Inaccurate performance data for BOB fighters in COD comparing to RL data

[CaptainDoggles]

Originally Posted by Seadog

Here's a source that states, unambiguously, that all of RAFFC converted to 100 octane:


A. R. Ogston, excerpt from History of Aircraft Lubricants (Society of Automotive Enginers, Inc. Warrendale, PA USA), p. 12.

Seems pretty straightforward but I wouldn't call this a primary source. Do they list their references?

[CaptainDoggles]

Originally Posted by Glider

Its very straightforward there is a limit to what I can and cannot prove and that is something that I have always been open about. I do not make assumptions, neither do I post part of the information available to me. So going back to the thread that I put a link in to earlier.

Posting 2
Shows the instruction from the Chief of the Air Staff for fighters and Blenheim units to be equipped with 100 octane. The ACAS has made the request but its safe to assume he wouldn't do this without the authority from the top. Its a clear request without any limits, it doesn't say certain, or limit the issue by Group or any other qualification.

Posting 3
Contains two papers the one that Kurfurst quotes saying Certain squadrons and the second paper that gives the actual status in both Bomber and Fighter commands.
Its worth noting that I didn't have to post the first paper, I knew at the time that the word 'certain' could be used to discredit the position and had I not posted it no one would have known, but for completeness I did include it.
If you look at my posting 12 it includes the line
I could see one line which I knew Kurfurst would almost certainly leap on and could have left it out, but that would have broken the train so I kept it in.
I can only assume that he didn't dare use that word then but has now decided to do so. Anyway back to your question.

Posting 4
Here you can see that as a cost saving measure the Authorities wanted to keep one tank of 87 octane for visiting aircraft passing through. Bomber Command were against this and permission was given in some cases for all the fuel to be 100 Octane.
Note the terminology, the 87 Octane wasn't for non operational flights, but for aircraft passing through.

Posting 5
is an update report

Posting 6
Is the paper confirming the completion of the switch from 87 to 100 octane. I do make the observation that
What is interesting is what isn't in the file and its a big file. At no stage is any concern expressed about any shortage of 100 Octane Fuel the level of stocks or any lack of supply. There was never any mention of capping distribution or shipping stocks from one station to another or sector

Posting 12
This is interesting for a different reason. It refers to the experimental production of 100 Octane fuel at a UK Refinery which produced 35,000 tons over four months, at a time when average useage was 10,000 tons a month. In other words had there been a shortage then the UK could easily have been self sufficient. The experiment did take place but due to cost grounds it was switched back to normal production when complete

I was asked if I had a list of when each station was equipped with 100 octane but there wasn't a schedule in the NA files.

It should also be noted that Kurfursts position was that only 18 fighter squadrons were equipped with 100 Octane which is one reason why I was asking him to state what number of aircraft or squadrons was he talking about in this forum being equipped with the better fuel.
It should be noted that we identified well over 30 squadrons which reported the use of the extra boost and additional stations which had 100 octane over and above the ones listed in the records. 100 octane was used in France and Norway so it was widely used and a standard issue

Posting 63
Kurfurst was getting a little desperate at this stage and I was totally open about my position saying
I think one thing has to be made clear. Can I give a 100% Cast Iron, Gold Plated guarantee that every station in fighter command had 100 Octane fuel. No I cannot, as that would involve checking vast amounts of data and I have a life to lead, so in short there could be one station in the back end of nowhere which didn't get the fuel. As Kurfurst rightly pointed out I used the phrase , "sources links that exist and support the view that Fighter Command was effectively fully converted to 100 Octane by May 1940. Note the word effectively.
That said I do believe and there is no evidence in my mind to contridict the view that all stations did have the 100 Octane Fuel.

This remains my position. There is no evidence anywhere that Fighter Command was anything but 100% fully equipped with 100 Octane. Hundreds of books have been written about the battle, probably more than on any other conflict and scores or personal memories and no one ever has mentioned this theory. No one has mentioned the obvious logistical or practical problems that having mixed fuel would mean.

We have a document trail from the instruction from the Chief of the Air Staff asking for fighters to be equipped with 100 Octane and the other papers that follow the implementation until completion. Why did someone type in certain on one paper I have no idea and am not making any assumptions.

We have other papers that were issued by Dowling about the dangers of using the extra boost and not telling the ground crews, papers that were issued to all of fighter command not just some units or stations.

Against this we have a paper that is supposed to exist in Australia which they have never heard of, which Kurfurst has never seen and had never asked for and finally if it does exist, is riddled with errors.

I am very aware that I have made serious accusations about Kurfurst but I have supported my comments and before anyone deletes these postings I suggest you check them out.

If you incorporate his theories into any code then you do stand a chance of being made to look very foolish..

