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

[Talisman]

Originally Posted by Bounder!

Simply put, as I understand it from reading the various threads on this forum plus the threads on ww2aircraft.net linked by Klem on page 9 of the Spit MK I/II thread, RAF fighter command's Spitfires and Hurricanes flew combat sorties using 100 Octane fuel during the Battle of Britain - there is ample and overwhelming evidence for this backed up by references linked; there has been no evidence provided backed up by a reference for the use of 87 Octane fuel by Spitfires or Hurricanes during BoB. So simply put, in a combat flight sim of BoB, Spitfire and Hurricanes should be modeled using 100 Octane fuel.

Well said Bounder. Is there anyone out there that would disagree with Bounder?

Bounder, I respectfully suggest that you could be accused of applying intelligent, reasonable logic; however, such thinking is not acceptable to a 100 Octane denier.

The burden of proof in a UK criminal court is “beyond all reasonable doubt”. Given the evidence, I believe that RAF Fighter Command would be found guilty of premeditated and wide spread use of 100 Octane fuel by a jury of 12 good citizens of sound mind. LOL. Moreover, in a civil court, with the burden of proof being “on the balance of probability” the RAF would have been locked up long ago!

Happy landings,

Talisman

[Blackdog_kt]

I can understand a passionate discussion guys, but keep the emotions in check if it starts to get too personal.

I've had reported posts about namecalling and personal attacks in this thread, so i urge everyone to go back 3-4 pages and see if they have any in their posts and then edit them out before the moderating team has to step in and issue infractions.

On the matter at hand, the best way to solve this debate is to model both versions. It's not like they are useless to have: in a dynamic campaign (either offline or online) there will be cases where 100 octane supplies will be low due to enemy action.

For people that want an exact day-to-day recreation of BoB then yes, the most widespread version is the only one they will need.

However, there's a large amount of users who are interested in a dynamic campaign. That definitely needs both versions, because otherwise there's no real incentive to go after the opponent's fuel supply, essentially cutting off a pretty vital part of strategic bombing objectives and throwing it out of the picture.

Better yet, each one can use what they want offline or fly on the servers that use what they prefer when going online, instead of trying to convince each other in the hopes their favorite ride will be better.

I really don't get why we should restrict everyone to a single way of doing things, especially when both fuel types actually existed in the first place.

Like i said, many people want things in the sim to be exactly like they were in the 40s. Many however want the conditions to be the same, but they also want the ability to change the outcomes somewhat. Bomb the enemy's supplies of 100 octane to make their fighters intercept you with more difficulty, so you can then move on to bombing other targets with reduced casualties and so on. It's a whole extra layer of interesting tactical considerations that would be a must for any dynamic mission environment.

Having only 87 oct or 100 oct is not conducive to that. So why should these players be limited in their enjoyment of the product when the first group has nothing to lose by the inclusion of both versions (they can simply choose which version to fly)?

[Kurfürst]

Pretty much agree on all your points.

Anyway I've always said that both 87 and 100 octane versions would be nice to be implented in the sim. As you noted, having two versions is better for all. It allows for dynamic campaigns, it does not restrict the hands of mission designers or server hosts to decide what versions of planes they want to have in. It allows OPTIONs.

The only loosers are the small group who wants to set their version of history to all in stone, and having only the bestest planes to fly for one side. And its a miniscule group compared to the entire group.

[41Sqn_Banks]

Petrol rationing in Australia during the Second World War

[TomcatViP]

Well at least, what we hve shown lately with our research in th Au archives is that :

- there was 100 oct fuel ordered and delivered
- This fuel was used ONLY to be blended with old stock of 74 octane fuel to create adequate 87, 90 or 95 octane fuel
- The stoichiometry of the blend is defined in the archive
- To be blended adequately, some specified additives where requested and delivered by the oil companies
- There was no plane in Australian air force that needed a single drop of pure 100 octane fuel as of feb 1941

What we also learned is that the cost of 100oct fuel was stated after some negotiations at 18 cents a gallon

my 1/9th gallon (of 100octane of course)

[Osprey]

@Kurfurst. I believe you could learn from the "Russells Teapot" argument.

http://en.wikipedia.org/wiki/Russell's_teapot

I'm not interested in the flaky Australian argument anymore since it appears far too unconvincing and more importantly, irrelevant. It matters not even if, as you suggest, that the UK wouldn't give the Australians any 100 octane because they were short. That is not evidence that the RAF didn't have enough to use themselves.

We can use simple logic to decide the truth here. I ask you, do you deny any of these 4 points listed?

