pop corn tubes for in flight movie goers
Kind of an interesting way of controlling altitude plus ascending and descending. Also it would be a delicate balance between slightly compressing the helium by reducing its free volume with the air in the ballonets the air would also become denser under a slightly higher pressure making it negatively buoyant
Ralph, I can see 2 wires on the upper leading edge of the angled tube, and on the "circumferential band" just back from the opening I can see wires running down to the stays running aft from the cockpit, plus there looks to be others also running from that band up to the hydrogen envelope.
Page 22 describes the "Envelope Pressure Control System" and the functions of the fore and aft ballonets.
The previous section contains a detailed tally of the weight of the components in the airship including the machine gun and ammo.
(I don't think that I'd like the job manning the machine gun.)
Fullsize image: https://s3-us-west-1.amazonaws.com/h...s_fullsize.jpgShip fitters, Mare Island Naval Shipyard, California, circa 1943.