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).
Failure and proposed redesign of the 20/25 HP & Bentley flexible blade fans.
| Identifier | ExFiles\Box 104\3\ scan0227 | |
| Date | 15th May 1936 | |
| To RHC.{R. H. Coverley - Production Engineer} x 5V4 Hs{Lord Ernest Hives - Chair}/Std.4/JH.15.5.36. 20/25 HP. & Bentley Flexible Blade Fans. We received one of these fans over 2 months ago and after 10 hours endurance on the test beds a crack developed in one of the blades. The fan was then rebuilt using a stiffening strip to prevent localisation of stress, but again failed owing to the form of the stiffening strip acting as a guillotine and cutting through the blades. We therefore asked RHC{R. H. Coverley - Production Engineer}/WEB. approximately 6 weeks ago to rebuild this fan, (only the blades were damaged) omitting the stiffening strip and putting a radius on the aluminium packing piece which holds the blade. We have not yet received the rebuilt fan. We are having complete success with the form of construction used on the Ph.III type of flexible fan (we now have two of these running) and therefore would like you to scrap the present flexible 20/25 fan and build two with exactly the same construction as the Ph.III using .012 blades on one, and .014 blades on the other (this material is in the stores). This will of course necessitate new details. Hs{Lord Ernest Hives - Chair}/Std. | ||