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Use of 100 Octane Fuel in the RAF during BOB

Technical Discuss Use of 100 Octane Fuel in the RAF during BOB in the World War II - Aviation forums; Okay, another dumb question, what were the stocks of 87 Octane at the same time, and what was the comparative ...

  1. #46
    Senior Member parsifal's Avatar
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    Okay, another dumb question, what were the stocks of 87 Octane at the same time, and what was the comparative consumption in that same time period. If it is markedly greater than the 100 Octane consumption, wouldnt that indicate a continued dominance of the use of that fuel grade in the squadrons????

    Fr President Clemenceau’s speech to the AIF 7th July 1918: “ we expected a great deal of (Australians)… We knew that you would fight a real fight, but we did not know that from the beginning you would astonish the whole continent. I shall go back and say to my countrymen “I have seen the Australians, I have looked in their faces …I know that they will fight alongside of us again until the cause for which we are all fighting is safe for us and for our children”.



  2. #47
    Senior Member Juha's Avatar
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    hello Parsifal
    You must remember that Fighter Command was only one part of RAF, there were also Bomber, Coastal and Training Commands plus maybe also Maintenance Command used some aviation fuel. And IMHO probably at least the Blenheims of 2 Group/BC probably used 100 oct because after converting from Mk Is to Mk IVs in 1939/early 40 only with it they could take full benefit out of the Mercury XV, ie the use of +9 lb boost, and Blenheims desperately needed all extra mphs they could get and many of the 2 Group missions were flown at low level.

    Juha

  3. #48
    Banned Kurfürst's Avatar
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    I believe the consumption of 'other grades' coloumn is practically equiavalent of 87 octane consumption, as it is doubtful that lower octane aviation fuel was used. According to the table, that would be, for example, 14 000 tons of 100 octane avgas against 23 000 tons of 87 octane avgas consumed in September 1940, ie. the majority of consumption, about 2/3s, was 87 octane. According to the table, the sitauation was the same in the month before, with 87 octane being the major fuel type consumed.

    However, the tables produced by Williams doesn't seem to match the figures given by Wood and Dampster (I suspect that they are working from the very same AIR document, ie. take note that the July 11 - 11 October 10 1940 period is equivalent of the Q3 1940 and other similiarities, however the part of the document which deals with the actual Q3 consumption is not revealed to public to unknown reasons) as 22 000 ton being issued against about 34 000 tons claimed to have consumed.

    I would say to say that units could in some mysterious way, consume more fuel than they were issued, is very interesting notion, but not a likely possibilty in our physical reality.

    Another oddity about the tables produced by Williams is the disparity between the 'Table II - Consumption' and the first document 'Annexure A'.

    While the former shows that no 100 octane fuel was consumed at all until June 1940, and all consumption constituted of 'other grades' (~87 octane), the 'Annexure A' document show the 'actual consumption in the second quarter' of 1940 (ie. April-June) as 18,100 tons. Curiously enough, there is no reference given for this former table of consumption. Allegedly it is found in the National Archieves, but with the reference withheld, it is ensured it cannot be checked. Given the inconsistencies and the circumstances, there is something fishy here.

    Add to that, as was referenced in the 7th meeting in May, the 'Oil Committe made its position clear' to Fighter Command in the Sixth meeting, which sound very much like the material in the Australian Archieves about the suspension of 100 octane conversions due to inadequate reserves in May. I find it noteworthy, that neither Glider nor Williams is willing to reveal the contents of this meeting and the preceding meetings.

    In any case, none of the documents so far show any reference to the number of Squadrons that used 100 octane fuel in 1940, expect for the March 1939 which reveals that 16 + 2 were intended, conversion starting in the end of 1939. The 7th meeting also speaks of 'Squadrons concerned', indicating the new fuel was allocated to select Squadrons only.

    This March 1939 decision may have been overridden later. However, if this would be the case and the number of Squadrons were to be increased in a later decision, doubtlessly it would be waved around all over the place.

    But there's no such waving of evidence, in fact, whenever the question arises what position was made clear by the Oil Committee before the 7th meeting in May 1940, the silence is deafening.

    BTW the question of German avgas situation was raised earlier in this thread by Glider, perhaps the following paper is of value to that discussion. Appearantly, German reserve stocks of avgas were between 600-680 000 tons, the actual consumption being 80-100 000 tons per month.

    Last edited by Kurfürst; 02-02-2009 at 12:25 PM.

  4. #49
    Banned Kurfürst's Avatar
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    Quote Originally Posted by Glider View Post
    By the way the 800,000 tons reserve wasn't just for fighter command and was never met but I think that even would agree that it didn't stop us using it.
    Certainly.

