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

[Kurfürst]

The current level of evidence for 100 octane use with all units of Fighter Command summarized:



+

[41Sqn_Banks]

Originally Posted by Kurfürst

Yes its seems possible - maybe the repro or the scanning person frankensteined together a couple of manuals.

Indeed, from what I've seen it contains at least amendments 6 and 9.

I did check "Vol. I" for references to IIB and found that the "Introduction" page was changed in June, 1941 to contain the difference between IIA and IIB. The changed part in the text is marked by vertical line.

And A.L. No. 19 from December, 1941 (see header of Section 1 Introduction) contains description of the different handling of IIA and IIB (Para 34a and b).

So I think it was June, 1941 when the difference between IIA and IIB was added to the manual.

[Al Schlageter]

It can be put to rest that the stations listed in the Dec 7 1939 document did indeed get 100 octane fuel, except possibly one.

10 Group

Filton
No. 151 Squadron Feb 1940
St Athan - training base

11 Group

Biggin Hill
No. 32 Squadron pre BoB H,
No. 610 (County of Chester) Squadron June 1940

Manston
600 squadron Blenheims

Marlesham Heath
No. 85 Squadron May 1940 H

Hornchurch
No. 41 Squadron June 1940,
No. 65 (East India) Squadron 12 Aug 1940,
No. 74 Squadron May 1940 S

Northholt
No. 43 (China-British) Squadron June 1940

Croydon
No. 111 Squadron pre BoB

Tangmere
No. 1 (Cawnpore) Squadron May 1940 H

Debden
No. 17 Squadron May 1940

Nowrth Weald
No. 56 (Punjab) Squadron May 1940,
No. 151 Squadron Feb 1940

12 Group

Duxford
No. 19 Squadron May 1940

Digby
No. 611 (West Lancashire) Squadron June 1940

Leconfield
No. 616 (South Yorkshire) Squadron 15 Aug 1940,
No. 249 (Gold Coast) Squadron 6 Sept 1940

Church Fenton
No. 73 Squadron May 1940,
No. 87 (United Provinces) Squadron May 1940 H,
No. 616 (South Yorkshire) Squadron 15 Aug 1940

Wittering
No. 229 Squadron May 1940 H

13 group

Drem
No. 602 (City of Glasgow) Squadron pre BoB

Turnhouse
No. 603 (City of Edinburgh) Squadron 31 Aug 1940

Grangemounth
No. 263 (Fellowship of the Bellows) Squadron

Acklington
No. 152 (Hyderabad) Squadron 4 Sept 1940,
No. 79 (Madras Presidency) Squadron May 1940 H,

Catterick
No. 41 Squadron June 1940

[Al Schlageter]

Originally Posted by Kurfürst

The current level of evidence for 100 octane use with all units of Fighter Command summarized:



+

When Barbi starts trolling, you know that he is squirming like a worm skewered on a fishing hook.

His 2cd image is of American 4 stack destroyers laying a smokescreen, which he is doing.

[Glider]

Originally Posted by Kurfürst

In short, the RAF recored in May 1940 that the issue of 100 octane was limited to select units.

All we have ever asked is for you to define select, which squadrons and support it so do so

[41Sqn_Banks]

Originally Posted by Kurfürst

Interesting. Do you what was changed with A.L. 31?

No, I think only that part and a para about air/sea rescue dinghy equipment. It's the last A.L. incorporated in the manual. It must have been between December, 1943 (the date of A.L. 30) and June 1944 (when the amendments were incorporated into the manual).

Another interesting point that it appears that +12 lbs was banned at that time for combat use ("5 min all out level"), the maximum allowed was +9, with +12 was only cleared for take off purposes up to 1000 feet. It appears that +12 was not cleared for combat use during the Battle of Britain, and was added only later.

Indeed interesting. The Merlin XX did have exactly the same limits when introduced, as can be seen here: http://www.wwiiaircraftperformance.o...s-10june40.jpg and was eventually increased to +12 boost in November, 1940, see:
http://www.wwiiaircraftperformance.o...xx-15nov40.jpg
And 3,000 rpm for climb above 20,000ft in December, 1940, see:
http://www.wwiiaircraftperformance.o...xx-11dec40.jpg

Also note that even the amended AP 1565 A Pilot's Notes for Spitfire I that comes with the Collector's Edition gives the "All out" limit with 3,000 R.p.m and +6 1/4 lb/sqn.in., and this is dated January 1942. The +12 boost is given under a own paragraph called "combat concessions" on the following page.

Also note that AP 1565 A Vol. I gives the +6 1/4 for "All out", however the description of the "boost cut-out" gives +12 boost. Note that A.L. No.6 is dated July, 1940.

the override control can be used for short periods only, but only when 100 octane fuel is used.

AP 1590B Vol. I Merlin II, III and V Aero-Engines A.L. No. 4 dated November 1940 also gives "maximum level flight (5 minute limit) of +6 1/2 but contains a detailed description of the +12 boost use for emergency.

