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

[Kurfürst]

Originally Posted by Glider

If you believe that the RAF only used 16 squadrons of fighters with 100 Octane until Sept 1940, then you need to explain why we have over 30 squadrons mentioning it in combat reports. I think that counts as counter evidence

I suggest you cease putting words into my mouth; nowhere I had suggested that the use of 100 octane was limited to 16 Squadrons, this may or may not have been revised, but given that there is an absolute lack of evidence that happening, any such thesis remains in the realm of wishful thinking. However the trail of evidence is clear, in 1939 the RAF clearly intended to issue the fuel to select Squadrons. In May 1940 the archive papers have noted that this policy of limited use was followed, as the papers still note that only select units/stations are supplied.

You have not produced anything that would suggest this policy was revised. Fuel issue/consumption records show that the 87 octane remained the main type issued and consumed.

So instead of dancing on the words and expecting others to disprove the unsupported thesis you are speculating about, how about producing a single paper saying that all Squadrons are/are to be supplied, hmm? So far your record with that is dismay failure.

Moreover, as you said you have combat reports from pilots from about 30 Squadrons (rotating between Stations that selected to be supplied with 100 octane as others have also correctly pointed out, so alone it gives very little idea of how many units were using the fuel at one time) so one just wonders on really what basis you are claiming that not 30 but 60+ Squadrons were all using 100 octane fuel, when you have only evidence for half of them. After years of rather barren research.

[41Sqn_Banks]

I found this document http://www.wwiiaircraftperformance.o...tane-issue.pdf rather interesting.

[Kurfürst]

Originally Posted by 41Sqn_Banks

I found this document http://www.wwiiaircraftperformance.o...tane-issue.pdf rather interesting.

Indeed that fits into the story nicely.

"serving the fighter stations concerned"

"certain units of Bomber Command"

".. 100 octane fuel will come into use in all the approved stations"

"bulk storage could be made available at the relevant stations"

Quite clear isn't it. Just don't make the mistake that Glider is not aware of all that, he is, for a long time, he just ignores the evidence.

[41Sqn_Banks]

Originally Posted by Kurfürst

Indeed that fits into the story nicely.

"serving the fighter stations concerned"

"certain units of Bomber Command"

".. 100 octane fuel will come into use in all the approved stations"

"bulk storage could be made available at the relevant stations"

Quite clear isn't it. Just don't make the mistake that Glider is not aware of all that, he is, for a long time, he just ignores the evidence.

I read it a bit different. "Issue of this fuel to certain units in the Bomber Command will, however, take precedence over the units equipped with the above mentioned types of aeroplanes." There is a clear constraint on "certain" units in Bomber Command but no constraint on units with Hurricane, Spitfire and Defiant.

... it is not possible to state a day on which 100 octane fuel will come into use in all the approved stations."

Pretty much sums it up. We won't find a exact date, the change was made a soon as possible.

The "approved stations" are given in the referenced letter No. F.C. 15447/76/E.Q.2:
http://www.wwiiaircraftperformance.o...0oct-issue.jpg
http://www.wwiiaircraftperformance.o...0oct-issue.jpg

It was also shown here:
http://forum.1cpublishing.eu/showpos...&postcount=121
http://forum.1cpublishing.eu/showpos...&postcount=125
http://forum.1cpublishing.eu/showpos...&postcount=133
http://forum.1cpublishing.eu/showpos...&postcount=135

that the "certain units" of Bomber Command had received 100 octane fuel until May 1940. And then the Fighter stations started to receive 100 octane fuel, which pretty much agrees with the reported use of 100 octane fuel in several fighter squadrons starting from May 1940.

[NZtyphoon]

"These are, or will be operational Stations although they have no Hurricanes or Spitfires at the moment. In the near future these stations will have Merlin engine aircraft that will require 100 octane fuel." 9 December 1939

Not might require, not maybe require but will require 100 octane fuel. Clear recognition that as early as December 1939 Merlin engine aircraft such as the Hurricane and Spitfire required 100 octane fuel, and that bases operating Merlin powered aircraft needed stocks of the fuel.

