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

[Crumpp]

The date of the Pilots Notes is not a definitive statement as was proved by Kurfursts version of the Mk II pilots notes which had an incorrect date.

I thought Kurfurst proved someone photo-shopped that version.

PS How are you getting on re the proving of 16 squadrons?

I have not seen anything that proves there were any more by September. What I have seen is misuse of information such as a single Inspection and Test certificate to build a case the entire RAF was using 100 octane or failure to explain an illogical use to reserve ratio.

Do you know what a Cylinder head spigot is?

In order to use +12lbs on the Merlin engine, you had to replace the heads with a new design with a increased spigot depth of .020. There were two authorized heads being manufactured to convert engines. One could use the existing rings while the other required a specific set of rings to be installed. Once that was done, the fuel metering system had to be modified. You can figure they would have had a 4 to 1 stock of heads before they started modifying aircraft. They would maintain that ratio even if it limited the size of the force they could convert.

In that memo dated 20 March 1940, it states this will be done as service maintenance. That means it was done on the equivalent of an annual inspection. So depending on when the aircraft made its service maintenance inspection is when it would be modified. Of course, Air Forces generally do it on an hourly basis such as 100 hrs, 200 hrs, 500 hrs up to 2000hrs. The Focke Wulf FW-190 was a 10/200hrs schedule for example. That is a 200 hour inspection can be done 10 times before the aircraft is sent depot level maintenance for overhaul.

[Al Schlageter]

Originally Posted by Crumpp

I have not seen anything that proves there were any more by September.

Quite dodging the question. What are squadron numbers for these 16 squadrons.

Fill in the blanks __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ .

[NZtyphoon]

Originally Posted by Crumpp

Spitfire Mk I Pilots Operating Notes, dated June 1940:



This is an Inspection and Test Certificate for a specific aircraft with a Merlin Mk III engine. Inspection and Test Certificate is probably the same as an FAA Form 337 allowing major modification for research or testing purposes. Note the document clears a single aircraft by serial number on 28 February 1940. The July of 1940 Spitfire Mk II manual clears the Merlin III engine for use of 100 Octane fuel and notes +12lbs may be used.

That is not the Spitfire Mk I but rather the Spitfire Mk II. There is nothing authorizing the Spitfire Mk I to use +12lbs in any of the Operating Notes.

And? All that it means is that the Pilot's notes, which you say were printed in June 1940, did not show 100 Octane fuel.

The problem is that any changes to the notes, before the next issue was printed, were altered through sets of amendments which were noted in the inner front cover of the book, and by gummed slips which amended the text in the appropriate locations. All this shows is that this particular set of notes was not amended. Look in the front cover of the notes and you will see this.

Better still how about showing all of us the front covers, including the inner fly leaf and index pages which show the date these notes were printed?

Attachment 3 shows that Merlins in Hurricanes of 151 Sqn had been converted to 100 Octane in February 1940.

The certificate, printed in February 1940, specifically discusses one aircraft, for sure, however, there are TWO problems:

1) There were no Mk II Spitfires in production in February 1940, and the engine is described as a Merlin III, although the power ratings suggest a Merlin XII which, as attach 1 shows, had been cleared to use +12.5 lbs boost.

2)Clearly this was a Spitfire I being used to either type test a Merlin XII or test a Merlin III at higher boost pressures. All it proves is that this particular certificate belonged to a test aircraft. How does this prove that this aircraft was the only Spitfire using 100 Octane fuel, and how did this lone Spitfire manage to chew through 52,000 tons of the stuff?

You have not explained why it is that there is a great deal of evidence showing that Merlin IIIs were modified and rated to use +12lbs boost and there are combat reports showing this. And why did Dowding feel compelled on 1 August 1940 to issue a general notice to all squadrons warning them against excessive use of +12 boost when only 16 Squadrons were using the fuel? http://www.spitfireperformance.com/dowding.pdf

[NZtyphoon]

Originally Posted by Crumpp

You can figure they would have had a 4 to 1 stock of heads before they started modifying aircraft. They would maintain that ratio even if it limited the size of the force they could convert.

In that memo dated 20 March 1940, it states this will be done as service maintenance. That means it was done on the equivalent of an annual inspection....So depending on when the aircraft made its service maintenance inspection is when it would be modified.

* AP1590B/J.2-W (attached) 20 March 1940 (the "memo") states that the modifications were "already being done" as service maintenance, with no mention of it being done as an "annual inspection" (nor does it mention the service intervals of aircraft) - the "annual inspection" is pure speculation on your part, with no evidence, as per usual.