1. That the RAF used fuel.
2. Every flight recorded a combat report (provided the pilot returned).
3. That the fuel type or boost to indicate the type was frequently mentioned in combat reports throughout the BoB.
4. That 87 is never ever mentioned and 100 was in every case.

Therefore the entire RAF MUST have used 100 in in combat and no other type. It really is that straightforward. What I do not find straightforward are your reasons for objection. Please, what are they?

[NZtyphoon]

From KF in another post: http://forum.1cpublishing.eu/showthr...rst#post378110

Now, despite being perfectly aware that he needs to contact this Australian guy, Glider kept b!tching to me about producing the paper, of which I have only seen a summary on a board. I kept telling him to contact Pips and ask him.

"...I have only seen a summary on a board..." Kf has not actually seen the original, but it is guaranteed to be 100 percent accurate.

'Nuff said.

[Blackdog_kt]

Originally Posted by Osprey

@Kurfurst. I believe you could learn from the "Russells Teapot" argument.

http://en.wikipedia.org/wiki/Russell's_teapot

I'm not interested in the flaky Australian argument anymore since it appears far too unconvincing and more importantly, irrelevant. It matters not even if, as you suggest, that the UK wouldn't give the Australians any 100 octane because they were short. That is not evidence that the RAF didn't have enough to use themselves.

We can use simple logic to decide the truth here. I ask you, do you deny any of these 4 points listed?

1. That the RAF used fuel.
2. Every flight recorded a combat report (provided the pilot returned).
3. That the fuel type or boost to indicate the type was frequently mentioned in combat reports throughout the BoB.
4. That 87 is never ever mentioned and 100 was in every case.

Therefore the entire RAF MUST have used 100 in in combat and no other type. It really is that straightforward. What I do not find straightforward are your reasons for objection. Please, what are they?

Like i said, i want both versions in the sim but ok, i'll bite and play devil's advocate here just for the sake of showing you guys what i get from the whole discussing here. Lets go ahead and take each numbered point one by one, shall we?

1. Correct
2. Correct
3. Correct, the operative word being "frequently". Which could mean it was a differing practice (to be mentioned in the first place) but widespread enough (to be mentioned frequently).
4. Correct. Which could mean 87 wasn't mentioned because it was the default, while 100 was mentioned because for one it was the exception to the rule and secondly, extra boost warranted extra inspections by the mechanics.

I'm not arguing either case, this is just an example to show everyone here how flaky the whole thing appears to an outside observer, no matter which side of the argument one tends to support.

I just think no side has provided any undisputed facts: i see a lot of credible sources in this thread but far too often a lot of them are conflicting, with no real means to discern which i should "believe more". I'm not convinced either way and that's why (as well as the dynamic campaign considerations) i advocate the presence of both types for all aircraft that use higher grade fuel during the BoB.

I remember seeing similar evidence about half the 110 units being also equipped with better fuel and higher rated engines. I want to have both versions, no matter if its a Spit or Hurri or 110. Forgive me when i say that i doubt some of the most invested posters in this thread would do the same, as i have a suspicion that many who support 100 octane Spits would denounce DB601N-equipped 110s and vice versa.

Let's have options is all i'm saying

[TomcatViP]

In the series of " What archives tells us" here is the FLIGHT archives that I cited two days ago :

- There was no 100 octane fuel usage during BoB in the FC. Here I am putting my money on British pride that would hve pushed forward any of its usage (ok Brits are not French but never the less )

- in 1941 increased power Merlin's had 9lb boost level

- 100 oct fuel was used by some aircraft in the RN (Fulmar) fitted with special engines such as the Merlin VIII (presumably to compensate for the extra weight of the 2nd crew member and low alt missions)

- In 1941 planes were still using 87 octane such as was the Hurricane with Merlin XX

Sources : (http://www.flightglobal.com/pdfarchi...0-%201286.html)

1. "International power of the Merlin I and II was 950/990 h.p. at
2,600 r.p.m. at 12,250ft, and the maximum take-off output was
890 h.p. at 2,850 r.p.m."

2. Merlin III : "The power output of the standard engine,"
writes Harold Nockolds, "was 1,030 b.h.p. at 3,000 r.p.m. at
10,250ft with plus 6i lb boost. "

3. "the petrol normally used at that time was 87
octane"

4. "The Merlin II and I I I were installed in the Spitfire I, Defiant I,
Hurricane I, Sea Hurricane I, and Battle I, and were—as will
always be remembered—vital factors in the winning of the Battle
of Britain. The Merlin IV had pressure-water cooling in place
of the glycol cooling of the earlier models, and was developed
for installation in the Armstrong Whitworth Whitley IV bomber.
The Mk VIII, installed in the Fairey Fulmar I, was a medium supercharged
unit rated at 1,010 h.p. at 2,850 r.p.m. at 6,750ft,
and, using 100-octane fuel, delivered 1,080 h.p. at 3,000 r.p.m. for
take-off."

