Another, and somewhat closer-up, image of the SWOD Mark 9. It has been described as one of the world’s earliest fully-automatic, target-seeking “smart” weapon systems, and saw limited use against Japanese targets in 1945. The radar used is now considered primitive, and it was relatively easily confused by radar returns from objects other than the intended target. At minimum, however, it is credited with successfully sinking some Japanese ships.

US Navy SWOD Mk 9

Reconnaissance seaplane Vought OS2U-3 Kingfisher, piloted by Lt. Fred Hunter, takes off from a catapult on USS Detroit CL-8, Omaha-class light cruiser,  in the Aleutian Islands.

Launching seaplane

The Bat used a S-band active radar seeker developed by Bell Telephone Laboratories, and a 1,000 lb warhead with an impact fuse. The 1,700 lb weapon was released at medium to low altitudes and would home on its target once the seeker was activated. The primary delivery platform was the Convair PB4Y-2B Privateer, a single tail stretched derivative of the B-24 series. Each Privateer carried one Bat under each wing. It's internal radar painted its target and its radar-receiver picked up the echoes from its target. 