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

[41Sqn_Banks]

Originally Posted by Crumpp

Where does it clearly say that?

"it is emphasized that the high boost for emergency may only be employed with 100 octane fuel"

It does not, the General Operating Notes clearly say he can use it.

http://forum.1cpublishing.eu/attachm...8&d=1337207418

"Clearly say ..." we obviously have a different understanding what clearly means.

That's what I call clearly:
January 1939: http://forum.1cpublishing.eu/attachm...0&d=1334682385
"100 octane must be used"

March 1940: http://www.spitfireperformance.com/ap1590b.jpg
"100 octane must be used"

April 1940: http://www.wwiiaircraftperformance.o...erlin3-pg6.jpg
"100 octane ... must be used"

November 1940: http://forum.1cpublishing.eu/attachm...5&d=1337196053
"only be employed with 100 octane fuel"

June 1941: http://forum.1cpublishing.eu/attachm...0&d=1334727256
http://forum.1cpublishing.eu/attachm...1&d=1334727263
"only of 100 octane fuel is in the tanks"

[NZtyphoon]

Originally Posted by Kurfürst

Well let's see now the reality.

Tanker losses to all causes, I have gathered a total of 78(!!) tankers were sunk by mine, U-boot (typically), aircraft and raiders, between September 1939 and November 1940. About 90% of them were British, though there are a couple of Swedish, Dutch, French etc. tankers

I have them by name, date, cause of loss, route, cargo, tonnage and so on. For example indeed one tanker that went through Halifax, Inverdagle (9456 tons) was sunk by mines laid by the submarine U 34, with 12 500 tons of avgas - about a month worth consumption of 100 octane, though I am not sure what grade it actually carried - on the 16 January 1940....

Alltogether 558,260 GRT of tankers went to Davy Jones locker, by the end of November 1940, along with 385,957 tons of oil product. Half of that, ca. 243 000 GRT worth of tankers were sunk by the end May 1940.

Fuel oil was the greatest loss, 116 000 tons of it went down with tankers (luckily, no green peace back then). Avgas seems quite untypical as a load, but in the end it didn't really matter, because if a tanker sunk with diesel oil, or even empty, the next one had to haul about its cargo again.

Tanker losses were serious, unfortunately.

33rd Weekly Report Oil Position 23 April 1940 showing out of 242 Norwegian tankers 119 had been bought under Allied control, with 18 heading to Allied ports and the other 93 in neutral ports, or heading into neutral ports, the 119 brought under Allied control more than making up for the total tanker loss for the entire war period September 1939 to November 1940:

Originally Posted by Kurfürst

So disprove the statement of Pips. Since you misrepresent his position, I put it forward to you in its originality:

This is from a researcher, researching another subject (Dutch East Indies Fuel levels prior to the Japanese Invasion) at the Australian War Memorial Archives, 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 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. McFarland, Pugh, Hart, Perret, Lumsden and even Churchill have all quoted parts from the report.

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.

"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"

1st Monthly Oil Position Report July 1940 ( Dated 6 August 1940)



Table from 1st Monthly Oil Report July 1940: Consumption: Read in conjunction with attachment 1:


Table from 1st Monthly Report July 1940; Stocks dropped by 15,000 tons April-May then increased by 12,000 tons to June:


Table from 33rd Weekly Oil Position Report 23 April 1940 showing 100 Octane fuel being stockpiled in the UK and overseas; "West of Suez" - France springs to mind.




Oil Position 5th Monthly Report November 1940:

[Crumpp]

Could that be that when the pilots 'pulled the plug' the boost was still at a level before detonation occurs.

Absolutely. They could have easily "pulled the plug" to achieve any boost they desired once the override was on.

"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"

Why don't they just say "all aircraft" instead of specifying just modified ones? All aircraft should be modified, right??

Table from 33rd Weekly Oil Position Report 23 April 1940 showing 100 Octane fuel being stockpiled overseas "West of Suez" - France springs to mind.

What is the asterisk note and the bottom about? Can you show the whole document?

The last time you started talking about stockpiles in France, it was in reference to a report projecting fuel stocks for future war.

Now your saying West of the Suez means France? Heck, it could mean Cleveland Ohio or maybe Hornchurch, too?

Considering that they were shipping troops to begin the Desert War I would imagine that is a future projection of their needs for aviation fuel. The first British troops went on the offensive on 11 June 1940 in North Africa.

[Crumpp]

"Clearly say ..." we obviously have a different understanding what clearly means.

