#1 Strategic Target in WW-II Germany

The engines of the Luftwaffe needed high octane fuel. That is gasoline with the addition of very small amounts of tetraethyl lead and ethylene dibromide. A engine build for high octane gas usually will not run at all by normal gas. It will destroy itself after some seconds. Engines of today are not adabtable, those of WW2 probably not too. There was no substitute than and small stocks only. Without its special fuel most of Luftwaffe would be grounded.

Only German production sites:

- Tornesch near Hamburg, only ethylene dibromide factory - Gapel near Berlin, 100 tons tetraethyl lead per month - Frose near Magdeburg, 300 tons tetraethyl lead per month

At least two of this factories, probably all three, were build by Americans in the late 1930s. Under the ok of the US War Department.

Why were this factories never attacked?

Sources: USSBS, OMGUS

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U.S. STRATEGIC BOMBING SURVEY: OIL DIVISION REPORT GENERAL SUMMARY

Without tetraethyl lead, the octane number of the Luftwaffe's aviation gasoline would have been so low that a 2,000-hp fighter engine would have been able to deliver only 1,200-hp in the pinches - inadequate against Allied planes.

Tetraethyl lead, with all production prior to 1939 centered in one plant, was too scarce and concentrated for comfort. A second plant was built, coming into operation in July, a French plant was captured, and a third German unit was scheduled for completion in 1945. An underground plant was also planned, but no equipment was ever installed. The stockpile of tetraethyl lead in September, 1939, was equal to just 1.8 months war requirements. [!] Ethylene dibromide, a vital ingredient for ethyl fluid, manufactured in only one plant.[!!]

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USSBS Appendix A. Strategic Air Attack on the German Chemical Industry

Tetraethyl Lead

Importance and Uses

Tetraethyl lead was unique in the German war economy. While the volume of its production (400 tons per month) was only a drop in a bucket, its direct importance to the Wehrmacht and Luftwaffe ranked it among the most valuable chemicals.

Tetraethyl lead is the active ingredient of ethyl fluid (called Fluidin in Germany) which in used to improve the performance of aviation gasoline. Without ethyl fluid, the 'performance number' of German aviation gasoline would have dropped from 150 to approximately 90, and the power output of their airplanes would have dropped in about that ratio. A gasoline-fueled plane engine, originally able to deliver 2,000 hp in the pinches, without tetraethyl lead could deliver only about 1,200 hp. Since the use of te traethyl lead requires the addition of a corrective agent, ethylene dibromide, both these materials will be considered simultaneously.

The Germans made an aviation ethyl fluid of the same composition as that made by the United States (one molecule of ethylene dibromide per molecule of tetraethyl lead) and used it in about the same concentration.

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Plant Location and German Production

Germany had only one ethylene dibromide plant located in Tornesch near Hamburg. This had sufficient capacity to take care of requirements, and its production was adjusted to correspond to tetraethyl lead. Failure of ethylene dibromide production in October and November, 1943, was caused by an accidental fire, and production thereafter was accelerated to make up the deficiency. In spite of this vulnerable position, Germany apparently never considered the construction of a second ethylene dibromide plant.

Two prewar plants made tetraethyl lead in Germany: one at Gapel near Berlin, with a capacity of 100 tons per month, and one at Frose, near Magdeburg, with a capacity of 300 tons per month. Gapel was a peacetime plant built in 1936, whereas Frose was built secretly in 1938 to take care of wartime requirements.

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In the early stages of the war, capacity was insufficient to keep up with the expected increase in requirements.

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The Germans also used, beginning in March, 1942, the French tetraethyl-lead plant at Paimboeuf, in spite of its vulnerable position on the Atlantic coast. It had a capacity of 200 tons per month, but operating difficulties, primarily passive resistance by the operating staff, kept production down to 26 per cent of capacity.

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Consumption closely approximated production, and the stocks remained substantially constant with a backlog of about 6 months' consumption until March, 1944, when consumption began to exceed production. After July, 1944, decline in production showed the effect of the bombing of the ethyl chloride plants supplying this raw material. The slight increase in stocks after August, 1944, was not due to an increase in tetraethyl-lead production, but rather to the fact that the production of gasoline (and hence the use of tetraethyl lead) was deteriorating even more rapidly.

This industry was particularly vulnerable to air attacks. Both tetraethyl lead and ethylene dibromide plants handled highly reactive and inflammable materials. Both used special equipment which would take several months to replace. Part of the ethylene dibromide equipment was very fragile.

Germany depended entirely on only three small plants for its total requirements.

