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).
Letter to R. W. Dorey discussing the test results of Esthonian Shale Spirit, deeming it unsuitable as an aviation fuel.
| Identifier | ExFiles\Box 27a\4\ Scan058 | |
| Date | 7th February 1933 | |
| R.{Sir Henry Royce} W. Dorey Esq., Rolls-Royce Ltd., Nightingale Road, DERBY. 7th February 1933. Dear Dorey, Very many thanks for yours of the 6th February. I am very sorry, but I am afraid I must call my trip to Derby off, as I have to go to Germany on Thursday and I already have an appointment for tomorrow. We have just received the results of the tests on the samples of the Esthonian Shale Spirit which you sent us. These tests, in our opinion, practically rule it out as an aviation spirit. Incidentally the two samples are practically identical and one did not contain 30% of benzol as you suspected. Commenting on the samples; the sulphur content is very high and would not meet any government requirements for an aviation spirit. In fact, the sulphur content is about 3 1/2 times higher than the limit imposed in most fuel specifications. The gum content is low, but there is an appreciable amount of peroxides present. It is our opinion, that the reason for the low response to the addition of tetraethyl lead is due to the presence of the peroxides. The Octane Number of the spirit at 212°F is 67.5 and at 300°F is 63. The addition of 3 c.c.'s of "lead" per gallon brings the Octane number only to 69. This is about the poorest spirit as regards "lead" response that I have come across. It will, therefore, be impossible to reach the Octane number you require with "lead" alone and it seems that if you go to benzol too much will be required and this will upset the freezing point. Most aviation spirit in itself is "straight" run and in any case contains a relatively small proportion of olefine hydrocarbons. This spirit, however, has an olefine content in the neighbourhood of 70/80%. In any case, I do not suppose you want to use a spirit which has such a high sulphur content. I am attaching herewith a copy of the complete tests carried out on the two samples. It would be better if you did not notify the Esthonian people that you | ||