One feature I loved about AW was the porking of an airfield's fuel tanks or destroying the enemies refineries thereby limiting a certain plane's performances and thier availablity from airfields.
Seems destroying refineries and fuel tanks lowered the octane value of the fuel, tho german planes didn't need the higher octane value, the British planes did.
This is historically accurate as a matter of fact, and a feature I'd like to see implemented.
To support my case I post this re-print;
FUEL FOR THE FEW
The Battle of Britain's narrow margin might just have been owed to the secret new
100-octane fuel which had been developed by British and American oil experts.
Sir Peter Masefield adds a significant new appendix to the history of the Battle.
One of the least recorded but most significant contributions to the performance of the Hurricane and Spitfire during the Battle of Britain was the introduction of a special 100-octane fuel for their Rolls-Royce Merlin engines.
That advance in fuel technology, which came into service with RAF Fighter Command from
March 1940, made possible the rich mixture use of up to 12-lb. boost (54 in mercury
manifold pressure), at 3,000 rpm in Merlin engines without encountering detonation.
The result, compared with the former limit of 6.25-lb. boost (41.5 in Hg) with 87-octane
fuel, was an increase of some 300 bhp-a "gift" which substantially improved both the rate of climb and the maximum speeds of the Hurricane and Spitfire.
The story has so far never been told in detail-nor with accuracy. It has, however, now been chronicled by my old friend Alexander Ogston, formerly technical supervisor of International Aviation Associates-a London-based unit of the Standard Oil Company, New Jersey, then Esso and now Exxon Alec Ogston, with Dr. William J. Sweeney of the Standard Oil Development Company and W.W.(Chic)White of International Aviation Associates, did much to instigate research to produce the special aromatic 100-octane fuel to achieve the
"rich-mixture response" from the Merlin and other British aero engines.
Earlier 100-octane fuel developed for the United States Army Air Corps in 1937 had no
such qualities because the aromatic content was less than two percent.
To achieve the required rich-mixture response from British Rolls-Royce Merlin and Bristol radial engines, the aromatic content had to be close to 20 percent.
Alex Ogston recalls that the fuel used by the Royal Air Force in the 1920s was termed
"80-20," a blend of 80 percent aviation spirit (i.e., petrol or gasoline) and 20 percent benzol (i.e., aromatics). Thus, unlike American engines, British engines had been "brought up and educated" on aromatic fuel.
Though all mention of 100-octane fuel was classified as secret when the war began, in
fact The Aeroplane had carried an article about it on 29 March 1939 (page 426).
The Germans, apparently, did not realize its significance.
As Alec Ogston relates, in 1938 the Air Ministry placed a contract with the AngloAmerican Oil Company (now Esso Petrolet, Company) for single-cylinder and full-scale engine tests of some relatively small initial shipments of Esso 100-octane fuel to the United Kingdom.
These tests were conducted for Rolls Royce largely by Dick Mallinson (on the staff of Cyril Lovesey) and for the Bristol Engine Company by Harvey Mansell. Both worked in
conjunction with Dr. John Drinkwater of RAE Farnborough and with Alec Ogston from the
oil company.
They showed that the cause of the lack of rich-mixture response in the American fuels
was their low aromatic content. They were, in fact, a blend of 100-octane (2-2-4 trimethyl pentane, produced by the alkylation process) with a paraffinic gasoline of less than two percent aromatic content.
This was designed specifically to meet the
requirement of the United States Army Air Corps and to avoid the solvent effect of
aromatics on United States aircraft fuel systems.
For the British engines and fuel systems the answer was to replace the paraffinic
gasoline component with a highly aromatic gasoline distilled from Venezuelan Quiri-quiri crude.
A first cargo of this "improved" 100octane fuel was shipped to the United Kingdom from
Aruba in the Netherlands West Indies in June 1939, on board the tanker Beaconbill.
A portion of it was set aside to act as a "reference fuel" -later code-named RDE/F/222.
Subsequently, in 1939 and 1940, some 70 percent of the 100-octane fuel stockpiled by
the Air Ministry for Royal Air Force Fighter Command-and used throughout the Battle of
Britain-was supplied from three Esso refineries, two in the USA and one in the Caribbean, where the alkylation process was used to manufacture the iso-octane components of the 100-octane blend.
The process had been discovered in 1935 by Dr. S.F. Birch, of the Anglo-Iranian Oil Company (now BP). Thereafter, Esso pioneered its commercial use. Most of the remaining 30 percent of the UK supplies came from Shell, with a small quantity from the Trinidad refinery of Trinidad Leaseholds.
In addition to the innovators from Esso, Rolls-Royce, Bristol and the RAE, those who were most closely involved in this major endeavor of so much importance in the Battle of Britain included that great "fuel maestro," F.R. Rod Banks of the Ethyl Corporation, with Ernest Bass and Maxwell Smith of Shell.
As a matter of record, the Shell 100 octane was originally made up of a blend of a highly
aromatic gasoline from Borneo crude, blended with mixed octanes produced by a hydrogenation process together with 3.66 CM3 of tetraethyl lead per gallon.
On 6 July 1939 Dick Reynnell of Hawker Aircraft flew an early production Hurricane
(L ' 1856) in which the Merlin engine was run on 100-octane fuel.
There can be no doubt that from March 1940 onwards the use of the distinctly green
colored, 100-octane fuel by RAF Fighter Command (compared with the previous
blue-colored 87 octane) imparted a most effective additional boost to the performance of the Hurricane and the Spitfire flying against the Messerschmitt Bf- 109 fighters.
Their direct-injection Daimler Benz 601A engines operated on 87-octane fuel with no
rich-mixture response.
The increased rate of climb and maximum speed imparted to the Hurricane and Spitfire
by 100-octane fuel was, of course, limited to the heights at which the supercharger made
possible the attainment of better than 61/4 -lb. boost.
For the Merlin II and III in the Spitfires, Hurricanes and Defiant of the Battle of Britain this meant extra performance up
to the rated height of 12,250 feet in standard atmosphere.
The contribution of the 100-octane backroom boys to the Battle of Britain must go down
in history alongside the aircraft, engines and radar as a valuable contribution to victory.
-Reprinted trom Aerospace Magazine-October 1990
[ 09-07-2001: Message edited by: milnko ]
