Jet pods page 4 alternate history discussion g gas lol


Sir Robert McLean, chairman of Vickers Aviation advised Reginald Mitchell "Better to design a ‘killer’ fighter in advance of any Ministry specification. In no circumstances would any technical member of the Air Ministry be consulted or allowed to interfere with the designer."

The chairman of the company that built the Wimpy, and the Jockey, doesn’t sound like he has faith in the foresight of Ministry personnel when he suggests "Build it and they will buy it’. The Hurricane and Spitfire began as private ventures, powered by an engine called PV12. You know what PV stands for. Freeman’s Folly would have been another example, had it not been for one exception.

I have no doubt that Britain possessed the talent to design and build jet aircraft but I doubt that it had talented design engineers wealthy enough to do it on their own. I look at the encouragement given to one James Martin, who never realized that he would never receive a contract for production aircraft because he wasn’t on the approved list. Fortunately, he decided to seek alternative avenues of endeavour, after the unfortunate death of his partner. But that’s another story.

After surveying the situation, Whittle decided that another major reconstruction would be necessary. He abandoned the original concept of a single big combustion chamber, and produced a totally new layout incorporating ten small chambers. These conformed with the then-existing ten discharge ducts from the compressor. It soon became evident that this idea would make a much more compact and lighter engine. Though he had proposed multiple combustion chambers in his first patent he had avoided them hitherto, because of the rather elaborate ignition arrangements required to ensure that all the chambers lit up properly. It was obvious that if something went wrong, and one of several combustion chambers failed to light up, or if one or more became extinguished, the effect could be very damaging. While looking into this problem he hit on the idea of interconnecting tubes, by means of which each combustion chamber would light up from its neighbour, so that it would be necessary to provide initial ignition in one chamber only. He actually provided it in two chambers, as an additional safeguard against a starting failure.

This new arrangement received the general approval of Bramson, BTH engineers, Constant (who was working with Griffith at RAE on their turboprop project), and the DSR. Constant, like Whittle, was a little uneasy about the ten combustion chambers, but thought that Whittle was following a promising line and deserved increased financial support from the Air Ministry. Constant had been present at an engine test run on 23 August 1937, and had been very impressed. Whittle had maintained fairly good contact with both Constant and Griffith, but had only a slight knowledge of the RAE’s own work on gas turbines. This was because it would have been most improper for secret work done by a Government Department to be disclosed to a private company. Whittle had no complaint about this state of affairs, but thought it probable that Power Jets’ work was an important factor in stimulating this work at the RAE — and how right he was!

He had, however, suspected that the Air Ministry had a natural preference for such work to be done by the RAE rather than by an upstart private company. While the new combustion arrangement was being discussed, Constant told Whittle that he believed that the Air Ministry intended to request that BTH put Power Jets’ work on high priority. He also said that the RAE had already requested Firth Vickers to give Power Jets a high priority on supplies of special steels. It appeared that Constant, at least, was not allowing his RAE work to influence his true judgement as far as Power Jets was concerned. On 30 May 1938, on the advice of Bramson and Whittle, Whyte agreed that they should proceed with the new reconstruction. Fortunately, inspection had revealed that, with a little ingenuity, much more of the engine was usable than had seemed likely immediately after the breakdown.

Tests on a single combustion chamber verified that the interconnecting tube arrangement would work, and that ignition would spread from one combustion chamber to another as intended: “We did not realise it at the time, but the apparatus we used was very similar to the successful combustion system later developed after many heartbreaking disappointments. This was not the first time that we had been near the design which was ultimately to prove successful slight adjustment might have made all the difference, and could possibly have saved at least three years in the development of the turbojet”. (This seemingly amazing fact is typical of all really big steps into the unknown.)