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

[Crumpp]

then how did 611 Sqn convert in Feb?

Wrong question....

How did they know all the technical answers to publish instructions in March?

Answer....

They tested it over a period of time in a number of aircraft to get the data required.

Total consumption for the whole of the BoB didn't come anywhere near what was in stock before the BoB started.

Not at the required consumption to stock ratios....

Pretty much ends my conversation with you so I will put you back on the ignore list.

[28_Condor]

Frankly, it is very difficult to follow this discussion ...

For me it is easier to understand articles that have reviewed the literature and where I can draw conclusions:


Palucka, Tim. The Wizard of Octane. American Heritage of Invention & Technology, 20. 3 (Winter 2005): 36-45.
Resume: IF, AS THE DUKE OF WELLINGTON IS SUPPOSED TO HAVE SAID, the Battle of Waterloo was won on the playing fields of Eton, then one can assert with equal justice that the Battle of Britain was won at the Stevens Hotel, in Chicago, on November 18, 1938. It was there, at the annual meeting of the American Petroleum Institute, that Arthur E. Pew, vice president and head of research of the Sun Oil Company, described his company's extraordinary new catalytic refining process. Using it, he said, Sun was turning what was normally considered a waste product into gasoline-and not just ordinary gasoline, but a highoctane product that could fuel the era's most advanced airplanes. That process would make a crucial difference in mid-1940, when the Royal Air Force started filling its Spitfires and Hurricanes with 100-octane gasoline imported from the United States instead of the 87 octane it had formerly used. Luftwaffe pilots couldn't believe they were facing the same planes they had fought successfully over France a few months before. The planes were the same, but the fuel wasn't. In his 1943 book The Amazing Petroleum Industry, V. A. Kalichevsky of the Socony-Vacuum Oil Company explained what high-octane gasoline meant to Britain: "It is an established fact that a difference of only 13 points in octane number made possible the defeat of the Luftwaffe by the R.A.F. in the fall of 1940. This difference, slight as it seems, is sufficient to give a plane the vital `edge' in altitude, rate of climb and maneuverability that spells the difference between defeat and victory."

Bailey, Gavin. The Narrow Margin of Criticality: The Question of the Supply of 100-Octane Fuel in the Battle of Britain. English Historical Review; Apr2008, Vol. 123 Issue 501, p395-411, 17p, 3 Charts
Resume: The article focuses on the supply of 100-octane fuel during the battle of Great Britain. Aviation historians have advanced the supply of 100-octane aviation fuel as critical American contribution to the battle. A study of the contemporary Air Ministry records in the Public Record Office shows that this assertion can be challenged. The challenge can be made on the grounds of the aircraft performance benefit involved, as showed by contemporary Royal Air Force (RAF) testing, and on the national origin attributed to 100-octane fuel supplies. The records reveal that contrary to the assertion of aviation history, the supply of 100-octane fuel to RAF in time for use in the battle must be attributed to pre-war British planning and investment on the rearmament period of the late nineteen-thirties.

My only conclusion is that only in this forum I read the statement that 100-octane did not have a role in the Battle of Britain (statement supported by the devs? ) ... and not supported in a peer-reviewed article...

[NZtyphoon]

Originally Posted by Crumpp

Who said anything about overhauling the aircraft?

You did, right here:

Originally Posted by Crumpp

A technical order for conversion of the aircraft had not even been published at that time. It is highly unlikely that the RAF was in the process of widespread conversion to 100 Octane without disseminating the technical knowledge to convert the airplanes in the force.

Originally Posted by Crumpp

There is no misrepresentation and the language is quite similar to Service Bulletins and Airworthiness Directives in use today.

It clearly states the two methods of compliance by part number with the technical order and specifies which one will be incorporated in future production engines. The 900(+) Single Engined fighters using the Merlin already in service will have to be converted along with the maintenance stock of Merlin engines.

It means they have to manufacture quite a few new cylinder heads and rings. That is why the conversion will take place during the cyclic service inspection.

You have no idea what technical service documents were published between November 1939 and February 1940, so claiming that none had been published is completely wrong.

The designation AP1590B J.2-W indicates that there were documents before this one

Read AP1590B J.2-W properly Crumpp - it refers to older production Merlins

Paragraph 4 states[B]

1) .Mod.No.Merlin/77 is already being done as service maintenance "is already being done" means that the parts and the information needed was available before March 1940.