The industry was never attacked specifically. A few bombs were dropped on Gapel once, as a secondary target, but no damage resulted. The industry nevertheless felt the impact of the air offensive, and had to cut back production for lack of necessary raw materials.

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O.M.G.U.S. Office of Military Goverment for Germany, United States Finance Division - Financial Investigation Section [Investigation against the I.G. Farbenindustrie AG] Ermittlungen gegen die I.G. Farbenindustrie AG - September 1945 - [German Translation and Commentary, Noerdlingen 1986] ISBN 3891900198

Page 41: End of August 1938 I.G. Farben sucessfully got on request of the Air Ministery 500 tons tetraethyl lead from an american company. It was not bought but 'on loan only' by a 1 million dollar pledge. Source is at page 450, Ref. 22: 'Ethyl Export File' Summary only. According this file Germany had still no production of tetraethyl lead in 1938 and wanted to be independent from imports by 1939. Time of treaty and delivery is unclear. A letter from US Ethyl Export Corporation to I.G. Farben from October 7th 1938 is mentioned.

At page 315 of the german book is Annex B. [Annex B, Testimony of Bernard Bernstein, Chief of Investigation, to 'Kligore - Subcommittee' of US Senat, Washington D.C. December 11th, 1945] In Annex B is an interview excerpt of an I.G. Farben scientist. My summary what he said and Bernstein reported:

- German production of tetraethyl lead since begin of war was only possible by prewar shipment of complete factories (indeed plural: 'Erzeugungsstaetten' with full operational knowledge.

- The factories were build by Americans or under close American advice

- There was a very difficult development in USA with several deaths. Whole knowlegde was transfered for imidiate begin of production

- It was the first time Americans gave licence and secret operational knowledge to a foreign country.

- Was done on request of I.G. Farben to Standart Oil. US side had no obligation to such a deal.

- US War Department gave ok for deal after longer hesitation only

## CrossPoint v3.12d R ##

your quote 'Without tetraethyl lead, the octane number of the Luftwaffe's aviation gasoline would have been so low that a 2,000-hp fighter engine would have been able to deliver only 1,200-hp in the pinches - inadequate against Allied planes.'

big difference between won't run and won't run effectively.

Farther down in your post you quote material implying a power loss rather than destruction 'after some seconds'. (Damage due to knocking isn't *that* fast I believe.)

Alcohol is (and was) a well known substitute octane booster (there was in fact an active commerical competition between these two approaches in the 1920s). Some modification would have been required to use it, no doubt. But the fact that a shift to petrochemical/alcohol blends was easily within German capability might have made lead tetraethyl plants a much less tempting target.

Carey Sublette

If you have been studying the choices of targets for the allied heavy bombers in WWII you come across lists of targets that if destroyed contain claims that the Germans could not work around the subsequent shortages, with catastrophic effects.

Things like the electricity system and various chemicals are mentioned as the 'right' target. Rubber, nitrogen and so on.

Trouble is the Germans proved quite good at working around shortages and the catastrophic effects claims turned out to be overstated. Also claims of bombing causing permanent destruction were overstated.

There are ways to work around lower octane fuels and the Luftwaffe did not make much use of the real high octane fuels the allies did. As a general rule the Luftwaffe was behind the allies when it came to fuel octane ratings.

Why is this claim made when the following is included in the original post,

'Two prewar plants made tetraethyl lead in Germany: one at Gapel near Berlin, with a capacity of 100 tons per month, and one at Frose, near Magdeburg, with a capacity of 300 tons per month. Gapel was a peacetime plant built in 1936, whereas Frose was built secretly in 1938 to take care of wartime requirements.'

The third, big, plant was a secret but built and financed by the US?

Tetraethyl lead was an 'anti knock' agent, the Ethyl corporation had something like a monopoly in the US,

There are other ways to boost the octane rating of gasoline. One, as was stated by Carey, is alcohol, which the Germans used. Another is water (actually a water-alcohol blend). This was widely used in German aircraft towards the end of the war, some of which were extremely fast. So lead was hardly a critical component. In fact, the German bottleneck was not octane boosters, it was raw petroleum. Fuel of every kind was in desperately short supply by mid-1944.

If you know you aren't getting the proper fuel the mechanics can detune the engine to handle the lower octane fuel.

This was one of the key mistakes of the Allies in WW2... they thought they could find core industries, destroy them and end Germany's ability to make war...

They went after fuel... They went after ball bearings, thinking these were the critical industries that would do it.

Why didn't they go after the power plants instead?

