Virtual Museum
Click photos to enlarge image of a bat [The Bat Missile]
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The Missile (Room 2)

The Bat was a glide bomb carried by a Navy PB4Y-2 Privateer patrol bomber or other aircraft and was designed to destroy ships and offshore enemy targets.[Line drawing depicting the inner workings of a Bat Missile]Visual contact with the target was not required.

Launching Characteristics:

  • Launching altitude: 15,000 to 25,000
  • Launching speed: 140-210 knots
  • Range: 15 to 20 miles from its target
  • Payload: a 1,000 pound general purpose bomb warhead.

Steering Mechanism

The Bat was steered by controllable wing-mounted elevons driven by autopilot servomotors linked to the radar guidance system. The missile had fixed tail surfaces and was gyro-stabilized.

Dimensions

  • Length: 11 feet 11 inches
  • Span: 10 feet
  • Empty weight: 600 pounds
  • Loaded weight: 1,600 pounds.

Why a Bat?

When hunting or traveling in environments where visibility is poor, several species emit sound waves, then use their auditory systems to interpret reflected waves from prey or objects in their travel path. This ability is termed echolocation. By emitting a series of ultrasounds that either sweep from a high to low frequency or vary around a frequency, bats can distinguish, locate, and target prey.

The same idea applies to the Bat Missile. By transmitting radio waves, then interpreting the reflected waves with its radar receiver, the weapon guides itself to the target, even if the target moves after launch.

The Guided Missile Program: Bat Precursors

[Standing in front of the bat missile are several scientists and military officers instrumental in its development]

The National Defense Research Committee initiated the U.S. guided missile program in 1940. The goal of the program was to develop a winged bomb with the ability to automatically seek out and strike its [A Navy airplane launches a Bat test missile] target. In 1942, after a prototype design by the Radio Corporation of America (RCA) ran into complications, the NDRC asked the Bureau to aid in the aerodynamic and servomechanism (control) development of the weapon.

To head the operation, NDRC turned to Hugh L. Dryden, Chief of NBS' Mechanics and[Dr. Hugh L. Dryden, NDRC consultant] Sound Division and NDRC Consultant. Tests began in 1942 under the code name "Robin." A ground operator using a remote control and a television receiver guided these first models. Yet due to electrical interference, noise, and vibrations, the tests did not meet the project goals. The servomechanism repeatedly failed.

Members of the Naval Bureau of Ordinance observed these first model tests. Their interests, however, fell in the realm of radar homing technology for guided missiles. The naval officers observing the tests convinced members of Dryden's unit to explore radar-guided glider systems as well as continue the television-related work.

Radar research quickly advanced farther than the television research did. Dryden's division at the Bureau expanded to more than 100 members to accommodate the workload.

The NBS-led team developed two radar missiles. The servomechanism for the first type of missile, named "The Pelican," included only a radio receiver. The plane carrying the weapon would identify a target by sending radio waves at it. The missile's receiver would home in on the reflected radio frequency emitted by the target. Zenith provided the receivers, the Vidal Research Corp. provided the glider frames and final assembly occurred at the Bureau. The first flight demonstrating homing control took place in December 1942. (At one point, the OSRD considered using famous psychologist B.F. Skinner's positive reinforcement conditioning of pigeons to steer the pelican.)

Again, test results were not favorable. In the haste to prepare the weapon, certain instrumentation difficulties were accepted. This led to serious production flaws and subsequent failed test flights.

The Final Product

[The radio receiver inside the body of The Pelican]

While the flaws in "The Pelican" were corrected with ease, the minor setback opened the door for the second type of radar-guided missile: The Bat. Bell Telephone Laboratories and Massachusetts Institute of[The Pelican Missile] Technology collaborated to build its guidance systems while groups under NBS scientists Hunter Boyd and Harold Skramstad developed the Bat's aerodynamic and stabilization characteristics.

Armed with dummy bombs, Bat Missile flight tests started in May 1944. A few months later, comparative tests between the Pelican [Bat test missile poised to strike an abandoned barge] and the Bat at the Naval Air Ordnance Test Station at Chincoteague Island, VA, proved that both were ready for combat.

Although both versions passed the test, only the Bat went overseas. It eventually saw combat service in 1945, and destroyed several Japanese ships off the coast of Borneo including a destroyer. Several Bat Missiles were also fitted with modified radar systems and destroyed Japanese-held bridges in Burma and other areas. Thousands of Bat missiles were produced and went through several modifications. next>>



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date created: May 21, 2001
date revised: October 18, 2004