The systems differ radically from those of the B-17. In models up
through H to early J each individual draws from at least two or three
cylinders. With the exception of the nose positions there is a maximum
of two men on the same system. As shown in the diagramatic sketch (page
47B), the pilot, co-pilot, side gunners, and tail gunner each have their
own individual system of at least two G-1 bottles.
In the G, H and early J series the three regulators in the nose are
supplied by a single system containing only three oxygen cylinders.
(diagram page 47B). This is inadequate. The later J models have a
modified system to the nose wherein the bomb bay - radio operator system
is Tee'd into the supply to the nose positions. This brings to a total of
six oxygen cylinders for the five stations. (diagram page 47A). Since
the regulators at the radio operator and bomb bay stations are not used
continuously during combat missions, this modification to the nose
positions is adequate. Further, the connections in the lines leading to
the nose are such that the nose positions are supplied individually as
well as collectively so that loss of the supply to one system does not
necessarily deplete the other systems. KNOW THE OXYGEN SYSTEM IN YOUR
SHIP.
The bottom turret and camera tunnel regulators are supplied by the
same system containing three cylinders.