[Crumpp]

If we assume that 16 squadrons operated on 100 octane at one time, by summing up the Spitfire, Hurricane and Defiant* squadrons in No. 11 Group we get:

Good work. My original post also noted that in September, 16 squadrons was a significant portion of Fighter Commands combat power.

The points to think about:

It was not until sometime in September the RAF had 16 fighter squadrons using 100 Octane. That could be the 1st of September or the 30th of September that 16 squadrons were operational. We don't know the exact date. I point this out because during the 100/150 grade debacle, knowing the exact dates revealed the fuel was used for several weeks before being withdrawn in the 2nd TAF. During that time, many squadrons converted back to 100/130 grade on their own because of the unreliability of the engine when using 100/150 grade. As a pilot myself, I have an aversion to flying with anything that will stop that propeller from turning, too. I like it when it works and don't like dying.

Second point is the logistical planning of the RAF in many ways was much better than the Luftwaffe. I would be willing to bet the RAF did not wait and suddenly stand up those 16 squadrons at once. Instead, at the completion of operational trials, the units were stood up on 100 octane as soon as the field built up the required reserve, the aircraft converted, and the logistical support in place to maintain combat operations.

This would make for a gradient curve and by sometime in September a full 16 squadrons were using the fuel. A word of caution, this is just my opinion and stated to participate or add fuel to any "make my gameshape better" butchering of history.

Unfortunately, we don't have the facts to fill in the gaps in our knowledge on that part so the very presence and actual slope is just more guesswork.

Given time, the facts will be revealed. Five years ago, I know very little about the development details or extent of operational use of either GM-1 or Alkohol-Einspritzung on the FW-190. We just knew we wanted our aircraft to be as authentic a restoration as possible. After several years of ploughing archives the gaps in our knowledge have narrowed considerably and the picture is much clearer.

The same will happen with the introduction of 100 Octane. I highly doubt it will be solved here and now. The answer is probably collecting dust in the files of an archive somewhere.

[Kurfürst]

[QUOTE=41Sqn_Banks;399463]I read it a bit different. "Issue of this fuel to certain units in the Bomber Command will, however, take precedence over the units equipped with the above mentioned types of aeroplanes." There is a clear constraint on "certain" units in Bomber Command but no constraint on units with Hurricane, Spitfire and Defiant.

Only if you simply forget about the preceeding sentence - ""serving the fighter stations concerned". Its a quite clear constraint, repeated again in the April - May docs, posted previously.

Originally Posted by 41Sqn_Banks

The "approved stations" are given in the referenced letter No. F.C. 15447/76/E.Q.2:
http://www.wwiiaircraftperformance.o...0oct-issue.jpg
http://www.wwiiaircraftperformance.o...0oct-issue.jpg

The paper reads to me as a request, not an approval.

It was also shown here:
http://forum.1cpublishing.eu/showpos...&postcount=121
http://forum.1cpublishing.eu/showpos...&postcount=125
http://forum.1cpublishing.eu/showpos...&postcount=133
http://forum.1cpublishing.eu/showpos...&postcount=135

that the "certain units" of Bomber Command had received 100 octane fuel until May 1940. And then the Fighter stations started to receive 100 octane fuel, which pretty much agrees with the reported use of 100 octane fuel in several fighter squadrons starting from May 1940.

The 'certain' restristion was not limited to Bomber Command. Subsequent papers keep speaking of 'certain' concerned etc. fighter stations the same as 'certain' concerned bomber stations.

[41Sqn_Banks]

Originally Posted by Kurfürst

Only if you simply forget about the preceeding sentence - ""serving the fighter stations concerned". Its a quite clear constraint, repeated again in the April - May docs, posted previously.

"fighter stations concerned" could also mean all fighter stations with Hurricane, Spitfire and Defiant. But I agree with you that this is not clear and one can be read in both ways.

[Kurfürst]

Originally Posted by 41Sqn_Banks

"fighter stations concerned" could also mean all fighter stations with Hurricane, Spitfire and Defiant. But I agree with you that this is not clear and one can be read in both ways.

Theoretically it could, but then again, since all fighter stations had either Hurricane, Spitfire and Defiant anyway - what purpose would that serve..?