I'm in the process of reading this thread and I can tell you that almost everyone involved "looks foolish", yourself included.

Stop editorializing what you think Kurfurst is doing (Kurfurst is desperate, etc) it only serves to make you look petty, petulant, and juvenile. Indeed from reading your postings at ww2aircraft.net that is the conclusion to which I have come about your character.

In any case, I'm still reading the two threads and have yet to come across any definitive proof that RAF aircraft were 100% equipped with 100 octane at all times. I'm willing to be persuaded but that has not yet occurred.

[CaptainDoggles]

Kurfurst,

Could you kindly post a link to this article written by the australian author directly? I have been waiting almost 2 weeks for my account at allaboutwarfare.com to be activated but it hasn't happened yet.

[Danelov]

Data of the Fiat G.50 Freccia.

Weight(MTOW): 2402 kg
Empty weight: 1963 kg
Max speed: 472 kph/5000m
Cruise speed: 415 kph
Range: 670km
Ceiling: 10,700m
Climb rate: 6000m in 7'30'' ,5000m in 6'3''
Weapons: 2x Breda SAFAT with 150 rounds p/gun
Gunsight Type S.Giorgio at riflesione
Ammo: Counter included in panel
Fire system: Warning light, extintor at biossido di carbonio.
Radio: ARC 1
Fuel: 260 l(provision for 52 l of aux fuel in a fuselage tank)
Power: Engine Fiat A.74 RC, radial, 14 cylinders
740 HP in take off.
840 HP with 2400rpm at 4000m
879 HP with "+100"(WEP)
Propeller: Hamilton Standard 3D-41-1, constant speed, passo variabile
Misc: In panel/cockpit: Carburator heat switch, gear indicators, fire warning light, compressed air indicators, ammo counter, engine instruments, compass, cowling flaps selector, Flaps lever, parking brake lever.
Other: The G.50 turn well to the right but less satisfactory to the left . Stall with 125 to 130 kph. Exit of stall with turn to the right.

Dates from: "Fiat G.50 Le Macchine e la Storia, Stem Mucchi, Modena-Italia"

[Seadog]

Originally Posted by CaptainDoggles

Seems pretty straightforward but I wouldn't call this a primary source. Do they list their references?

That's all I have for now.

[Bobb4]

While not definative it provides a date when the British public may have become aware of 100 octane

[Bobb4]

And here is a site that discusses in length the benefits of the 109/Spit including pilot anidotes and references the introduction of 100 Hi-Octane fuel
http://www.spitfireperformance.com/spit1vrs109e.html

And for those to lazy to read...

The Merlin III engine data is from Rolls-Royce. 24 The DB 601A engine data is taken from curves found in the DB 601 A u. B Motoren-Handbuch of May 1942. 25 Trials were successfully carried out in October 1939 to increase the power of the Spitfire's Merlin II and III engines by raising the manifold pressure to +12 lbs./sq.in. 26 Air Ministry A.P.1590B/J.2-W. dated 20 March 1940 gives official notice that "The emergency use of higher boost pressures up to +12 lb./sq. in. is now permitted for short periods by operation of the modified boost control cut-out". 27 Also during February and March 1940 Spitfire and Hurricane Squadrons were converting their aircraft over to 100 octane fuel, which made possible an increase in engine power by raising the boost to +12 lb/sq.in.. 28a 28b 28c 28d 28e 28f 28g 28h 28i 28j 28k 28l 28m 28n 28o 28p 28q 28r 28s 28t Combat reports show that +12 lb boost was used by the Spitfire (and Hurricane) squadrons during their first combats with the Me 109 E in May 1940 while covering the Dunkirk evacuation. 29 30 Hurricane Squadrons based in France during May of 1940 were also employing +12 lbs/sq.in. boost in combat. 31 31b

The first Spitfire into service was delivered to No. 19 Squadron at Duxford on 4 August 1938. The use of 100 octane fuel was approved for Spitfire Squadrons by 24 September 1938. 32 Fighter Command noted on 6 December 1938 that Duxford, Debden, Northholt and Digby had received 100 octane fuel. 32b As of December 1938 Nos. 19 and 66 were based at Duxford and were the only RAF units then equipped with Spitfires. The Air Ministry noted in a memo dated 12 December 1939 that "100 octane fuel is approved for use in Hurricane, Spitfire and Defiant aircraft, and state that issue will be made as soon as the fuel is available in bulk at the distribution depots serving the Fighter Stations concerned." 32c Gavin Bailey concluded that "The actual authorisation to change over to 100-octane came at the end of February 1940 and was made on the basis of the existing reserve and the estimated continuing rate of importation in the rest of the year." 33 As of 31 March 1940 220,000 tons of 100 octane fuel was held in stock. 34 The Co-ordination of Oil Policy Committee noted in the conclusions of their 18 May 1940 meeting with regard to the "Supply of 100 Octane fuel to Blenheim and Fighter Squadrons" that Spitfire and Hurricane units "had now been stocked with the necessary 100 octane fuel". 35 The Committee recorded that actual consumption of 100 octane for the 2nd Quarter 1940 was 18,100 tons. 36 Jeffrey Quill recalled:

