Return to Table of Contents

3.   Specifications and Supply of Jet Fuels

The requirements for jet fuels in Germany were increasing rapidly at the end of the war. The 1944 consumption was 650 barrels per day and it was planning to increase that figure to 3,250 barrels per day in 1945. While the consumption apparently never was reached, the demands had become appreciable in terms of Germany’s available supply of liquid fuels.

Mixtures of gasoline and diesel oil fractions were used as fuel in 1944, but with increasing requirements efforts were being made to use highest boiling fractions only in order to release all gasoline for other critical uses. Tests were in progress using materials from the sump phase and pre-hydrogenation steps in coal hydrogenation. The tests had shown that only a low aromatic content could be tolerated if clean burning was to be obtained, and it was also concluded that some gasoline was necessary in order to obtain satisfactory ignition.

The status toward the end of the war was that gasoline-rich mixtures were still being used with the higher boiling diluents being any available material such tat the blend not the following specifications.

  1. Viscosity maximum 12 centistokes at -31 degrees Fahrenheit (or maximum 22 centistokes at -4 degrees Fahrenheit). The viscosity specification was to insure flow through the fuel pump and good distribution in the fuel jets.
  2. Pour point maximum -31 degrees Fahrenheit. (It was stated in another instance that in practice the maximum pour point was -40 degrees Fahrenheit and that no crystal appearance could occur above -13 degrees Fahrenheit). In a flight of one (1) to one and one-half (1˝) hours, such as is experienced with jet fighters, the contents of the fuel tank can reach a temperature low as -31 degree Fahrenheit. For long distance flights it was believed that the pour point specification would have to be lowered to -56 degrees Fahrenheit.
  3. The fuel shall burn without carbon formation. aromatic oils deposit carbon in the combustion chamber and the turbine. Paraffinic oils are clean burning and therefore desired for fat fuels. It was the opinion in Germany that the chemical character (and hence burning quality) of the fuel was of more importance than such properties as boiling range.
  4. Heating value minimum 16,000 BTU per pound.
  5. Sulfur content maximum 1.0 percent weight.

Return to Table of Contents