It seems like there was a difference between "all out" and "emergency/combat" power (5min limit in the amended Spitfire II Pilot's Notes is called "combat" instead of "all out"). However, it would be interesting to find a reference when +12 boost and 3000 rpm for climb was actually cleared for the Merlin XII for combat/emergency. Possibly at the same time as higher limits were introduced for Merlin XX (November 1940 and December 1940).

[Glider]

Originally Posted by Kurfürst

Yes it's your belief and it's supported by nothing and specifically disproven by the documents you supplied yourself. These papers discuss in great lenght and express specifically that 100 octane is not meant for all stations, and specifically dismiss the suggestion to have only 100 octane at those stations which do not require it.

You need to be careful Kurfurst. The papers go to great length to say that the 100 octane is targeted in the first instance at the 21 stations which were all the stations that had Spitfires and Hurricanes at the time and we know that the RAF units in France and Norway were added to the list. Later your complaint is that is says it was targeted at all these stations but it did not get issued. However, your problem is that to aim for 21 stations is a change in the pre war statement of intent, something you say was carried out without alteration.

'Which were checked' seem to be keyword here. You checked but a handful of reports but mislead everyone here that there's no trace. The truth is you haven't checked it in a manner that would justify such claims.

This is your one comment which is correct. In two places on the posting I made it clear that I hadn't looked at all the squadrons and I didn't here.

Which it is, all the papers you have supplied follow exactly the schedule laid down by the March 1939 plan. Absolutely no indiciation or evidence have been presented that the plan was overidden at any time.

The problem here is that you do not know the details behind the paper. For instance, which squadrons, which bases, when, how does the the fuel get distributed. You cannot reply to these questions so it isn't a plan. A plan has etails that tell you how to get there, no detail no plan..
We do know that this aim was changed if only by the number of bomber units equipped with 100 Octane.

Nope, these 21 stations you keep mentioning from the December 1939 letters by FC are merely a list of stations where RAF FC would have liked to have 100 octane fuel.

This is where you need to make up your mind. If it helps Al matched 20 of the 21 stations to 100 Octane fuel in an earlier posting and as we know, those in France and Norway were issued with it as well.

In other words, you have absolutely no information or evidence to the extent of the roll out, or that it was unlimited, and you merely keep ignoring and dismissing every paper that specifically note that it was limited as 'pre-war plans' and 'mis-types'.

Its a theory but as I have pointed out, the pre war paper says 16 squadrons and we have over 30, its a problem for you.

We have discussed this. To put it bluntly, your claims about checking the War Cabinet decisions was a lie.

You know that I went through the War Cabinet files, I gave you the link, the file numbers concerned and even said I would help you if you had a problem. You have said that you have been through them and I am confident that you didn't find what you wanted, as you would have shouted it from the rooftops.

To now say I lied about going through the papers is a new low even for you.

This is a nice strawman argument. Nobody claimed that the there was a shortage of 100 octane stocks, however there were uncertainities with consistent supplies, partly due to U-boot activity and partly due to dependence on US manufacturers, their capacity and willingness; this is clearly noted by a dozen British historians like Morgan and Shacklady or the official studies. You ignore them all.

A couple of points:-
a) If there wasn't a shortage and we had a three year stockpile, why would the roll out be limited.
b) If there were uncertanties about supply, why did we halt production at the Billingham refinery because it wasn't needed
c) Please list the dozen Historians you refer to, or the official studies

You keep repeating this obvious nonsense. On one hand you claim the War Cabinet was one single body, and then you contradict yourself that 'a lot of parties reported to it'. The nonsense Glider repeats is that the War Cabinet had no Committes, and then he names the Oil Committee of the War Cabinet.

What I said is true. You have seen the minutes on the link I gave you,The War Cabinet is chaired by the PM, it has its own members. It isn't a committee, but organisations such as the Oil Committee and Air Ministry do report to it.
You did look at those files I gave you, didn't you?
If anyone would like me to reissue the details so they can check for the decisions Pips says were made by the War Cabinet and make their own mind up, please let me know.

I am curious of the evidence of the claims made in b). So which 'training units' had Spitfire Is and from where do you take they had no 100 octane fuel? Have you seen a document about it? A paper? A list of which units have 100 octane and which didn't?

OTU's had some Spitfires and Hurricanes and as Training units didn't have 100 Octane, so they used 87 Octane and papers have been submitted stating this. You have read the papers submitted haven't you?. The Luftwaffe used early 109's in a similar training role, I am sure.
I admit to not knowing where you are coming from here. Are you saying tht the RAF would give 100 Octane to training units, but not to front line units?

Well to cut the long story short, the only definitive evidence you have provided is that 100 octane was used by about 30 Squadrons out of 60, or about 20 Stations out of 50.

And that is just that, about 1/3 to 1/2 the units, so quite simply there's no factual basis, or evidence to, that all the others were using 100 octane. It's merely a wishful assumption.

I have explained about the change in the storage of the records and it is now very expensive to look at combat records. But 30 is a lot more than 16.