* AP1590B/J.2-W goes on to say that "Newer engines will already have Mod.No.Merlin/136 embodied" meaning all production engines from March 1940 did not have to be modified because Mod No. Merlin/77 (modified spigots Merlin/64 plus modified piston rings) was incorporated on the production line as a production modification (Mod.No. Merlin/136). But you didn't mention that inconvenient fact - just another example of your misreading/misuse of documentation.

How many Merlin IIIs built before March 1940 would have still been in operational use by July? The modifications Mod/64,77 & 154 also applied to Merlin IIs not many of which would have been in service by July 1940.

Much of the rest of AP1590B/J.2-W describes modifications needed to the cut-out valve, then it sets out the engine's operating limits and is a general note for pilots.

* The comment about a "4 to 1 stock of heads" is pure blather and speculation on your part, with no documented evidence, and with no relevance to AP1590B/J.2-W.

Once again, for your benefit Crumpp:

*Explain how the RAF ensured that only 16 squadrons used the fuel - with documentation. Explain why at least 30 Squadrons - Hurricanes Defiants and Spitfires - report the use of 100 octane fuel when you insist only 16 squadrons used it - with documentation please.

*Explain what happened to at least 52,000 tons of 100 octane fuel with documentation.

*List the 16 squadrons authorised to participate in trials, with documentary evidence showing they were only participating in trials.

*Prove that the Merlin III was designed for only 400hp - with documentation.

All the rest is a smokescreen, showing your total lack of evidence for anything you say.

Originally Posted by Crumpp

I have not seen anything that proves there were any more by September. What I have seen is misuse of information such as a single Inspection and Test certificate to build a case the entire RAF was using 100 octane or failure to explain an illogical use to reserve ratio.

The only one misusing/misrepresenting information is your good self -

* You have not explained, for example, why the "use to reserve ratio" of Other Grades of aviation fuel, including 87 Octane, were lower during the battle than 100 Octane fuel, reserves of which continued to increase throughout?

Please answer these specific questions instead of dodging them, as per usual.

[28_Condor]

The writer Michael Korda, who served in the RAF, said in his latest book ("With Wings Like Eagles") that the RAF as a whole was served by american 100-octane fuel since 1939. And that was the advantage used against the German fighters that had fuel injection (but 87 octane fuel).

The British only really manufactured the fuel of 87 octane. It was Dowding who insisted that the British government to acquire the fuel from the Americans.

[41Sqn_Banks]

See this post for the relevant pages of AP1565A Vol. I that cover +12 Boost and 100 Octane.

http://forum.1cpublishing.eu/attachm...9&d=1332111633
http://forum.1cpublishing.eu/attachm...0&d=1332111638
http://forum.1cpublishing.eu/attachm...1&d=1332111649
http://forum.1cpublishing.eu/attachm...2&d=1332111659
http://forum.1cpublishing.eu/attachm...3&d=1332111666

Note Sec. 2 Para XII where the increase of boost to +12 is mentioned. Note Sec. 8 Para 7 the use is "authorized" for short period and when 100 octane is used. Also note the "List of Content" of Sec. 8, it shows Sec. 8 was issued with A.L. 6 in July 1940.

Originally Posted by Crumpp

In order to use +12lbs on the Merlin engine, you had to replace the heads with a new design with a increased spigot depth of .020. There were two authorized heads being manufactured to convert engines. One could use the existing rings while the other required a specific set of rings to be installed. Once that was done, the fuel metering system had to be modified. You can figure they would have had a 4 to 1 stock of heads before they started modifying aircraft. They would maintain that ratio even if it limited the size of the force they could convert.

Note that Sec. 8 Para 7 also refers to AP1590B Vol. I (manual of Merlin II and III) for the required modifications. IIRC in this manual only Mod 154 (modification that limits the boost to +12) is mentioned as required and the other modifications are recommended. I will look these pages up later. EDIT: The manual states that both mods are required.

Originally Posted by Crumpp

The July of 1940 Spitfire Mk II manual clears the Merlin III engine for use of 100 Octane fuel and notes +12lbs may be used.

Please correct this statement. It's unlikely that the Spitfire II manual (which has a Merlin XII engine) clears anything for the the Merlin III engine.

[Robo.]

According to some sources, the test certificate (this 'Page 40' document) is from testing of Merlin III improvements - of what has later become the Merlin XII. Unfortunately, without the rest of this paperwork (previous 39 pages) we can only assume what exactly is that all about I am afraid...