    But, at the present state of evidence, it seems that 16 Fighter Squadrons and 2 twin (Blenheim) engined bomber Squadrons were the only ones eligible to receive the new fuel type.

    What position was made clear by the Oil Committee to Fighter Command in May, Glider?

    Would it be an accurate summary that :...actions were immediately undertaken by the British War Cabinet in May to resolve the looming crisis. Firstly 87 octane fuel was deemed the primary fuel source to be used until further supplies could be discovered and delivered in sufficient quantities to allow the Merlin conversions to again take place. Those existing fighters already so converted (approximately 125) would continue to use what supplies of 100 octane were available, but all other fighters that had not been modified to continue with the use of 87 octane (of which there was more than adequate supply).

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    Read my first two posts Kurfurst. The timeline and meanings are laid out and defined. Everything in those posts is supported by official documents and your statements are no more than a conspiracy theory.

    I don't know what the actual words or minutes of the meeting of 7 May are, just the paper that you have seen.

    The difference is I am saying that I don't know, but I also believe that you don't know either, but you are working on an assumption that you do know. If you did have the paper and it supported your theory, then you would have posted it.

    Your whole argument is based on an assumption of what was said in that meeting and of course the Australian paper and I am becoming more convinced that you don't have access to the Australian Paper either and probably never have had a copy.

    We agree that it is the responsibility of the person making the statement to support that statement with evidence. So supply that evidence.
    Last edited by Glider; 02-07-2009 at 08:33 AM.

  6. #51
    Senior Member Juha's Avatar
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    Kurfürst
    Quote:” While the former shows that no 100 octane fuel was consumed at all until June 1940, and all consumption constituted of 'other grades' (~87 octane), the 'Annexure A' document show the 'actual consumption in the second quarter' of 1940 (ie. April-June) as 18,100 tons.”

    Are You desperate or incapable to read even a simple table? The Consumption table clearly shows that before June 40 Aviation fuel consumption is given as total, without dividing it between 100 oct and other grades, that’s why the first 3 consumption figures are given in middle, between the columns “100 Octane” and “Other Grades”.
    Now can you give a source, book or document which says that only ¼ of FC fighters used 100 oct fuel during the BoB, I mean other than “I think” or “an Australian”. In Hurricane vs Bf 110 thread others gave at least some 6 books/articles that says that FC converted to 100 oct before the BoB, can you give even a couple that say that ¾ of FC fighters used 87oct fuel during the BoB? “The generally accepted fact” is that FC fighters used 100 oct during the BoB, if you think otherwise, please produce some generally acceptable proof to back up your position.

    Juha
    Last edited by Juha; 02-02-2009 at 03:44 PM.

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    Senior Member pbfoot's Avatar
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    Quote Originally Posted by pbfoot View Post
    an article by Bill Gunston
    "One vital factor often overlooked in accounts of the BoB was the power increase RAF aircraft obtained from using 100 octane fuel. To get an octane rating of 100 required a very complicated process which done on a commercial scale required a large and exspensive refinery plant. Though Dr. SF Birch of Anglo -Iranian's laboratory at Sunbury on Thames was the pioneer of this alkylation process it was the US Army Air Corp that pioneered 100 octane aviation fuel . Probably nothing would have happened in Britain had it not been for a great engine man Air Commodore Rod Banks who Jan 1937 urged that RAF engines should be able to use 100 octane " even if the supply of such fuel were limited, because the use of high -duty equipment might prove decisive in the air in the early stages of a war"
    Accordingly , two British emgines one of them the Merlin ,were tested and developed to run on 100 octane which was available only from abroad . Eventually an outstanding fuel called BAM 100 ( British Air Ministry 100) was developed , and the first cargo was shipped to Britain from the ESSO refinery in Aruba in June 1939. The Air Ministry stockpile the valuable fuel which was dyed a distinctive green the fact remained unknown to german intelligence. This stockpiling went on throughout the war , but in may 1940 when the chips were down and everything counted the RAF began to use the special fuel in the Merlins of Fighter Command"
    this piece that I typed word for word answers the date for start of use IMHO

  8. #53
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    i noted before of BoB they estimed consume of 100 octane for julliet/december in ~94K tons of 100 octane spirit, the actually consume for june/december it's only ~72K tons, it's logic that consume up the estime with BoB but not, maybe there are some change in the units planned of use it, late in october they estimated a consume of 31K fot november/december and actually consume was 31K

  9. #54
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    Kurfurst,

    I'm afraid a lengthy response on the responsible handling of historical evidence appears to be required. Quoting, at second-hand, a secondary source as a reference which cannot be traced or supported by any primary source evidence is not sufficient to overcome the wealth of primary source evidence that I have cited in my article, or that Mike Williams and Glider have posted in this forum. If you want that reference to be taken seriously, then please cite an available primary source reference to the alleged War Cabinet decision that the roll-out of 100-octane needed to be stopped due to supply shortages in May 1940. Absent such evidence, the Australian paper quoted is clearly in error, You may prefer to believe it for your own reasons, but it is not a historically-credible source.