5. "The Merlin X—installed in the Halifax I, Wellington II and
Whitley V and VII—represented a very important advance in
that it had a two-speed supercharger to improve take-off, lowaltitude
performance during climb or level flight, and fuel
economy under cruising conditions. The speed change was
effected through an oil-pressure system, the actual changeover
under full power taking about a second. In low gear the Merlin X
gave 1,145 h.p. at 5,250ft, and in high gear 1,010 h.p. at 17,750ft."

6. "The Merlin XII, driving a Rotol three-blade constant-speed
airscrew, was installed in some Spitfire lls ; its maximum output
was 1,150 h.p. at 3,000 r.p.m. at 14,000ft and it had a 0.477:1
reduction gear."

7. "The next production-type engine was the Merlin XX, which,
compared with the X, delivered a greatly increased power at
height." [...] "Thus, using 100-octane fuel,
the international rating in low gear was 1,240 h.p. at 2,850
r.p.m. at 10,000ft and plus 9 lb/sq in boost; in high gear the
figure was 1,175 h.p. at 2,850 r.p.m. at 17,500ft, again at plus
9 lb boost."

8. "The Merlin XX powered the Beaufighter II, Defiant II, Halifax II and V, Hurricane II and IV, and Lancaster I and III."

9. "An increase in take-off output from 1,300 h.p. to 1,600 h.p. characterized
the Merlin 32, which powered the Barracuda II and
Seafire II."

10. "A variant which saw very extensive service was the Merlin 45,
fitted in the Spitfire V, P.R.IV and VII, and Seafire I I ; at 16,000ft
and 2,850 r.p.m. its output was 1,200 h.p. The Merlin 45M was
rated for duty at lower levels and delivered 1,585 h.p. at 2,750ft;
it was fitted in the Spitfire L.F.V"

11. "The Merlin 46 and 47 were
both high-altitude engines (1,115 h.p. at 19,000ft); the 46 powered
the Spitfire V, P.R.IV and VII, and Seafire I, and the 47 (which
had a cabin supercharger) found its application in the Spitfire VI."

12. "The key feature of the Merlin 61 was its two-speed, two-stage
supercharger, with two rotors on a common shaft. The mixture
was compressed by the first stage and was delivered to the inlet of
the second stage, where it was further compressed before being
delivered to the induction pipe. In order to reduce the mixture
temperature to a normal figure, a box-like intercooler was interposed
between the outlet of the second-stage supercharger and
the rear of the cylinder blocks. In a typical Spitfire installation
the intercooler radiator was mounted under the port wing in a duct, which also housed one of the main engine-cooling radiators."

13. "The real significance of the Merlin 61 was that at 40,000ft it
developed double the power given at a much lower altitude by the
Merlin II of 1939/40. Even at 23,500ft its maximum power was
1,390 h.p. The weight had risen to 1,640 lb."

14. The 67 had a reduction gear of 0.42:1 instead of 0.477:1,
as had the 63, 64 and 66, and the 68 was a Packard-built model,
designated V-1650-3 and installed in the Mustang I I I . Its takeoff
output was 1,400 h.p.

15. "The 67 had a reduction gear of 0.42:1 instead of 0.477:1,
as had the 63, 64 and 66, installed in the Mustang I I I . Its takeoff
output was 1,400 h.p. In the Merlin 69—another Packardbuilt
variant, known in America as the V-1650-7—1,490 h.p. was
available for take-off; this engine powered Mustang I l l s and IVs."

16. "The Merlin 130 and 131 were the first of their family to incorporate
downdraught carburettors; and, to eliminate the air scoop
as used on the Mosquito, ducted air intakes were faired into the
leading edges of the wing. The war-time Bendix/Stromberg
carburettor was replaced by a low-pressure fuel-injection system,
which delivered through a spray nozzle into the supercharger eye*.

17. The sum total of improvements incorporated
in these remarkable engines raised the output to 2,030 h.p. at
1,250ft with a boost of plus 25 lb/sq in.

18. Feel free to add your own episode !

*Ivan are your sure of your doc ?

[Osprey]

I don't understand your point Tomcat. Are you seriously arguing the 87 octane case here? I expect it from Kurfurst because he appears to have painted himself into a corner with too much personal pride invested in the argument. But you claim to be a man of education by profession?

@klem, I am a mission builder for our server and it does and will run historical missions only. We have a Luftwaffe faction too, they won't have a problem with it.