 Modifications to the bomb bays were extensive and time @-@ consuming . Its four 12 @-@ foot ( 3 @.@ 7 m ) bomb bay doors and the fuselage section between the bays were removed and a single 33 @-@ foot ( 10 m ) bomb bay configured . The length of the gun @-@ type shape was approximately 17 feet ( 5 @.@ 2 m ) . New bomb suspensions and bracing were attached for both shape types , with the gun @-@ type suspension anchored in the aft bomb bay ( although its length protruded into the forward bay ) and the implosion type mounted in the forward bay . Separate twin @-@ release mechanisms were mounted in each bay , using modified glider tow @-@ cable attach @-@ and @-@ release mechanisms . 
