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

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All
I believe that a lot of frustration is being expressed and think it would be a good time to stand back, look at the overall picture and let people decide the strength of the two sides of the argument. This is best done by showing all the relevant papers in the time line so everyone can see how they fit together.

Before I start I will confirm my view that all of Fighter Command was effectively supplied with 100 Octane Fuel for the BOB, that the case is a strong one, but not, a perfect one. However all the following are supported by original documentation from the NA or from published works

16th March 1939 Meeting
Held to consider the question when 100 Octane Fuel should be brought into use in the RAF and the number and type of squadrons involved.

There are three main parts to this.
i) It is true that at this meeting authorisation was given for 16 fighter squadrons and two twin engined bomber squadrons be converted to be use 100 Octane fuel by September 1940. The change over to start at the end of 1939 and the ACAS would select the squadrons.
ii) It was anticipated that these units would use 10,000 tons of fuel over a twelve month period and this would slow down the aim of achieving an 800,000 ton reserve.
iii) The AMPD asked that he should be kept informed as to the progress of the production of the 100 Octane fuel in order that the change over of squadrons could be kept under review in the light of any acceleration or diminution in Supplies.

General Points
- Clearly this is a peace time plan, the war hadn’t started, 18 squadrons would use a lot more than 10,000 tons over twelve months when at war. It is certain that when war started there would be changes.
- It covers both fighters and bombers
- They were not defined as being Blenheim just twin engined bombers of which the RAF had a number of types.
- The 18 squadrons wasn’t a fixed number, it was open to change.

14th November 1939 letter Supplied by Kurfurst
The tests of 100 Octane in the Hurricane and Merlin
In this letter it mentions:-
i) That the tests were successful
ii) It is understood that sufficient stocks of 100 Octane are available
iii) That approval for use in Hurricanes and Spitfires should be given forthwith

7th December 1939 Letter from FC Admin to HQ
This letter starts going into the nuts and bolts of how the change from 87 to 100 Octane would need to be handled. It’s the sort of information any change of this magnitude will need.
The most interesting part is that it lists the 21 operational stations at which the fuel will be required in the first instance. At the time these were all the stations that were equipped or planned to be equipped, with Hurricanes and Spitfires. Also that training units would not be supplied with 100 Octane.

12th December 1939 Letter from Director Of Equipment re Issue of 100 Octane Fuel
Letter confirms that 100 Octane Fuel is approved for use in Spitfire, Hurricane and Defiant aircraft. Issue to be made as soon as the fuel is available at the distribution depots servicing the fighter stations concerned. Some bomber units may be given priority.
The date of use is dependent on when the fuel can be put down in bulk at the distribution sites and the relevant stations. Re the latter as a station empties a tank of 87 Octane it will be replaced with 100 Octane.

Observations
Clearly 7th and 12th papers are a change to the March 1939 notes. Certain aircraft are included and other aircraft in Fighter Command are excluded, no Blenheim fighter units are included or are any Gladiator units.
There is no limit set to the number of squadrons or area such as 11 Group, or any reference to specific squadrons. The RAF decided to use the 100 Octane and instead of limiting it to a number of squadrons, have decided to limit it by type of aircraft. All current and planned Spitfire and Hurricane bases are identified as being in the first instance.
Its worth commenting that Fuel was held at different levels, Strategic Reserves where they were imported, Regional level which is self explanatory, District Level which for FC was depots close to the Sector Stations and those at the individual satellite stations that were supplied from the Sector Stations. The method of distributing 100 Octane was to burn off the supplies of 87 Octane and as the tanks emptied to replace them with 100 Octane fuel. It takes time to use the 87 Octane Fuel in place, to make way for the 100 Octane so there isn’t a schedule roll out, the time will vary from station to station.

February 1940
The first combat reports are being recorded using 100 Octane and stations are also reporting the replacement of 87 Octane with 100 Octane fuel. Clearly the roll out is starting to reach the squadrons and one of the stations we have records for is Drem in Scotland and North Weald in the South of England. Drem is the last place I would change over to 100 octane, if there was a shortage of the fuel

24th February 5th Meeting of the Oil Committee
Request from ACAS that squadrons with Spits, Hurricanes and Blenheim should begin to use 100 Octane., no limitations.
Interesting choice of words as it is clear that some squadrons and bases have already converted and are using 100 Octane. However, there is a change in the replacement process they are discussing how to actively remove 3,600 – 4,000 tons of 87 octane fuel from station storage and replace it with 100 Octane, they are no longer waiting for the 87 Octane to be used up. The pace of change has increased.