    Re: the references I posted: they were cited accurately to enable you (and any other reader) to view them for yourselves; this is standard practice in any historical thesis or article subject to publication. If you are unable to accept my handling of the references concerned, and are unwilling to wait for Glider or Mike Williams to go to Kew, take digital photos and post them on this forum, then I suggest you use the facility available on the PRO website to order photocopies of the relevant documents yourself.

    My thesis, if this requires further clarification after my original posting on this forum, is that 100-octane fuel was supplied from a diversity of sources within and outside the US (in contrast to the received wisdom), but also was in widespread use during the Battle of Britain, as a mass of incontravertable primary source evidence demonstrates (in conformity with the received wisdom). Yes, you have quoted one decision mentioned in my article about the planned use of 100-octane fuel in selected squadrons in 1939. However you then ignore the text and references which then indicate that this decision was overtaken by others. Highlighting that first decision without exploring the subsequent changes to it is either mistaken or dishonest. If you cite my work again, I would ask you to make it clear that I have explictly and publically disagreed with your revisionist appreciaton of the use of 100-octane in Fighter Command during the Battle of Britain.

    >As for the 10th August meeting, it does note that they intended to use 100 octane fuel for all operational aircraft of all Commands; from the actual rate of fuel consumption by type of fuel, it is also clear that this remained a plan and did not materialize.

    I suggest you substantiate this assertion with some convincing original source material. Then you can start instructing me on the requirements for evaluating historical evidence to support a hypothesis. Now for the conclusions from this Australian paper which you reproduce:

    The subsequent escalation in air activity and demands placed upon Fighter Command over the next two months put great strain on both the 100 octane fuel stockpiles and aircraft modified to use the fuel. Against the backdrop of total war the RAF found that it's reserves of 100 octane fuel was well below the level considered necessary for widespread use, for any sustained length of time.

    And yet the decisions for Fighter Command and then all operational units to use the fuel are recorded in May and August 1940, as are the levels of reserve involved, and the levels of anticipated importation which made it clear that the war reserve figure would be reached in 1941 despite beginning the operational use of the fuel. Please don't bother to quote this text again without some original source material to support the assertions in it, as it is clearly and convincingly contradicted by the original sources from the relevant bodies in the Air Ministry and Committe of Imperial Defence which have already been cited.

    What concerns me is the selective use of evidence in this thread. To echo Glider's comments to another participant, this is not a debate or discussion, merely a futile exercise in which some posters go to substantive efforts to produce primary source material to refute a belief held by another poster which remains impervious to such evidence. On the basis of the evidence posted so far, there is no illusiary 'middle ground' here between two competing but legitimate opininions. Your view is mistaken. If you disagree with that, then start dealing with the evidence that contradicts your opinion and start assembling some credible evidence which supports that opinion.

  10. #55
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    Mike, thank you for the kind words, but even more for the evidence on the operational use of the fuel you have posted here (thanks also to Glider in that respect). I must admit, my intentions in my article were simply to challenge the perceived impact of 100-octane in the BoB and also the attribution of national origin to the fuel used, rather than demonstrate that it was used at all, which still appears to a rather exceptional interpretation. I did check some station ORB's in 11 Group for evidence of 100-octane supplies, which was patchy, e.g. Hornchurch clearly had it, as indicated from other sources (including rail deliveries of SO (NY) contracts in 1937-9, but it wasn't mentioned in the April-May 1940 ORB (note for Kurfurst before he jumps on it - other stations did record it). The 611 Sqn ORB is particularly useful in that respect, so thanks for that.

  11. #56
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    Interesting discussion everyone.
    Can anyone supply the different max speeds for the Hurricane & Spitfire.
    1939/40 - standard propeller
    1940 - new constant speed propeller
    1940 - with also 100 octane fuel.

