5 Things You Didn’t Know About The B-17’s Infamous Ball Turret

The B-17’s ball turret was famous for its iconic design and its claustrophobic firing position. It was one of the most vulnerable positions on the B-17, designed to provide defensive firepower against enemies attacking from below. Here are 5 things you should know about this controversial gunner turret:

1. The turret had to be elevated to avoid hitting the ground during takeoffs or landings

It was strictly forbidden for the gunner to be inside the turret for either takeoff or landing.

The guns protruded 36 inches from the turret, more than the ground clearance, so it had to be elevated to the maximum 85 degrees from the vertical.

When the B-17 reached 9,000 ft and up, the gunner would then be able to enter the turret.

2. Operators of the ball turret had to go inside mid-flight

To enter mid-flight, the gunner first releases the handbrake next to the hand crank on the turret ring trunnion assembly.

He then releases the elevation clutch control, allowing the hand crank to move the turret. The gunner then cranks the turret into a vertical position so the guns pointed straight down, fully exposing the entry hatch.

3. They had to use a pulley system to cock the guns

Since it was easy to brush the gun firing buttons on top of the hand grips, the gun selector switches were always left to the OFF position until they went into combat.

This meant the gunner needed to charge the two machine guns in the air. This operation is usually straightforward, but the slide assemblies were near the ears of the gunner, making it harder to pull the cocking handle from that angle.

To circumvent this, two cables were attached to the slide assemble and they ran via two sets of pulleys to two handles near the gunners feet.

To cock the guns, he would lean forward, grasp the handles cross-armed, and pull them towards him.

4. Contrary to popular belief, gunners were actually protected by several defensive countermeasures

The gunner’s seat was made of 0.6-in thick steel while the curved bottom panel was made from 0.26-in thick steel. The hatch, which was behind the gunner’s head, was cast of thick aluminum 0.26 in thick.

The armor plates were design to give protection against rounds of up to 30 caliber, and would also help by deflecting Flak fragments.

In addition, the position of the guns, ammo boxes, and gun sight gave the gunner protection for the areas not covered by armor plates.

5. The turret could be jettisoned during crash landings

Before the hatch could fully open, the turret had to be rotated so that the guns faced straight down. If power was lost, it could be turned with two hand cranks.

In extreme cases, the turret could be jettisoned if it was going to crash land.

To do it, the 12 connecting nuts holding the 4 harness legs had to be removed. Then, the 4 safety retaining hooks also had to be removed allowing the turret to drop away. These could be achieved by using a wrench or smashing the hooks with a hammer.

This whole procedure can take up to only 20 minutes.