6th April 6th Meeting of the Oil Committee
Progress Report on the change.
2 Group Bomber Command making good progress and want to have only 100 Octane on their bases. Agreement reached that four stations would only have 100 Octane and the others five sixths of fuel to be 100 Octane and one sixth 87 Octane.
Confusion in Fighter Command over the changes needed to operate 100 Octane. A Mr Tweedle is tasked with clarifying the situation with Fighter Command
There is also confirmation that the approved storage capacity of 800,000 tons is sufficient and that this tankage will hold between 640-700, 000 tons of fuel allowing for Ullage.
Definition of Ullage - the quantity of wine, liquor, or the like, remaining in a container that has lost part of its contents by evaporation, leakage, or use

18th May 1940 7th Meeting of the Oil Co ordination Committee Summary of Conclusions
The key points here are:-
i) The Committee took note that the position of the use of this fuel in Hurricane and Spitfire aircraft had been made clear to Fighter Command.
ii) Satisfaction was expressed that the units concerned had been stocked with the 100 Octane Fuel
iii) The Minutes were to reflect the appreciation of the work of the Petroleum Board and that the Air Ministry had been impressed with the manner in which the work had been executed.

May 1940 France
There are a number of papers detailing the roll out of 100 Octane to the RAF units in France. These were not in the original list of stations to be equipped and we have similar records for the RAF units sent to Norway.

Squadron Records Post May 1940
A number of RAF squadrons that took part in the BOB formed after May 1940, namely the commonwealth squadrons. None of the records that I have seen for these units mention any change over to 100 Octane and I checked these records until May 1941 by which time they would certainly be using 100 Octane. It’s my belief that this was because the use of 100 Octane after May 1940 was the norm.

1st August 1940 Memo from Downing re the Handling of the Merlin Engine
This note is advising the pilots that there is an increase in engine failures in the overuse of the emergency 12lb boost.
The interesting thing is that this memo was sent to ALL fighter groups. Had we been talking about the 16 squadrons or less this would not have been the case. It would have been sent to the squadrons involved.

7th August 1940
Note confirming that the Use of 100 Octane had been authorised for all Commands.This speaks for itself.


Reserves Information
The following information are the reserve stocks of 100 Octane fuel during the BOB period
This information has come from the War Cabinet Oil Position Monthly report (a) that is available from the National Archives, as well as Gavin Baileys paper(b) and Wood and Dempster(c).

Stocks of 100 Octane
30th September 1939 153,000 tons(b)
27th February 1940 220,000 tons(b)
31st May 1940 294,000 tons(a)
11th July 1940 343,000 tons(b)
31st August 1940 404,000 tons(a)
10th October 1940 424,000 tons(c)
30th November 1940 440,000 tons(a)

Point of interest. From the start of the war until the end of the BOB the reserves never dropped and continued to increase. There was never any danger of the supply of the oil running out, there is no record of any concern over the lack of 100 Octane fuel supplies, in the Air Ministry or the Oil Co ordination Committee, until May 1944.
From September 1939 small quantities of 100 Octane of under 1000 tons were held at Malta and Gibraltar

Consumption Information
The following information are the consumption details of fuel during the BOB period. This information has come from the War Cabinet Oil Position Monthly report that is available from the National Archives.

Consumption of Aviation Spirit
The following figures are for the Air Minstry and are the Average Monthly Consumption

September – November 1939 16,000 tons
Dec 1939 – February 1940 14,000 tons
March 1940 – May 1940 23,000 tons
June 1940 – August 1940 10,000 tons (100 Oct) 26,000 tons (87 Oct)
Sept 1940 – November 1940 15,000 tons (100 Oct) 18,000 tons (87 Oct)

Consumption was running at approx 21% of the Imports

Combat Reports
We have combat reports from over 30 squadrons showing the use of 100 Octane. Its worth mentioning here that the NA have changed access to the combat records. They used to be on microfilm so it was fairly easy to get the combat reports for a squadron and find an example. They are now available on line, but you have to pay to view each record and you cannot view them until you have paid so it becomes a very expensive business with many hundreds of records to look at. A price I cannot afford, but have little doubt that if we were to look at the other squadrons we would find similar records.

Important Note
All the above is supported by original documentation with the exception of my observation on the Squadron Records of Post May, I did look at a number but not all of those squadrons that is a fact but the interpretation is mine alone