Suggested, complete Spitfire lineup for Aces High

[mw]

Hello 1K3:

There is information on Spitfire I and +12 lbs boost here:

http://www.spitfireperformance.com/spit1vrs109e.html

Regards,

Mike

[Kev367th]

Of course which Spit 1 do we have?
Yup you guessed, the 6lbs boost one.

[Karnak]

1K3,

The immediately relevant section from mw's link:

The Merlin III data is from Rolls-Royce.  Trials were successfully carried out in October 1939 to increase the power of the Spitfire's Merlin II and III engines by raising the manifold pressure to +12 lbs./sq.in.   Emergency use of +12 lbs./sq.in boost was officially adopted 20 March 1940 with the release of the Air Ministry's Air Publication A.P.1590B/J.2-W.    It was also in March 1940 that the Spitfire squadrons switched over to 100 octane fuel, without which +12 lb boost would not have been possible; therefore no Me-109 E ever met a Spitfire that did not have 100 octane fuel in its tanks.    Combat reports show that +12 lb boost was used by the Spitfire squadrons during their first combats with the Me 109 E in May 1940 while covering the Dunkirk evacuation.

[Kev367th]

Proves 1 thing Karnak -

HT's total disdain for anything RAF.

We have a virtually unused (in combat) Spit 1 with 6lbs boost.
A really fugged up Spit 9
A very overpriced Spit XIV

And nothing between 1943 and 1944/5 thats free.

RAF must have the most fugged up planeset in the game.

[Kurfürst]

+12 lbs boost was by no way the standard and solely used boost in the Mk I. It would require 100 octane fuel, otherwise with 87 octane

Mike claims on his site that 'all and every' Sqns switched to it, but as with his previous claims about +25lbs XIVs, nothing except his own fanatism underlines a complete and immidiate changeover from 87 octane and that 'no spitfire ever met a 109 without 100 octane fuel in it`s tank'.  

He also foolishly assumes other things, and in contradiction with himself he claims tests of captured Spitfires in rechlin did not succeed because 'rechlin did not have 100 octane fuel', which is of course would be wrong even in 1939, in fact the rechlin papers themselves note the use of 100 octane fuel.

In short, it`s mere guess, important for the agenda of his spitfire uberness site.


However the British archives says not so. +12 boost was definietely used, but not in the amount MW would like it to be : shortage of 100 octane fuel prevented 100% coversion until November 1940.

The following is from a discussion from Butch`s board :


"The first bulk shipment of 100 octane fuel had arrived in Britain in June 1939 from the Esso refinery in Aruba. This and subsequent tanker shipments from Aruba, Curacao and the USA were stockpiled while the RAF continued to operate on 87 octane petrol. Having secured what were considered reasonably sufficient quantities of 100 octane, Fighter Command began converting its engines to this standard in March 1940, allowing boost (manifold) pressures to be raised without the risk of detonation in the cylinders. This initial increase in maximum boost from 6 lb to 9 lb delivered a useful power growth of around 130hp at the rated altitude.

By the time of the invasion of the Low Countries by Germany in May 1940 the RAF had converted approximately 25 % of it's total fighter force to 100 octane fuel use. The subsequent escalation in air activity and demands placed upon Fighter Command over the next two months put great strain on both the 100 octane fuel stockpiles and aircraft modified to use the fuel. Against the backdrop of total war the RAF found that it's reserves of 100 octane fuel was well below the level considered necessary for widespread use, for any sustained length of time.

Two actions were immediately undertaken by the British War Cabinet in May to resolve the looming crisis. Firstly 87 octane fuel was deemed the primary fuel source to be used until further supplies could be discovered and delivered in sufficient quantities to allow the Merlin conversions to again take place. Those existing fighters already so converted (approximately 125) would continue to use what supplies of 100 octane were available, but all other fighters that had not been modified to continue with the use of 87 octane (of which there was more than adequate supply). The second action was for the British Government to contract the Shell Oil Refining Company to assist the British-controlled Iraqi Petroleum Company at Kirkuk to produce 100 octane fuel. This arrangement proved quite successful as production was quickly converted to 100 octane fuel.