[NZtyphoon]

100 Octane Fuel Consumed

July - Aug 1940 = 20,000 tons consumed
Sept - = 14,000 tons consumed
Oct = 17,000 tons consumed
Total = 51,000 tons of 100 octane fuel consumed
1 imperial gallon of 100 Octane = 7.1 pounds ("Oil" by D.J Peyton-Smith the official British war history on the oil and petroleum industry during WW2 page xvii "Note on Weights and Measures"):

1 ton of 100 octane = 2,240 lbs therefore 2,240 divided by 7.1 = 315.5 imp gal

Fuel Capacities:

Defiant I = 97 imp gal
Hurricane I = 90 imp gal
Spitfire I & II = 84 imp gal
Blenheim IV = 199 imp gal outer fuel tanks
TOTAL = 470 imp gal divide by 4 = average fighter/bomber fuel load = 117.5 imp gal (Defiant from memory, so feel free to correct me. Defiant II = 104 imp gal)

1 ton = 315.5 imp gal divided by 117.5 imp gal = 2.6 fuel loads (or sorties) per ton of 100 octane fuel.

*This is assuming all aircraft emptied their tanks for each sortie, and assuming all aircraft shot down = 1 fuel load of 90.3 imp gal

NB: Not all aircraft returned with empty tanks and RAF policy was to refill each aircraft as soon as possible after landing, or each evening or early morning, to avoid vapour traps.

Merlin III & XIIs could still use 87 octane fuel, hence training flights and other secondary flight duties, such as delivery, ferry flights, etc could still use 87 octane fuel

July to August: 20,000 tons x 2.6 = 52,000 sorties
September: 14,000 tons x 2.6 = 36,400 sorties
October: 17,000 tons x 3.5 = 44,200 sorties
Total July-October 132,600 fuel loads consumed or 132,600 sorties in which all aircraft landed with empty tanks.


The Battle of Britain by T.C.G. James shows 51,364 sorties, day & night from July 10 through Sept 30; some of the most intensive combat took place between these dates. Of course there were quiet periods when far fewer combat sorties were flown by Fighter Command; eg: August 16 & 17, between two days of intensive combat August 15 & 18.

Hooton’s Eagle in Flames, Table 2, FC flew Sep 23-29: 4,825 defensive sorties Sep 30 – Oct 6: 1,782 defensive sorties.

Total = 57,971 sorties yet

In spite of Blenheims being mixed in there are still 74,629 fuel loads available.

OR

Originally Posted by Kurfürst

And that is just that, about 1/3 to 1/2 the units

were using 100 octane fuel = 19,323 to 28,985 sorties, either that or the aircraft using 100 octane fuel carried out all the sorties, leaving the rest, who were confined to using 87 Octane, to do other things.

Originally Posted by Kurfürst

And that is just that, about 1/3 to 1/2 the units, so quite simply there's no factual basis, or evidence to, that all the others were using 100 octane. It's merely a wishful assumption.

132,600 sorties - 19,323 to 28,985 = 113,277 sorties or 103,615 sorties unaccounted for, including Blenheim sorties Where did all that fuel go?

The only engines cleared to use 100 Octane were the Merlin II III and XII and the Bristol Mercury XV, so it wasn't Bomber Command or Coastal Command who used it all, nor was it Army Co-Operation Command.

[NZtyphoon]

Now, just for interest, this is assuming all Blenheims used 100 octane only (six Blenheim units may have used 100 octane in all tanks)

Blenheim = 479 imp gals
Defiant= 97
Hurricane = 90
Spitfire = 85
Total= 751 imp gals divided by 4 = 187.75

1 ton 100 octane = 315.5 divided by 187.75 = 1.7 fuel loads

20,000 x 1.7 = 34,000 fuel loads
14,000 x 1.7 = 23,800 fuel loads
17,000x1.7 = 28900 fuel loads
Total = 86,700 fuel loads - 57,971 = 28929 fuel loads left over

Even with all Blenheims theoretically using nothing but 100 octane fuel, there was still more than enough 100 octane fuel consumed - not issued - from July through end of October to supply 100% of FC, and some BC, operations. Once again this is also assuming all aircraft landed with empty tanks and had to be completely refueled, rather than being topped up.

But Wait there's More!!

According to Kf (attachment) the only British aircraft to fly during the Battle of Britain were those of Fighter Command and they managed to consume all of the "other grades" of fuel issued, and all of the 100 Octane!?

(Kf also says that consumption of "other grades of fuel went down starting mid to late September. Coincidentally that was the time that Operation Sealion was called off, and the collections of invasion barges that Bomber Command was running intensive operations against dispersed.

http://www.military-history.org/arti...n-timeline.htm

Except, according to the graph, Bomber Command wasn't operating.)

[41Sqn_Banks]

About +12 combat boost for Merlin XII I found a chart posted by Kurfürst which lists that boost. Unfortunately no date is given. National Archives Reference AIR 16/315.