B-17’s carried two waist gunners; each protected his respective side of the aircraft. Early waist gunner positions were directly across from each other, often causing the gunners to bump into one another and getting entangled in each other’s oxygen lines. Later, the positions were staggered, giving the gunners greater mobility.
On early B-17’s, waist window coverings were on slide rails and had to be opened before combat so the guns could be swung out from their stowed positions. Improvements introduced on the B-17G mounted the guns to the inner frame of the windows and were enclosed with a permanent Plexiglas covering, which meant the gunners didn’t have to stand in the freezing slipstream, as in earlier models.