Part of the stash of material I obtained that started this thread has yielded some real gems. There are a number of files and folders, including this that was an envelope, a single picture and three pages of typewritten material, obviously an article.

I shows something that frankly I did not know about – UK companies were using German locations as soon as the war in Europe had finished. I knew that some material was taken to Thurleigh and used there for aerodynamic research, but not that before that, we were taking material over there. Sadly, I do not know who wrote the article, or who took the picture.

During the war, Munich and its surroundings were several times heavily bombed. The Bayerische Motoren Werke at Oberweisenfeld in the locality suffered considerable damage during these operations, but when this area was overrun by the Allied armies in 1945 it was found that the special high-altitude test plant for aircraft engines situated on the northern boundary of the B.M.W. factory was still in use.

Building had been commenced in May, 1940, and heavy bomb damage had been sustained in May, 1944. It had, however, been repaired by October of that year and from then until the collapse of Germany in 1945 the plant had been in regular service.

This plant is in the American occupation zone, but arrangements were made by the Ministry of Aircraft Production for its use by British manufacturers, and both the de Havilland Engine Co., Ltd., and Rolls-Royce, Ltd., were given facilities for testing engines there.

The de Havilland Company were approached by the Ministry of Aircraft Production in July, 1945, and after a preliminary survey of the plant by one of the company’s engineers, arrangements were at once made to test the Goblin I jet unit in the plant.

At present no other facilities exist for testing engines under conditions comparable with those obtainable at Oberweisenfeld. The test cell has a diameter of 12ft and can be evacuated to pressures simulating conditions at a height of 50,000 ft. Air can be supplied to the intakes at a speed of 550 m.p.h. and temperatures as low as —65 deg C can be maintained.

A special mounting for the Goblin engine was necessary but all the essential equipment and arrangements for the test were completed within twenty-one days. Another period of fourteen days was required for installation at the plant. A series of tests was then made at different speeds and under conditions corresponding to altitudes ranging from ground level to 43,000ft. The tests were completely free from trouble of any kind, though, owing to the very heavy power consumption of the plant, it was possible to operate it only at night.

The complete series of tests on the Goblin I required a total of 42 hours’ running and the engine was not examined until the tests had been completed. After being returned to England, the unit was re-calibrated and the output was found to be substantially the same as before. When it was stripped, however, inspection showed that a great deal of dust had been drawn in from the heavily bombed area which surrounded the test plant and a certain amount of superficial damage thereby caused.

The success of the tests and the value of the information obtained led to the decision on the part of the de Havilland Company to undertake a second series, this time on a Goblin II engine. These tests included observations of combustion and flame stability at altitude, and engineers from Joseph Lucas, Ltd., took part.

Normally, the method of observing the engine during test was through a periscope in the side walls of the cell, but for the purpose of these special combustion tests quartz windows were inserted in a flame tube of the engine and windows were cut in one of the explosion doors at the top of the test cell. Gas samples were also taken from the exhaust by the Lucas engineers. During the tests the inside of the cell was brilliantly illuminated and formations of fog and ice under high-altitude conditions could be readily observed. In taking measurements of the engine thrust it was found necessary to supply glycol to the sliding joints to prevent them from freezing up.

The plant itself ran extremely well and was remarkable for flexibility steadiness and stability under all operating conditions. The Siemens automatic control system, housed in a separate room, is of outstanding interest. In spite of its complexity it is surprisingly reliable. Constant altitude conditions are maintained irrespective of the air consumption and the test engineer is therefore relieved of all anxiety on this score.

Be Reithian with giving people data that may stretch them, rather than telling them stuff they already know –

I trained as a Tool Designer/Toolmaker so from my own point of view I understand what I’m looking at. It would not bother me in the slightest explaining how metal drop-tanks were made as half-shell single pressings on a 1500-ton hydraulic press from 23 SWG steel sheet – and showing both the production line process that allowed for both spot-welding of the internal baffles and continuous welding that was done automatically at a rate of 60 inches a minute.

I got all the pictures to do this – probably about a thousand – but yesterday I had John Hamlin from Air Britain and ARG over and was showing him some – John knows his aircraft, but the glazed eyeball syndrome soon struck!

This is why I made the enquiry to attempt to strike the right balance!

The Comet 1 certainly had them – two underwing points that allowed pumping at 150 gallons a minute.

I got a memory somewhere something like a SAAB was earlier… but I cannot find my note.

Oh well!

I sort of got the dimensions wrong – it is four feet by EIGHT feet!

This is what it is!