The first Middle East shipment of 100 octane fuel arrived in Portsmouth on 12th August, with a further two deliveries in September and four in October. Although too late to allow widespread conversion for the use of the fuel the deliveries did ensure that from this point on Britain would not be lacking in 100 octane fuel levels. With the newfound supply RAF Fighter Command again embarked upon a Merlin II and III conversion to 100 octane use from late September, finally achieving 100% conversion of it's fighter force by the end of November in 1940.

http://www.allaboutwarfare.com/forums/index.php?showtopic=230&hl=



I came across it when I was in fact researching another subject (Dutch East Indies Fuel levels prior to the Japanese Invasion) at the Australian War Memorial Archives.

It's from a document, copied to the Australian Military Commission in England in February 1941, by Roll Royce to Lord Beaverbrook outlining past, current and proposed changes to the Merlin; and factors that affect it's performance.

It was quite an interesting paper actually, even though i found it to be a very dry subject.


It was a collection of lose-leaf typed pages, included as an addendum in a report titled Fuel Supplies to The British Empire And It's Commonwealth; Outlook, Ramifications and Projections For The Prosecution Of The War.

The reason why it is included amongst AWM papers is because the Australian Government at that time was protesting vigoriously about the continued supply of lower grade 87 octane fuel when it too wanted 100 octane for the RAAF.

I believe that McFarland, Pugh, Hart, Perret, Lumsden and even Churchill have all quoted parts from the report.

[Angus]

Uhmm, from Izzy:
"+12 lbs boost was by no way the standard and solely used boost in the Mk I. It would require 100 octane fuel, otherwise with 87 octane

Mike claims on his site that 'all and every' Sqns switched to it, but as with his previous claims about +25lbs XIVs, nothing except his own fanatism underlines a complete and immidiate changeover from 87 octane and that 'no spitfire ever met a 109 without 100 octane fuel in it`s tank'. "

Okay, my .02$ on this.
12 lbs was the most common, but I belive the changeover didn't happen all at once. Izzy has a point there.
Another thing no less important was the changeover of the aircrews. the 3 blade rotol drastically changed ROC and acceleration, however not top speed.
At the end of BoB, most sqn's had +12 and a rotol.
I calculated the performance of some 87 oct Spitfires in climb to Nm's and the lift performance was some 10% above the 109E at the time, however I need more 109E's to get a better test, and I didn't come across the Spit I's 100 oct+rotol data either.
The Mk II also entered service in the BoB, - increased performance at high altitude.
Not all 109's were the newest model either, so you could basically expect many different things to line up.

I have seen somewhere 25 boost mentioned for the XIV, just can't figure where. Perhaps diver-hunters?  Anyway, I remember it being discarded in the Izzy way that XIV's never were shipped to the far east, - but those I found.
Our Spitfire Lineup sucks IMHO, the I is the worst, the V the best, the IX is a hybe and the XIV is overpriced as well as being a sloppy XIV (climb performance is under). Well, many above in this thread already said that....

[MiloMorai]

Now it does not break it down by month but that 22,500 bbls (787,500gal) per week is enough for 8949 Spitfire sorties per week.

Since some might be able to access the link:

by Neil

"2./ Notes of a meeting held in AMPDS room on the 16 March 1939, to consider the question of when 100 octane fuel should be brought into use in the RAF and of the number and type of squadrons to be supplied with the fuel.

16 fighter squadrons and 2 twin engine bomber squadrons by September 1940, annual consumption 10,000 tons. Brought forward to early 1940 by subsequent events.

4./ 11/7/40 RAF had 343,000 tons of 100 octane in store.

5./ 10/10/40 RAF had 424,000 tons of 100 octane in store. After 22,000 tons issued during the B of B."

That 343,000 tons in store in July 1940 is ~11,000,000 gals or enough for ~130,000 Spitfire sorties.

This seems to contradict the quote by Pips and as suggested by Neil could have been a deception  by the Brits upon the Aussies.

[Kurfürst]

Neil`s claims underline what pip`s document said. Neil claims 16 fighter squadrons, that`s about 1/4th of the RAF-FC strenght .

Furthermore, the 100 octane consumption was 6000t/week in the start of November. Pips doc underlines that by November, FC had 100% changed over to 100 octane.

During the battle, 10 July-10 Oct, 22 000 tons was issued....  22/6=ca.3.5 weeks, let`s be generous and say, enough for either

a, only a month  b] if everyone uses it.[/b]
b, 3-4 months if only 25-33% of the fighters are using it.

But of course 10 July-10 Oct was a 3 month period.

So, Pips document is underlined well. Moreover, it`s more believable that the transition took a few months than the NS/MW story about of a sudden, immidiate and 100% conversion as if touched with a magic wand...

it`s *interesting* though that while Neil and Mike have managed to find 100 octane consumption in the UK to support their cause, surprisingly, they never found or presented any paper on 87 octane consumption...

