NOTE: Based on combat experiences, continuous changes are being made in
the oxygen systems and oxygen supply in heavy bombers. The following
considerations apply only to the type of ship specified. Newer models
and ships modified at staging areas may be different both in arrangement
and number of oxygen cylinders. KNOW the oxygen supply for YOUR STATION
IN YOUR SHIP.
Two types are found in the B-17. EIGHTEEN G-1 cylinders contain the
main supply which is distributed through the four systems. All are
filled through a single recharging line.
The G-1 cylinder has a volume of 2100 cubic inches and contains 30
cubic feet of oxygen when charged to a pressure of 450 pounds per square
inch. In combat the cylinders are charged to 450 pounds or better (all
cylinders have been tested to withstand 700 pounds pressure). Each
cylinder is check-valved so that one of a bank of cylinders may be shot
out with loss of no oxygen from the remaining intact cylinders. Between
20,000 and 30,000 feet, one G-1 cylinder charged to 450 pounds will last
one man approximately 5 hours (Auto-Mix "on").