L23714. RE SHUTTERED BONNETS. X.1085 J.{Mr Johnson W.M.} 23-7-14. Mr Royce in his memo R15/P 17.7.14 states that we have lately arranged to use 4 shutters instead of 2 as previously, and you have recently asked us (CJ10/IW20714) whether all cars are now fitted with Bonnets having shutters. In reply to your query we wish to explain that several cars in the Experimental Shop have been fitted with 2 shutters only; these were reported on by Mr Hives 11/3/14 and the results showed that such a Bonnet was not nearly so efficient as a louvred Bonnet. As a result of this Mr Royce suggested on 3/5/14 that we put shutters at each end for a trial, and we instructed the Drawing Office on 28/5/14 to issue such a Bonnet for experimental purposes, but until recently the only bonnet instructed by them was the one fitted to 58NA.{Mr Nadin} Warwick in his report on the running of this car says :- "The shutters make a slight difference "to the heat on the floorboards but "not to the boiling of water in the radiator" | ||