    However, to add to the on going discussion, I'll add a couple of quotes:
    From Wilfred Freeman's biography p.94/95 -
    "The RAF had been using 87 octane for some years, but a change to the higher grade would permit safe use of higher supercharger pressures (boost), and extract the maximum value from the new engines and variable pitch propellers. the production capacity of German refineries was estimated to be roughly 970,000tpa of 100 octane by 1938, and it was clear that to remain competitive, the RAF would have to start using 100 octane fuel for operational aircraft as soon as possible.
    Free world production of 100 octane fuel at this point was roughly 1,000,000 tpa, of which Britain contributed only 125,000, and Freeman urged the Government to establish capacity to meet potential deficiencies as a matter of the utmost importance, recommending the erection of three huge new hydrogenation plants one in britain fro 200,000 and two in Trinidad, one for 200,000 and one for 300,000 tpaat a total cost of £9m."
    After Treasury amendments on 7 March 1939 authority was given to construct two new refineries with a capacity of 720,000 tpa, with another one being sanctioned after the outbreak of war.
    And -The Battle of Britain by Richards & Hough P.35
    By March '40 Fighter Command was beginning to convert its Merlin-engined Hurricanes and Spitfires to accept 100 octane fuel. Hurricanes in France during the brief French campaign were still running on blue 87 octane, and it came as a considerable shock to Me 109 pilots in particular who witnessed the startling improvement in the performance of both the Hurricane and Spitfire from July 1940 onwards. Adolf Galland confessed that he was puzzled by the improvement of the enemy's performance until late in August when fuel from a crashed RAF fighter was analysed. The Luftwaffe operated thoughout of 87 octane fuel.

  12. #57
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    The following gives some good details on the Hurricane
    Hurricane Mk I Performance

  13. #58
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    Merlin, the sources quoted from the PRO AVIA 10 series come from Freeman's papers at the PRO, and date from his time as Air Member for Development and Production on the Air Council; this is one of the main sources for Anthony Furse's biography which you refer to.

    I referred to the relevant performance improvements involved in using 100-octane fuel and the constant-speed variable-pitch propeller with the Spitfire IA and IIA in my article. These were taken from Alfred Price's The Spitfire Story but also confirmed by checking the relevant A&AEE reports in the PRO AVIA 18/682. These are complicated by the marginal dissimilarity of the aircraft used for test purposes, but their specification, weight and finish were close enough for representative purposes.

    Basically, a Spitfire I on 87-octane and a two-position, fixed pitch propeller could achieve 366 mph at 20,000 ft, and take 11 mins 24 seconds to climb to that height.

    A similar aircraft on 87-octane and a constant-speed, variable-pitch propeller could achieve 353 mph at 20,000 ft, and take 7 mins 42 seconds to climb to that height.

    A Spitfire IIA on 100-octane and CS/VP prop could do 351 mph at that height, and take 7 mins exactly to climb to that height.

    I used these figures to indicate that the adoption of the CS/VP prop improved Spitfire performance by 33%, with the use of 100-octane fuel improving it by a further 7%.

    At the risk of self-promotion, I'll refer you to my article for a fuller treatment of the various secondary sources concerning the use of 100-octane fuel in the BoB, including Hough & Richards. To summarise, the original sources mentioned in this thread (and with digital photos kindly provided by other participants) trump those secondary sources.

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    Senior Member parsifal's Avatar
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    It seems a pretty convincing argument to me that 100 octane was in widespread usage during the battle by the RAF. I ahve read that this conferred substantial performance improvements to the RAF fighters engaged.

    However, the German supporters of this forum have been quick to point out that the Germans also developed and used higher Octane fuels (it should be noted that the german rating system is not directly comaparable to the allied octane rating system). My basic question is this.....did the Germans actually introduce higher octaned rating fuels, and if so, when did this begin to occur?
    Fr President Clemenceau’s speech to the AIF 7th July 1918: “ we expected a great deal of (Australians)… We knew that you would fight a real fight, but we did not know that from the beginning you would astonish the whole continent. I shall go back and say to my countrymen “I have seen the Australians, I have looked in their faces …I know that they will fight alongside of us again until the cause for which we are all fighting is safe for us and for our children”.



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    Senior Member Juha's Avatar
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    late 40 LW got some DB 601N engines which used C3 fuel, 96 oct. But those engines were scare and they argued at highest levels of LW for ex how to divide 240 of them between 109s and 110s and how many to reserve. One can see which a/c got the engine by N sign, for ex Bf 109E-4/N. Early 109Fs had also DB 601N engines but G series was powered by DB 605A engine up to say mid/late 44 and it used again B4 fuel which was 87 oct. Those octane numbers are bit misleading IIRC late C3 was close to British 100/150 oct fuel in performance.

    So LW got higher octane fuel in limited operational use in late 40 and it was the fuel used in 109F-1s and F-2s, (IIRC DB601E switched back to B4 fuel (engine of 109F-3s and -4s)) and all 109Es and 110s which had sign /N. But then LW mostly switched back to B4 but IIRC 190As used C3. And from say mid 44 onwards the use of C3 increased again.

    Juha
    Last edited by Juha; 02-08-2009 at 07:57 AM.

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