Me 163 Ejection

I believe Ian Flemming lead the Commando raid on Walther works in Hamburg, though I doubt the perplexed technicians put up the kind of resistance he latter used in his 007 books.

The problem with the compressed air ejection seats was apparently one of weight though they saw service on the He 219 and Do 335. The pyrotechnic ejection seat of the He 162 certainly would have fitted into the Me 163B but by then the Me 163 was not in service.

The FW-190 evaluation test pilots at (Rechlin) apparently wanted an ejection seat due to a suction issue, this was ruled out on weight grounds and they ended up with explosive bolts to blow of the canopy instead.

An functioning ejection seat would have enormously increased the success of the luftwaffe in defense of the Reich; it would give those newbie pilots and extra set of lives to build experience. Your chances of escape if you were in a state to attempt an egress, according to Luftwaffe data, were twice as high.

H202 is why you can't carry clear liquids on an airliner.

The DeHaviland DH.108 swallow killed a pair of pilots, it was a tailess design. However it took irreversible hydraulic servo controls (to prevent pilot coupled oscilations) and the replacement of the blunt vampire nose (which caused a shock stall and a pitch up that induced the pilot coupled oscilations to fix the aircraft.

Siegfried said:

The DeHaviland DH.108 swallow killed a pair of pilots, it was a tailess design.

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Actually it killed three pilots: Geoffrey de Havilland Jr., Sqn Ldr Stuart Muller-Rowland and Sqn Ldr George E.C. Genders. Sadly, we must give the Devil his due...

Interesting, Siegfried. From what I've read the first use of an ejection seat was on the He 280 twin engined jet, wasn't it?

Ian Fleming didn't lead any commando raids; he was a naval intelligence officer. He was however on the board that chose the targets of the force of commandoes that he had control over, including the raid on Kiel. This was 'T-Force'. Perhaps his most successful suggestion that was undertaken was 'Mincemeat', better known as 'The Man who never was', but in his role in NID (Naval Intelligence Division), he was not an actual soldier.

Regarding the D.H.108, it was actually designed to investigate transonic flight for research for the Comet airliner, but provided much information in other related areas. The British actually invited firms to tender for a specification for a rocket powered interceptor based on their research with captured 163s, one of which was test flown as a glider only. This was Specification F.124T (Operational Requirement 301), to which Avro made a mock up of their delta winged Avro 720, which was favoured to take the production contract, but Saunders Roe completed their mixed propulsion S.R.53 interceptor, of which two were built and flown.

Much research was done by the British on rocket propulsion using HTP post war for thrust augmentation on conventional aircraft and aboard sounding rockets the British planned to build. Even the de Havilland Comet airliner prototype had pods between each bank of engines for the fitting of rocket engines for RATO purposes.

Sadly, we must give the Devil his due...

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Sigh... oh, if we must, then.

nuuumannn said:

My understanding of the suits the pilots wore were to protect them in case of fire as much as the HTP itself.

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The suits were made from PVC and would offer no protection in a fire.
They were essentially an early chemical protection suit and as you say were not particularly effective.
Cheers
Steve

Yep, from what I remember, that's what was written; they were practically useless! I do have to find my book and quote what was written. I can vaguely remember something about asbestos?

Capt. Vick said:

Actually it killed three pilots: Geoffrey de Havilland Jr., Sqn Ldr Stuart Muller-Rowland and Sqn Ldr George E.C. Genders. Sadly, we must give the Devil his due...

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I brought up the point of the Swallow since it is often said that tailess designs can't fly transonic. In fact the Swallow's issues were not related to the tailess design at all, they came from blunt nose shock stall, pilot coupled oscillations and in the case of Muller-Roland's loss it is believed electrical issues.

Of course the Swallow had much higher sweep than the Me 163.

nuuumannn said:

Interesting, Siegfried. From what I've read the first use of an ejection seat was on the He 280 twin engined jet, wasn't it?

