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

[41Sqn_Banks]

Originally Posted by NZtyphoon

So he is trying to claim the Merlin III's maximum designed continuous power rating was +4 1/2 lbs at 2600rpm, and about 400hp.

I don't know if power at maximum continuous rating was 400hp, I've never seen a value for it. Rolls Royce always give International Rating, Maximum Rating and Maximum Take-off Rating. Sometimes Minimum Take-off Rating (this is at maximum allowed take-off boost with minimum allowed RPM, which is only important for fixed propellers).

Maximum continuous rating (1,15ata 2000 PRM) of DB601A was 810hp (@0km) to 860hp (@5km). As the maximum output is almost the same we can assume that the Merlin has a comparable power at continuous rating.

Here is the (not so serious) protocol from the design meeting at Rolls-Royce when they thought about their new high performance fighter engine. Engineer A is a daredevil, he likes fast, loud and dangerous stuff. Engineer B is a square and a careful engineer, he likes reliably stuff.
Engineer A: "I think with that design we should get 1,100hp maximum output. That's a great improvement compared to the 700hp of the Peregrine. Image how fast our fighters will fly with that. What do you think?"
Engineer B: "Hmm ... yes this should give about 800hp at a reasonable engine life of 100 hours between overhaul. I'm cool with that."
Engineer A: "Yeah whatever ... So we define our design goal as 1,100hp maximum and 800hp continuous output. Deal?"
Engineer B: "Deal! Let's do it!"

Later at Air Ministry ...

Engineer B: "This is our new engine design. We estimated it will will produce 800hp ..."
Engineer A: *facepalm*
Air Ministry: "What? The Germans build engines with 1000hp maximum output! You are useless!"
Engineer A: "May I interrupt? The 800 hp is the continuous rating, the maximum output will be 1,100hp."
Air Ministry: "... OK now that sound good. We want 900 engines delivered in 3 month. ... Oh and next time just tell me the maximum output. At Air Ministry we like fast, loud and dangerous stuff."

While leaving Air Ministry ...

Engineer A: "I told ya!"
Engineer B: "..."

[winny]

There's a book called "Britains war Machine" that I found last night. It contains a section devoted to the supply, use and production of 100 octane fuel.

It explains the whole Trimpell (Trinidad - ICI - Shell) refinery set up and says that the "shortage of 100 octane is a myth"

It's available as an e-book.

[Osprey]

Originally Posted by winny

There's a book called "Britains war Machine" that I found last night. It contains a section devoted to the supply, use and production of 100 octane fuel.

It explains the whole Trimpell (Trinidad - ICI - Shell) refinery set up and says that the "shortage of 100 octane is a myth"

It's available as an e-book.

ISBN number please?

[winny]

Originally Posted by Osprey

ISBN number please?

Britain's War Machine: Weapons, Resources and Experts in the Second World War - David Egerton
Hardcover: 464 pages
Publisher: Allen Lane; First Edition edition (31 Mar 2011)
Language English
ISBN-10: 0713999187
ISBN-13: 978-0713999181

It's on Amazon.
EDIT:
Here's the page I was refering to.



It then goes on to explain the sources of this fuel.
Kurfurst will hate it but the stock figures are from Gavin Bailey's paper..

[Crumpp]

I don't know where you are from Crump but there's no such thing as a standard day in England.

All - righty then....

[Crumpp]

If you intend to stick to this logic that's fair enough. As long as the engines in the sim produce correct amount of power at either of these settings used in real life, e.g. +6.25lbs. or +12lbs. as it is the case of early Merlins, I am happy.

MS gear is not Merlin II or III related btw. No matter how you look at it, the final result is exactly the same. And so is the reality that at this moment, what the title of this thread says is true, unfortunately.

All it does Robo is point out how much of an overloaded condition +12lbs was on the engine.

[Crumpp]

What the hell does 100/130 fuel, which wasn't even around during BoB, have to do with 100 octane fuel?

Do you know what 100 Octane fuel is, Milo?

[winny]

Originally Posted by Crumpp

All it does Robo is point out how much of an overloaded condition +12lbs was on the engine.

Desperate times call for desperate measures. There was a war on you know..

[Robo.]

Originally Posted by Crumpp

All it does Robo is point out how much of an overloaded condition +12lbs was on the engine.

RR approved overload during the war? Fair enough, should be in game.

[Crumpp]

In all of these publications 100 octane fuel and +12 is only a "minor footnote" and the "All out" limit is given as +6 1/4.

In the January 1942 edition it is definitely NOT a minor footnote. It is included in paragraph 1 above the operating limitations. They even specify January 1942 - ALL OPERATIONAL UNITS: 100 Octane ONLY



The technical order for this modification was not published until February 20, 1940.



This is not a minor modification nor is it an easy one from a manufacturing standpoint. Cylinder heads are a major component. Two heads have to be produced for every engine on the assembly line. All of the engines in the RAF inventory also have to have new cylinder heads produced as well. It is not going to happen overnight.

Milo Morani posted the instructions for Pilot Operating Notes earlier in this thread. The way it works is any technical instructions or service bulletins kept with the Operating Notes and act as updates as they are published.

When a new edition of the Operating Notes is published, all technical instructions issued since the previous Operating Notes edition are incorporated into the new edition of the Operating Notes.

That means we should see a mirror reflection of the January 1942 Operating Notes in our June 1940 edition if 100 Octane fuel was the standard and our technical instruction dated February 20, 1940 was intended for all operational aircraft.

Our June 1940 notes should alert the pilot in the operating that 100 Octane is the fuel for ALL OPERATIONAL UNITS just like the January 1942 edition IF 100 Octane is the standard fuel in use.

June 1940 Edition:





They do not reflect anything about 100 Octane fuel in the operating limits and nothing about it being for ALL OPERATIONAL UNITS.

This timeline of a gradual phase in of 100 Octane fuel begining in June 1940, becoming significant in October 1940, and operational conversion by December 1940 is evident from two sources.

You can see this in the Pilot's Operating Notes and the amount of fuel available at the airfields prior to June 1940. 100 Octane use is insignificant until October 1940. Proir to June 1940 we do not see a “combined” amount available at the airfields unless folks are now going to start claiming 100 Octane was in widespread use in 1938!!

I am sure that will be the next argument.