[OBXWanderer]

Each crew station has its escape hatch and ejection seat

Back when the BUFF's had tail gunners, I am thinking D models and earlier, the tail gunner went out one of the lower escape hatchs. He was taught to immediately "ball up". Once he counted three bumps, he was clear of the aircraft.

[cmdr straker]

A thru F models had actual Tail gunners. G’ and H models had gunners up front.

[BatGuano]

I'm probably late with this post but the tail gunner's escape on those early model B-52s was to jettison the turret and step out of the airplane. (he flew strapped in a chute, of course) To use the lower ejection seat hatch the gunner would have to crawl about 140 feet through the unpressurized bomb bay. The open hatches were used by extra crewmembers, usually instructors or evaluators, that did not have ejection seats.

[pfflier]

The gunners were in the rear of the B 52 until the G and H models. They didn't eject. They released the gun turret from the aircraft and jumped out of the hole. Not good for survivability at low altitude. That's where the three bumps come in. It is a sarcastic reference to rolling down the runway behind the aircraft.

The H models no longer have a gunner.