Secondly, about the two letters from December 1939. If we assume that the 24 Stations (if I counted right) listed there are indeed the ones that were said to be selected by ACAS in the March 1939 paper by the end of the year, that leaves a bit of problem, because there were about 60-odd fighter stations operated by Fighter Command in the Battle of Britain...

Which leaves if these were the ones effected, or 'concerned' it leaves about half of fighter command operating on 100 octane. A curious coincidence is that there are only combat reports indicating 100 octane supply for about half the Squadrons that participated in the Battle.

That leaves with a very well supportable case that half of Fighter Command was operating on 100 octane, and the other half on 87 octane.

Its not an easy case and I am thankful that as opposed to Fighter Command's case of 100 octane use, the Jagdwaffe's use of 100 octane fuel (naturally denied by lane, glider and minnie ) is so much more clearly documented and we know the very exact units, and the number of planes effected. Makes so much less room for arguements.

[lane]

Originally Posted by 41Sqn_Banks

The "approved stations" are given in the referenced letter No. F.C. 15447/76/E.Q.2:
http://www.wwiiaircraftperformance.o...0oct-issue.jpg
http://www.wwiiaircraftperformance.o...0oct-issue.jpg

Hi 41Sqn_Banks,

Those 7th December 1939 and 9th December 1939 directives list the stations requiring 100 octane fuel since they had or were expected to have in the near future Merlin engined aircraft. Non operational stations in Fighter command were also required to hold certain quantities of 100 octane.

The squadrons equipped with Hurricanes during December 1939 are as follows: 3, 17, 32, 43, 46, 56, 79, 111, 151, 213, 501, 504, 605.

During December 1939 these Hurricane Squadrons were stationed as follows.
3 – Croydon,
17 – Debden
32 – Biggin Hill
43 – Acklington
46 – Digby
56 – Martlesham Heath
79 – Manston
111 – Drem
151 – North Weald
213 – Wittering
501 – Tangmere
504 – Debden
605 – Tangmere

All these operational stations were listed on the 7th December 1939 or 9th December 1939 as requiring 100 octane fuel, therefore it was Fighter Command's clear intention that these Hurricane squadrons would convert to 100 octane fuel.

The Squadrons equipped with Spitfires in December 1939 are as follows: 19, 41, 54, 65, 66, 72, 74, 152, 602, 603, 609, 610, 611, 616.

During December 1939 these Spitfire Squadrons were stationed as follows:
19 - Duxford
41 - Catterick
54 - Hornchurch
65 - Northholt
66 - Duxford
72 - Drem
74 - Rochford
152 - Acklington
602 - Grangemouth
603 - Turnhouse
609 - Drem
610 - Wittering
611 - Digby
616 – Leconfield

Rochford is the only base not listed on the 7th December 1939 or 9th December 1939 directives, however, 74 Operations Record Book indicates that they had 100 octane while at Rochford in March 1940.

Other units participating in the Battle of Britain that converted to Hurricane, Spitfire or Defiant after December 1939 and the station where they converted are as follows:

64 – Church Fenton
92 – Croyden
145 – Croyden
222 – Duxford
229 – Digby
232 – Sumburgh
234 – Leconfield
242 – Church Fenton
245 – Leconfield
253 – Manston
257 – Hendon
263 – Drem
266 – Sutton Bridge
302 – Leconfield
310 – Duxford
312 – Duxford
601 – Tangmere

Sumburgh is the only base not listed in the 7th December 1939 and 9th December 1939 100 octane Fuel - Issue of directives to receive 100 octane fuel. 232 formed there in July 1940.

Therefore it can be readily seen that the operational stations at which the 100 octane fuel was required were all those stations that held operational Hurricane, Spitfire and Defiant squadrons.

Those units based in France during December 1939 were 1, 73, 85, 87 & 607 in Hurricane and 615 in Gladiator. We know from Post 372 that all these France based Hurricane squadrons were using 100 octane by May 1940.

This listing accounts for the 50 merlin engined Spitfire, Hurricane & Defiant squadrons that fought in the Battle of Britain.