It is right there, you highlighted it. The RAE opened the can of worms and gave their pilots license to violate the airworthiness of the aircraft:

Camber says:
There would be nothing to stop a pilot pulling the boost override and adjusting his throttle handle

Exactly. We also see two things the give insight into the state of mind of Fighter Command.

1. First from the fuel committee meetings the confusion on exactly what must be done to modify the engine. I don't know if you have taken Organizational Behavior in college but if there is confusion at the top of any organization, there is even more confusion at the bottom of it. Even with a clear vision at the top, it is a process to get that vision communicated and enacted at the bottom. The larger the organization, the longer the lag time and more difficult the process.

Secondly, we see Dowding's memo warning the pilots about the dangers of overboosting. You can bet Dowding did not sit around wondering what to do that day and just decided to fill his time writing a memo about overboosting destroying engines. "Squeaky wheel gets the grease", that memo came about because his maintenance and logistics people complained if it does not change there could be consequences that effect their ability to keep his planes flying.

That memo was printed because they felt was a problem with pilots "pulling the plug" before they properly balanced the risk.

[NZtyphoon]

Originally Posted by Crumpp

Why don't they just say "all aircraft" instead of specifying just modified ones? All aircraft should be modified, right??

This is one of the amazing inconsistencies about the Pips memo - according to this

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.

a mere 25% of the fighter force - supposedly 125 fighters - caused such a high strain on 100 octane fuel supplies that all further conversions were stopped and the RAF ordered that 87 Octane fuel be the primary fuel.

Question is if 125 fighters can put a huge strain on reserves of 263,000 tons of 100 Octane fuel (as of 18 April - see Table 33rd Weekly Oil Report) , what kind of a strain are the other 475 fighters, plus all the other aircraft using 87 Octane going to put on the reserves of 327,000 tons of "Other grades" of fuel? This hasn't to my knowledge been commented on before, but it is patently ridiculous to state that 125 fighters put any kind of a strain on 263,000 tons of 100 Octane: then, on top of that, to insist the RAF decided to put even greater strain on the "Other Grades" stockpile beggers belief.

Originally Posted by Crumpp

What is the asterisk note and the bottom about? Can you show the whole document?

Take a look at the extreme RH side of table i (b) Weeks' supplys showing how long it was estimated the current stocks would last based on average consumption, and assuming no more supplies were shipped in.

This is the rest of the document:

Originally Posted by Crumpp

The last time you started talking about stockpiles in France, it was in reference to a report projecting fuel stocks for future war.

Nonsense, the documents showed quite clearly how much fuel was already in France (attached) and other papers in the series showed the projected requirements.

Originally Posted by Crumpp

Now your saying West of the Suez means France? Heck, it could mean Cleveland Ohio or maybe Hornchurch, too?

Yeah right, use a bit of common sense because in April 1940 the Italians had yet to declare war, so the Mediterranean and Africa were not war theatres, nor were there any aircraft using 100 octane fuel based in those areas and, contrary to your unproven speculation, fighters based in France were using 100 octane fuel, while some Hurricanes had been active in Norway. Not forgetting the Blenheim IVs of 2 Group and the BEF.

Originally Posted by Crumpp

Considering that they were shipping troops to begin the Desert War I would imagine that is a future projection of their needs for aviation fuel. The first British troops went on the offensive on 11 June 1940 in North Africa.

This is just pure speculation on your part - there is absolutely nothing in the paper talking about "future needs, projections" or any other such language.

[Seadog]

Note: these examples are all from May 1940.

Here's an example of 12lb boost at low altitude:



here's another:

http://www.wwiiaircraftperformance.o...e/bushell.html

note here that the pilot is using "full" 12lb boost and he has noted that he was at 5000-6000ft.

and another:

http://www.wwiiaircraftperformance.o...e/bushell.html

again at 5 -6000ft and again with 'full' 12lb boost

The idea that that they were using 12lb boost with 87 octane fuel could only be conceived by someone who desperately wants to avoid the truth.

[Kurfürst]

[Seadog]

[QUOTE=Kurfürst;427304]

and your point is?

[Crumpp]

Nonsense, the documents showed quite clearly how much fuel was already in France (attached) and other papers in the series showed the projected requirements.

Your document says absolutely nothing about fuel "in" France. It talks about requirements and estabilishments.

[Glider]

Present Establishment is what they currently are authorised to have plus they need an additional 200,000 gallons. In the same way the additional guards are an extra establishment. The current guards would be described as the present establishment

If we follow your logic then the RAF in France had no fuel of any description because you are turning all the current fuel (present establishment) into future requirements.