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

[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.

[Seadog]

Originally Posted by Kurfürst

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.

Show us evidence of a single operational sortie using 87 octane fuel flown by a front line RAF FC Spitfire or Hurricane squadron during the BofB.

[Seadog]

Originally Posted by Seadog

Show us evidence of a single operational sortie using 87 octane fuel flown by a front line RAF FC Spitfire or Hurricane squadron during the BofB.

Kurfurst, I'm still waiting...

[Al Schlageter]

Originally Posted by Seadog

Kurfurst, I'm still waiting...

It shouldn't be that hard for Barbi, or Eugene, to do so as there was only 16 squadrons out of 50 plus that used 100 fuel, according to them.

[NZtyphoon]

Originally Posted by Kurfürst

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...

Wrong again: as of September 1940 there were 19 Sector stations and 23 Satellite aerodromes = 42 bases: * = requiring 100 octane as of December 1939; # = bases not operational in December 1939: NB: 10 Group was not formed until 1 June 1940 http://en.wikipedia.org/wiki/No._10_Group_RAF

Sector Stations:
10 Group: Filton* (listed as operational 9th December 1939), Middle Wallop#

11 Group: Tangmere*, Biggin Hill*, Hornchurch*,
North Weald*, Debden*, Northolt*,
Kenley* listed as non-operational, requiring 100 Octane 7th December 1939#

12 Group: Duxford/ Fowlmere*, Wittering*, Digby*,
Kirton-In-Lindsey, Church Fenton*

13 Group: Usworth, Acklington*, Turnhouse*, Wick and Dyce

Satellite aerodromes

10 Group: Boscombe Down, Colerne, Pembry, Warmwell#,Exeter#

11 Group: Westhampnett*, Croydon*, Gravesend,
Rochford*, Manston*, Hawkinge, Martlesham
Heath*, Hendon*, West Malling#, Stapleford
Tawney#.

12 Group: Coltishall, Turnhill, Leconfield*

13 Group: Catterick*, Drem*, Grangemouth*, Kirkwall, Sumburgh*

http://en.wikipedia.org/wiki/RAF_Fig...of_Battle_1940

attachment: Combat Report Boyd 602 Sqn showing Westhampnett as using 100 octane. August 1940

From the Battle of Britain Then and Now Vol V:

Westhampnett was "...an emergency landing ground for the fighter squadrons based at Tangmere...during the month of July 1940 it gradually assumed the status of a satellite landing ground..." (p. 42.).

Kenley was under a programme of reconstruction and expansion from May - December 1939. (p. 46.)

The following bases had not been established in December 1939:

*West Malling was a private aerodrome and did not become an official RAF station until June 1940. (p.70.)

*Stapleford Tawney did not receive its first operational fighter squadrons until March 1940, when 56 and 151 Sqns used it as a stopover. (p. 184.)

*Duxford and Fowlmere have to be considered together "as the latter had no separate identity..."(p.198.)

*"RAF Station Exeter was officially inaugurated in the presence of Nos. 213 and 87 Squadrons on July 6 1940."(p. 213.)

*Middle Wallop was a training aerodrome until becoming an operational fighter base on 12 July 1940. (p.218.)

*Warmwell was also a training aerodrome and did not become an operational fighter base until July 4 1940. (p. 231.) 609 Sqn was based firstly at Northolt then moved to Middle Wallop on July 4 and used Warmwell as a daytime base.(p.231.) The Spitfire maintenance film was made at Northolt in mid June 1940.

*Filton was later a 10 Group Sector station but only ever hosted one or two squadrons at a time, only one of which - 501 Sqn. - required 100 Octane fuel.

"Squadrons stationed at RAF Filton from the beginning of WW2 included 501 (County of Gloucester) Sqdn (Auxiliary Air Force), now flying Hawker Hurricane I fighters, until 10 May 1940 when that Squadron moved to France; and 263 Squadron (reformed on 20 October 1939 at Filton) taking over some of the Gloster Gladiator I biplane fighters previously with 605 Squadron and still wearing that squadron's code letter (HE). The Squadron went on to Norway in April 1940 operating from a frozen lake.

Between May and July 1940, No. 236 Squadron were based at Filton with Bristol Blenheim twin-engined fighters, flying defensive sweeps over the Channel." (source http://en.wikipedia.org/wiki/RAF_Filton)

In December 1939 there were 36 operational bases, because Fowlmere was an integral part of Duxford.

All of the 6 operational and 1 non-operational 11 Group sector stations were to be provided with 100 octane fuel;

12 Group: 4 out of 5

13 Group: 2 out of 5

10 Group: 1 out of 2

6 out of 8 "satellite' airfields in 11 Group were to be provided with 100 octane fuel;

12 Group: 1 out of 3

13 Group: 4 out of 5

10 Group: 0 out of three

25 out of 36 operational bases were to be provided with 100 Octane fuel starting in December 1939, a ratio of better than 2 to 1.

Far more realistic than 24 out of "60 odd" stations.