2)"Newer engines will already have Mod.No.Merlin/136 embodied" "Will already" means that production engines built before March 1940 incorporated the modifications.

Originally Posted by Crumpp

7. In October of 1940, the United Kingdom as just half the Strategic Reserve required of 800,000 tons. In other words, there is a shortage of 100 Octane fuel in the United Kingdom.

Once again utter nonsense. You are still obsessed with a pre-war document to decide what happened in wartime when a country was under attack. Reserves of 100 Octane never reached 800,000 tons - in 1941, when all services had converted to the fuel, reserves reached a peak of 527,000 tons in February before steadily declining.

Originally Posted by Crumpp

Not at the required consumption to stock ratios....

Strategic reserves of "Other Grades", including 87 Octane fuel, got far lower than 100 Octane in August 1940; 230,000 tons cf 404,000 tons of 100 Octane. Your "required consumption to stock ratio..." is completely erroneous

August 1940

Consumption of "Other Grades" = 26,000 tons plus reserves of 230,000 tons = 256,000 tons of other grades. Heavy bombers, flying boats etc were still consuming 87 Octane fuel considering that big aircraft with big fuel tanks were using the fuel the difference in consumption is a little easier to understand.

Consumption of 100 Octane
10,000 tons plus 404,000 tons in reserves = 414,000 tons of 100 Octane

Get it clear in your mind Crumpp - only 15,000 tons of fuel was needed to cover all operational defensive sorties flown by Merlin powered aircraft of Fighter Command right through the battle. You have never explained what happened to the remaining 36,000 tons of 100 Octane fuel consumed, and you never will. Instead, as per usual, you continue to evade some very basic questions.

[Al Schlageter]

The testing had been done long before mass conversions began early in 1940.

http://www.wwiiaircraftperformance.o...t-approval.jpg
http://www.wwiiaircraftperformance.o...octanefuel.jpg

Then there is the document of Dec 1939 for stocking of 21 operation bases and 18 other bases with 100 octane fuel.

http://www.wwiiaircraftperformance.o...0oct-issue.jpg

Notice North Weald is one of those stations. How many times have we heard from you that no mods could be done without proper documentation/orders? So 611 Sqn must have done the conversion without proper authorization.

However did RAF FC conduct operations after Oct 1940 when 100 octane fuel was the fuel of FC as it still hadn't reached 800,000 reserve tons?

As can be seen there was no worries about 100 octane fuel,
http://www.spitfireperformance.com/1...e-2april40.jpg

Even at the end of 1941 there still wasn't a reserve of 800,000 tons.



We have yet to see the identity of these 16 fighter squadrons from you Eugene.

[Crumpp]

"Will already" means that production engines built before March 1940 incorporated the modifications.

There is nothing in that technical bulletin that reads engines produced before March 1940 will have the modification.

Once again, if it was the standard fuel in service, the Operating Instructions would reflect that.

They would not continue to publish 87 Octane Operating limits with scant references to the ability to use 100 Octane. They would publish the 100 Octane limits and the 87 Octane would be a foot note or a supplemental instruction.

Where is the 100 Octane fuel at the airfields in March??

[Al Schlageter]

Where is the 100 Octane fuel at the airfields in March??

Some must have been at North Weald for 151 Sqn and 611 Sqn.

Some must have been at Drem for 111 Sqn.

[Glider]

Someone needs to learn how to read a chart. The 23,000 ton figure for Mar to May 1940 is in the centre of the chart and is a combined figure for 100 and 87 octane fuel.

[Al Schlageter]

Originally Posted by Glider

Someone needs to learn how to read a chart. The 23,000 ton figure for Mar to May 1940 is in the centre of the chart and is a combined figure for 100 and 87 octane fuel.

More like just learn to read.

[Glider]

Error

[Crumpp]

611 Sqn

They were not using 100 Octane at least by the log entry posted in this thread.

combined figure for 100 and 87 octane fuel.

The footnotes would point that out.

Clearly, 87 Octane is the only aviation fuel available before June 1940.

Once again, this is reflected in the Operating Instructions as well.

If 100 grade was the standard, it would be the standard in the Operating Instructions.