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).
Water leak issues with evaporatively cooled 'Kestrel' engines in the 'Southampton Flying Boat'.
| Identifier | ExFiles\Box 179\2\ img005 | |
| Date | 1st December 1931 | |
| ORIGINAL To R.{Sir Henry Royce} From Hs.{Lord Ernest Hives - Chair} c. to Sg.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} c. to Rg.{Mr Rowledge} H.{Arthur M. Hanbury - Head Complaints} c. to By.{R.W. Bailey - Chief Engineer} Hs.{Lord Ernest Hives - Chair}2/WJ.1.12.31. X.4657. X.2444. 'KESTREL' ENGINES EVAPORATIVELY COOLED. The 'Kestrel' engines which are running in the "Southampton Flying Boat" under evaporatively cooled conditions have given considerable trouble with water leaks at the rubber joints. The results on this machine are sufficient to say that we are not yet in a position to recommend our present engines as being satisfactory under evaporatively cooled conditions. The trouble appears to be that with the increase in temperature the rubber ring becomes vulcanized and loses its resiliency. One proposal is that we shall use rubber rings which in the manufacture have vulcanized to a higher temperature so that they will stand more heat. Rings of this type are being fitted to No.39 engine, which is to run a Type Test under evaporatively cooled conditions. The trouble is aggravated by the fact that experience has shown us that the rubber joints cannot be fitted tightly. The most satisfactory engine which has been running under evaporatively cooled conditions, is the one fitted to the Fairey "Fox" machine which has been used for all the development of the Fairey evaporatively cooled system. This engine has flown for 70 or 80 hours without any trouble. The interesting feature about this engine is that it is fitted with cylinders with forged spectacle plate at the base of the cylinders. This means that the engine would have tighter rubbers than the present standard, and this is the reason why we consider this engine has been free from leaks. It would appear advisable therefore to revive cylinders with forged spectacle plates. We are still not free from failures of cylinders cracking between the bores. During the last two months five cylinders have failed from this cause on engines on test. There are one or two moves in hand, such as the raised floor block, and increased clearance between the steel liner and aluminium block, which we hope will reduce this trouble. On evaporatively cooled engines, however, where we have got to expect to work with 7 or 8 lbs. pressure in the blocks we believe we shall find that it will be essential to use tighter rubbers which may increase our difficulties. The Foundry have difficulty in ensuring that the material in the bridge piece is free from oxide. There are a large number of machines being installed with evaporatively cooled systems, which means that we have got to give considerably better reliability than we have in the "Southampton Flying Boat" before any of these types could be accepted as satisfactory for service. -''- | ||