Anyway, knowing RR habit of testing and 'breaking' engines while improving parts that fail first to get more power, this makes perfect sense to me. Ratings of both Merlin XII and Merlin III are well documented and researched - Merlin in perspective pg. 155 and onwards states all ratings according to improvements along from III to XII:

R.M.1.S. (Merlin III)

combat power: 1310hp, 3000rpm, 9000ft., +12lbs
(combat power: 1440hp, 3000rpm, 5500ft., +16lbs - Sea Hurricane only)
take off: 880hp, 3000rpm, +6.25lbs.
cruising: 2600rpm, +4.5lbs.
climbing: 2600rpm, +6.5lbs.

R.M.2.S. (Merlin III, as R.M.1.S. but with increased take-off power on 100 octane fuel, superseded by the use of combat ratings on R.M.1.S.)

combat power: 1000hp, 3000rpm, 15500ft.,+6.25lbs.
take off: 1000hp, 3000rpm, +8.25lbs.
cruising: 2600rpm, +4.5lbs.
climbing: 2600rpm, +6.5lbs.

R.M.3.S. (as Merlin IV but higher supercharger gear ratio (note was 8.588 on Merlin III, is 9.089 on Merlin XII) and 100 octane fuel. For Spitfire II)

combat power: 1280hp, 3000rpm, 10500ft.,+12lbs.
take off: 1175hp, 3000rpm, +12.5lbs.
cruising: 2650rpm, +7bs.
climbing: 2850rpm, +9lbs.

R.M.4.S. was regarding further improvements on Merlin XII, but was never production type; superseded by Merlin 45

[Glider]

CRUMPP
Your reply doesn't give the additional pages of the pilots notes that would give some indication as to the type of Spitfire we are looking at.

Can you give us a link to the rest of the pilots notes so we can review them in detail. You will understand as the sheet from the pilots notes shown don't mention a date.

As I said if it doesn't mention the fuel then it almost certainly refer to an early version of the Spitfire. By June 1940 we know from combat and squadron records that 100 octane was in use and this would be reflected in the pilots notes.

One last thing, where do the pilots notes state 400 hp? or have we dropped that theory?

[Al Schlageter]

Glider, it is even less HP than that. Morgan and Shacklady in Spitfire: The History gives 990 hp for early Merlin engines. So that would be 330hp according to Eugene's generalization.

Eugene is a little short on specifics, isn't he? But that is understandable when a document shows a times 2.5 increase in hp over what he claims at a lower boost level. Until he comes up with specifics, it is only so much smelly shovel from him.

I have not seen anything that proves there were any more by September. What I have seen is misuse of information such as a single Inspection and Test certificate to build a case the entire RAF was using 100 octane or failure to explain an illogical use to reserve ratio.

So squadron log books and pilot reports are garbage. Sure.

Quite dodging the question. What are the squadron numbers for those 16 squadrons.

Fill in the blanks __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ .

[NZtyphoon]

Originally Posted by Al Schlageter

Until he comes up with specifics, it is only so much smelly shovel from him.



So squadron log books and pilot reports are garbage. Sure.

Quite dodging the question. What are the squadron numbers for those 16 squadrons.

Fill in the blanks __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ .

And while you're about it Crumpp,

* Please explain why the Merlin III was cleared to use +12lbs boost, and instructions were issued for all Merlin engines to be modified to use 100 octane fuel and +12lbs boost in November 1939? Please explain what "it is understood there are adequate reserves of [100 Octane] fuel for this purpose." means?

* Please explain why it was that several squadrons were using 100 Octane fuel in February 1940? Then explain when the RAF decided to restrict the fuel's use to operational trials. Properly documented, of course.

* Please provide documentation showing that the RAF was engaged in nothing more than "operational trials" from Feb - Sept 1940.

*Then explain why A.P1590B.J.2-W states that all production engines from March 1940 were fitted with the necessary modifications on the production line, contradicting your convoluted explanation that a limited number of Merlins might have been modified, based on a 4 to 1 head reserve?

* Please provide documentary evidence that a reserve of 4 heads to 1 was required by the RAF?

* Please explain why Hurricane squadrons based in France used 100 Octane fuel operationally during May 1940, when you insist the RAF needed to use 16 squadrons to engage in "operational trials" up to September.

* Then please explain why you now insist that no Spitfire Is used 100 octane fuel, based on a single, so far undated, set of pilot's notes, when there are squadron and combat reports clearly showing that emergency +12 lbs boost was used by Spitfire, Hurricane and Defiant units?

* Please explain the administrative and logistical arrangements FC put in place to ensure that only 16 squadrons were able to use 100 octane fuel.

* Please explain what happened to at least 52,000 tons of 100 octane fuel. Provide documentary evidence showing that the stuff was merely sent back to reserves, was stored, or rejected for use.

You have been asked several times to come up with some decent evidence to prove that your speculative spin is correct - instead all we have been treated to is your usual evasion and evidence avoidence. Please, stop wasting everybody's time, including your own.