Even if that would clear up totally how much 100 octane was used in 1940 compared to 87 octane.

Perhaps that`s the reason why it`s never shown.

[MiloMorai]

Naturally you only see and read what you want to be true Kurfy.

Here it is again:

"2./ Notes of a meeting held in AMPDS room on the 16 March 1939, to consider the question of when 100 octane fuel should be brought into use in the RAF and of the number and type of squadrons to be supplied with the fuel.

16 fighter squadrons and 2 twin engine bomber squadrons by September 1940, annual consumption 10,000 tons.
Brought forward to early 1940 by subsequent events"

Notice the bold. It does not say there was only 16 fighter squadrons in Sept. In Aug 1940 there was 19 squadrons of Spitfires so even though you comprehension is faulty that is only 3 less.
 
Now your 22,000 tons is 6,900,00 gals or enough for 78,750 Spit sorties or 6562 Spit sorties per week or 937 Spit sorties per day for that 3 months when the LW got its butt kicked.

Squadrons using 100 would be in 11 Group, were it was needed the most. Other Groups would be using 87. In Aug, 11 Group had 6 squadrons of Spits and 15 squadrons of Hurries. That is 33% of all Spit squadrons at the time.

There was not shortage of 100 fuel. The shortage would be in the parts required for the engine to use 100 fuel.

"4./ 11/7/40 RAF had 343,000 tons of 100 octane in store.

5./ 10/10/40 RAF had 424,000 tons of 100 octane in store. After 22,000 tons issued during the B of B."




You have not yet provided any docs on C3 production/consumption for 1945 either.

[Karnak]

Originally posted by Kev367th
Proves 1 thing Karnak -

HT's total disdain for anything RAF.

We have a virtually unused (in combat) Spit 1 with 6lbs boost.
A really fugged up Spit 9
A very overpriced Spit XIV

And nothing between 1943 and 1944/5 thats free.

RAF must have the most fugged up planeset in the game.

I disagree.  I think that they went with the data they had on hand and it just happens that it is what we got.

[Crumpp]

Considering that the only difference between the 2, was the engine mounted cannon, it does not matter which variant is being tested as both would have simular stats.

Your absolutely correct Milo.

It speaks volumes that the RAE did not have a proper identification on the varient of 109 they were testing.  It is a glaring and obvious difference.  It would be very hard to miss as soon as the magazines were opened.

All the best,

Crumpp

[Angus]

Did the Hurricanes not go to 100 octs as well?
I remember some anecdotes of Hurricanes outclimbing Spitfires when forming up to intercept a raid. That could also be an airscrew issue perhaps?

Anyway, off to bed. Cya

[Squire]

100 octane was standard for all RAF fighters in the BoB. Hurricane, Spitfire, Defiant et all.

The BEF fighters used 87 octane in France.

[Angus]

So, has the jury reached a verdict?

Spit I, 100 oct
Spit V, 12 boost
Spit IX LF +25, clipped. Merlin 66
Spit VIII, + 25. Merlin 70.
Spit XIV with at least normal ROC.

Some seafire modifications....

uhm, did I forget some?

[Karnak]

Originally posted by Angus
So, has the jury reached a verdict?

Spit I, 100 oct
Spit V, 12 boost
Spit IX LF +25, clipped. Merlin 66
Spit VIII, + 25. Merlin 70.
Spit XIV with at least normal ROC.

Some seafire modifications....

uhm, did I forget some?

Yes, you left out the 1942 Spitfire and made the LF.Mk VIII redundant.


The list:

Spitfire Mk Ia, Merlin III at +12lbs boost for 1940.

Spitfire LF.Mk Vb, Merlin 45M at +12lbs boost for 1941 to mid 1942.

Spitfire F.Mk IXc, Merlin 61 at +15lbs boost for mid 1942 to mid 1943.

Spitfire LF.Mk VIIIc, full span wings, Merlin 66 at +18lbs boost for early 1943 to mid or late 1944, also useful for a wide variety of theaters.

Spitfire F.Mk XIV, full span wings, Griffon 65 at +21lbs boost for the ultimate perked Spitfire 1944 to the end of the war.

Spitfire LF.Mk XVIe, clipped wings, Merlin 266 at +25lbs boost for mid 1944 to the end of the war.

Seafire L.Mk III, Merlin 55M as the most common Seafire.