It was only shortly before the Battle of Britain that we changed over to 100 octane. It had the effect of increasing the combat rating of the Merlin from 3000 rpm at 6 1/2 lb boost (Merlin III) or 9 lb boost (Merlin XII) to 3,000 rpm at 12 lb boost. This, of course, had a significant effect upon the rate of climb, particularly as the constant speed propellers (also introduced just before the battle) ensured that 3,000 rpm was obtainable from the ground upwards whereas previously it was restricted by the two-pitch propellers. It also had an effect upon the maximum speed but this was not so significant as the effect upon rate of climb. 37

Wood and Dempster wrote in their book "The Narrow Margin":

As it turned out, aviation spirit was to prove no worry for the R.A.F. By July 11th, 1940, the day after the Battle of Britain opened, stocks of 100 octane petrol used in the Merlin engine stood at 343,000 tons. On October 10th, twenty-one days before the battle closed, and after 22,000 tons had been issued, stocks had risen to 424,000 tons. With other grades of aviation spirit total stock available on October 10th, 1940, was 666,000 tons. Oil reserves were 34,000 tons. 38

Wood & Dempster’s figures for stocks of 100 octane are in agreement with those of the War Cabinet, however, their figure of 22,000 tons issued falls short of the Air Ministry’s figures as shown below. By 7 August 1940 "authority has been obtained for the use of 100 octane fuel in all operational aircraft and that instructions to that effect are being issued to Commands", i.e. all operational aircraft in Bomber, Coastal, Training and Fighter Commands. 39 On October 29, just before the end of the Battle of Britain, 423,400 tons of 100 octane fuel was in stock in the UK. 40a The War Cabinet recorded that 100 octane stocks stood at 202,000 tons on 31 December 1939 and that 100 octane stocks had risen to 499,000 tons one year later on 31 December 1940. 40b The Air Ministry recorded that 58,000 tons of 100 octane were issued during the Battle of Britain. 40c The War Cabinet recorded that 100 octane consumption within the UK for the whole of 1940 amounted to 130,000 tons, an average of 2,500 tons per week. 40d Consumption of 100 octane during the Battle of Britain averaged 10,000 tons per month for the months of July and August rising to 14,000 tons in September followed by 17,000 tons during October. Total consumption of 100 octane fuel during the Battle of Britain therefore was on the order of 50,000 tons. 40e V. A. Kalichevsky, author of the 1943 book The Amazing Petroleum Industry wrote:

It is an established fact that a difference of only 13 points in octane number made possible the defeat of the Luftwaffe by the R.A.F. in the Fall of 1940. This difference, slight as it seems, is sufficient to give a plane the vital "edge" in altitude, rate of climb and maneuverability that spells the difference between defeat and victory. 40f

The Spitfire I Pilot's Notes lays out the use of +12 boost as follows:41



An August 1, 1940 memo from Air Chief Marshall Dowding to all Fighter Groups shows that the pilots often exceeded these limits.

The use of the automatic boost cut out control enables the pilot to get an emergency boost of + 12 lbs. per sq.in. from the engine for 5 minutes when circumstances demand it. Some pilots "pull the plug" with little excuse on every occasion. 42

[Glider]

Originally Posted by CaptainDoggles

Stop editorializing what you think Kurfurst is doing (Kurfurst is desperate, etc) it only serves to make you look petty, petulant, and juvenile. Indeed from reading your postings at ww2aircraft.net that is the conclusion to which I have come about your character.

In any case, I'm still reading the two threads and have yet to come across any definitive proof that RAF aircraft were 100% equipped with 100 octane at all times. I'm willing to be persuaded but that has not yet occurred.

At least I am a petty, petulant and juvenile person who post sources, links and original documentation.
Being serious for a moment, if you have any questions or explanations don't hesitate to ask either on the forum or by PM. That offer is obviously open to anyone.

[Bobb4]

Maybe i missed something but why the debate on 100 octane at all, is there a quotable source that says it was not available?
Again all the sources I have found indicate it was, and ironically even during the Battle for France 12 lb boost was used an indication 100 Octane was available then?

[Glider]

Originally Posted by Bobb4

Maybe i missed something but why the debate on 100 octane at all, is there a quotable source that says it was not available?
Again all the sources I have found indicate it was, and ironically even during the Battle for France 12 lb boost was used an indication 100 Octane was available then?

There isn't one that I or anyone else has found.