I had in mind the performance loss of 40% hp the USSBS mentioned. If that is related to lower octane it means very big knocking. The octane number of the fuels tells what maximum compression in the engine in allowed. I found this data:

Compression Octane Number Brake Thermal Efficiency Ratio Requirement ( Full Throttle ) 5:1 72 - 6:1 81 25 % 7:1 87 28 % 8:1 92 30 % 9:1 96 32 % 10:1 100 33 % 11:1 104 34 % 12:1 108 35 %

Modern Otto engines run from 7 to 12 and modern untreated refinery fuels around 89 octane. If we face knocking today its due to an octane shift of only a few points and comes up on high speed only. Nevertheless I saw a pressure reading with twice peak pressure at knock compared to unknock. And that only a small time before normal ignition. If the octane number drops further the time before normal ignition raises and the peak pressure would raise much too.

In the situation the USSBS described 1940 none treated fuels had even lower octane then today. Imagine a high performance aircraft engine what needs 108 octane only gets 80. If it runs at all it could survive in iddle one minute perhaps with minor to moderate bearing damage. But speeded up it would not survive one minute.

Judging on the german efforts to get this stuff it looks like there was no substitute. Otherwise IG Farben would gladly offered it.

Ethyl alcohol has a high octane number and would indeed run with some modifications on the same high compression engines. But to keep the necessary octane number one would need 100% or at least a high percentage of alcohol in the fuel. Thats the way I read this:
http://www.radford.edu/~wkovarik/papers/kettering.html 'Ethyl alcohol was eliminated because of its lower BTU value, which meant that an airplane might have to take about one third again as much fuel to accomplish the same mission.'

Looks to me not just a range drop of 30% but an engine power drop of 30% too. Besides the grounding time they would need to modify the engines I still see the plants as the most tempting targets. A 30% loss in engine power (or 40% as the USSBS predicted) seems a lot in modern aviation. Could a FW-190 still reach a high altitude B-17 box in time to intercept? How would it reduce the bombload of a Ju-88? Cut to half?

## CrossPoint v3.12d R ##

So the #1 strategic target was actually in Romania, Ploesti. By mid-1944 it was indeed neutralized in the most effective way - from the ground.

Because their production of ethyl fluid was too limited? Quite more a reason to destroy this factories.

this is a citation from the USSBS

Here the USSBS writes only about the two tetraethyl lead plants Germany had at begin of war. Indeed the US build big Frose plant is mentioned as a secret project. I assume it was secret for the french, the british and the whole western public

Btw, I wrote nothing about the financing of the Frose plant. Do you know something about? At the end you wrote regarding financing:

what did you mean here?

It was not a target set of several sites in Germany but one or two single factories only. I see a allied capability to do it in 1941 at least. But the discussion of allied precission raid capabilities is a big and old one we should not open again.

This happend in mid 1944, as fuel went down and Luftwaffe already lost the battle over Germany. Without ethyl fluid this campaign would by much less costly for BC and USAAF.

Do you have any good reference for this claim? As americans were involved in building the plants...

## CrossPoint v3.12d R ##

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This seems to be a circular argument.

Germany did not have a shortage of lead tetraethyl, so why would the need a substitute?

This refers to pure ethyl alcohol as fuel.

Ethanol used as an octane booster is used in percentages of 10-30%. Its lower BTU value would result in a loss of fuel energy, but in the range of 3-10% when used as an additive. Unfavorable, but hardly catastrophic.

The '#1 Strategic Target' thesis suffers from fundamental weaknesses that plagued the 'critical bottleneck' targeting strategies of the war: * German industry had great adaptability - it had great scientific and technical resources and considerable unused industrial capacity until very late in the war. * The allies did not have perfect knowledge of the existence or location of all relevant plants for a particular 'bottleneck' material. * It proved extraordinarily difficult to actually take a plant out of production. 'Precision' bombing was a goal and results remained poor until very late in the war ; i.e. until the last year, when fuel was running out any way (some would argue it always remained poor). And Germany proved it could repair damaged plants very quickly.

too.

This is 'cooking the books'.

Octane boosting is used to *avoid* power loss, and the penalty of this can be a modest loss in total fuel energy (and thus range) if the solution reduces fuel energy density. You don't get power loss AND range loss.

The idea that the air force would ever have to be grounded reveals, I think, a conceptual flaw. This indicates you think that it would be possible to reduce leaded aicraft fuel suddenly and dramatically, rather than gradually and partially. The bombing effort could never reduce anything suddenly and dramatically. Plants went undamaged under attack, or were damaged, lost some capacity and were restored, were reattacked, and so on, stretching out over months or years. If partial loss in leaded aviation fuel occurred, engine modifications could be made to new production in the factory (remember - aircraft had to be continually be replaced) with no grounding.

Carey Sublette