Regarding the D.H.108, it was actually designed to investigate transonic flight for research for the Comet airliner, but provided much information in other related areas. The British actually invited firms to tender for a specification for a rocket powered interceptor based on their research with captured 163s, one of which was test flown as a glider only. This was Specification F.124T (Operational Requirement 301), to which Avro made a mock up of their delta winged Avro 720, which was favoured to take the production contract, but Saunders Roe completed their mixed propulsion S.R.53 interceptor, of which two were built and flown.
:

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Heinkel retained responsibillity for all ejection seat research, their test sled was removed from Rostok and was seen in a few 1950s movies. I suspect the He 280 would have been serially produced with an ejection seat.

Rocket interceptors offered one of the few ways of obtaining a high altitude interception. The Locheed bribary scandal may actually have spoiled the Luftwaffe's choice of the SR 53 rocket interceptor since this offered on of the few ways of getting to altitude fast enough to intercept those atomic bombers.

Siegfried said:

The Locheed bribary scandal may actually have spoiled the Luftwaffe's choice of the RS 53 rocket interceptor since this offered on of the few ways of getting to altitude fast enough.

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I've read something similar; the Luftwaffe were very keen on the SR.177 to Specification F.155, which was almost complete when the project was canned in 1957, but models in German colours were made. This aircraft was to be altogether more capable than the SR.53, but it was a victim of Duncan Sandys' '57 Defence White Paper, which stipulated that no more manned interceptors were to be built. The Germans did want a strike fighter, and the SR.177 was an interceptor, but Saunders altered the design to suit. Nevertheless it was all in vain; the Lockheed marketing team really were top of their game.

"It can catalytically decompose in contact with certain materials: brass is one incompatible material and it was this that caused the explosion of an experimental British torpedo; they had left a few brass fittings in the torpedo. Pay attention to material compatibillity! Stainless only! "

The Germans used aluminium vessels of high purity for T-Stoff I think. I know some modern (well relatively,when I was still a practicing chemist!) vessels are indeed of some form of stainless steel.

Steve

"The problem with the compressed air ejection seats was apparently one of weight though they saw service on the He 219 and Do 335. The pyrotechnic ejection seat of the He 162 certainly would have fitted into the Me 163B but by then the Me 163 was not in service."

There was also the problem of loosing compressed air pressure. Remp mentions this in his He219 book.

nuuumannn said:

I've read something similar; the Luftwaffe were very keen on the SR.177 to Specification F.155, which was almost complete when the project was canned in 1957, but models in German colours were made. This aircraft was to be altogether more capable than the SR.53, but it was a victim of Duncan Sandys' '57 Defence White Paper, which stipulated that no more manned interceptors were to be built. The Germans did want a strike fighter, and the SR.177 was an interceptor, but Saunders altered the design to suit. Nevertheless it was all in vain; the Lockheed marketing team really were top of their game.

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The fact that Lockheed paid out millions in bribes was what sold the plane. It wasnt known as the deal of the century for nothing Lockheed bribery scandals - Wikipedia, the free encyclopedia

fastmongrel said:

The fact that Lockheed paid out millions in bribes was what sold the plane. It wasnt known as the deal of the century for nothing Lockheed bribery scandals - Wikipedia, the free encyclopedia

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Yep, as I said, I'd read something similar. The fact that the British government weren't supporting their own industry left options closed for a lot of nations, though. An interesting contradiction to the Lockheed saga was the fact that the Royal Australian Air Force bought the Mirage instead of the Starfighter, because, according to one source I read on that purchase, Lockheed pretty much thought they had it in the bag, but they were out foxed by the French at the last minute.

Just re-reading that wiki link, interesting that the Saudis received money, but that they purchased the EE Lightning instead. That was the work of Scotsman David Stirling, who was responsible for helping establish the SAS during WW2. Fascinating man.

David Stirling - Wikipedia, the free encyclopedia

Now, getting back on topic regarding HTP (hydrogen peroxide): The following comes from (I think) Nicholas Hill, who did some research into British rocketry and published a book called 'A Vertical Empire':

"Hydrogen peroxide has the chemical formula H2O2. It is easily decomposed, and breaks down into water and oxygen:
2 H2O2 = 2 H2O + O2. A catalyst is used to make it decompose. One of the standard ways of preparing oxygen in a school laboratory is to drip a weak solution of hydrogen peroxide onto maganese (IV) oxide, MnO2. The Germans used HTP to drive the turbine for the fuel pump of the V2/A4 rocket. Calcium permanganate was used, although this resulted in a very messy exhaust.

The British discovered that a silver plated nickel gauze could be used as a catalyst - the HTP was pumped through the gauze and decomposed. It can be used as a monopropellant - that is, by itself - but this is not very effective. Since oxygen is produced in the decomposition, fuels such as kerosene can be burnt in addition.

One of the first HTP motors was built by the Rocket Propulsion Establishment, at Westcott in Buckinghamsire:
"The Gamma engine employs silver plated wire mesh as a catalyst. The catalyst has a life of about 2 hours whereas the engine has a life of 20hrs. Thus the design of motors is such as to permit the easy replacement of the catalyst. The motor is a simple combustion chamber with a flared outlet and having a restricted throat. HTP is pumped through the catalyst, where free oxygen and steam at around 500oC is produced. Kerosine is then pumped into the chamber in a finely divided spray, which is ignited by the heat of the steam. The temperature at the throat is of the order of 2300oC, while the temperature of the efflux is 1100oC. It will burn HTP alone but the thrust is halved." (December 1953)

HTP has a disadvantage that it is not the most energetic of rocket fuels. The effectiveness of rocket fuels can be measured by their Specific Impulse, or S.I. This can be thought of as the thrust produced per mass of fuel burned per second. In vacuum, the SI of HTP/kerosene can reach about 240, liquid oxygen/kerosene around 280, and oxygen/hydrogen over 400.

To offset this, it has features in its favour. Firstly, it is very dense. Its density is 1.48 times that of water; liquid hydrogen has a density of 0.08. This means that, weight for weight, liquid hydrogen occupies 17 times the volume, which means much bigger tanks and so extra weight. In addition, HTP is not cryogenic, and doesn't need the layers of inulation that liquid hydrogen tanks do. It does boil off on the launchstand either, which for cryogenic, fuels, can mean constant topping up of the tanks.

It was used a great deal on projects involving aircraft, and in service extensively with the R.A.F. From the crew point of view, this must have been by far the best choice of oxidant. All rocket fuels are hazardous, but HTP was easier to handle than most. It was not cryogenic. It did not give off any poisonous fumes. If any was spilled, it could quickly be washed away with a hose and water."

Interestingly, I visited the Science Museum's outstation at Wroughton in Wiltshire once and examined some of the rocketry hardware they have there and I was surprised to see that early British motors built post war had 'T-Stoff' stamped on the HTP lines! Very peculiar.

I believe the heat of the reaction when the H2O2 breaks down was such that the water was turned to steam and was at such a temperature that it would ignite the Kerosene. It did simplify the rocket ignition

The breakdown of H2O2 into steam oxygen was accomplished in the Me 163 using an aggregate concrete made with potasium permangenate solution. Walther still has a web site going! (sort of )

The Me 163A 'cold engine' worked purely of H2O2, exhaust steam but it was for testing only, as did the Hs 293 rocket motor. The Me 163B received the 'hot' engine with a fuel as well as an oxidiser.

Siegfried said:

The breakdown of H2O2 into steam was accomplished in the Me 163 using an aggregate concrete made with potasium permangenate solution. Walther still has a web site going! (sort of )

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Is this the website you mean, Siegfried? It's a very informative one put together by a very knowledgeable and pleasant English chap called Shamus Reddin. Well worth a read.

The Hellmuth Walter Rocket Motor Web Site

Shortround6 said:

I believe the heat of the reaction when the H2O2 breaks down was such that the water was turned to steam and was at such a temperature that it would ignite the Kerosene. It did simplify the rocket ignition

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Yep, it sure did; the British based a whole family of rocket motors on this basic principle.

nuuumannn said:

Is this the website you mean, Siegfried? It's a very informative one put together by a very knowledgeable and pleasant English chap called Shamus Reddin. Well worth a read.

The Hellmuth Walter Rocket Motor Web Site

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Yes: A CIOS report on Walther work developments here:
CIOS-XXVIII-53

Very interesting, if a little hard to read in places.