The ASM-N-2 Bat was a

United States Navy The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage ...

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great power ...

glide bomb A glide bomb or stand-off bomb is a standoff weapon with flight control surfaces to give it a flatter, gliding flight path than that of a conventional bomb without such surfaces. This allows it to be released at a distance from the target r ...

which was used in combat beginning in April 1944. It was developed and overseen by a unit within the

National Bureau of Standards The National Institute of Standards and Technology (NIST) is an agency of the United States Department of Commerce whose mission is to promote American innovation and industrial competitiveness. NIST's activities are organized into physical sci ...

(which unit later became a part of the

Army Research Laboratory The U.S. Army Combat Capabilities Development Command Army Research Laboratory (DEVCOM ARL) is the U.S. Army's foundational research laboratory. ARL is headquartered at the Adelphi Laboratory Center (ALC) in Adelphi, Maryland. Its largest sing ...

) with assistance from the Navy's

Bureau of Ordnance The Bureau of Ordnance (BuOrd) was a United States Navy organization, which was responsible for the procurement, storage, and deployment of all naval weapons, between the years 1862 and 1959. History Congress established the Bureau in the Depart ...

, the Massachusetts Institute of Technology, and Bell Telephone Laboratories. It is considered to be the first fully automated

guided missile In military terminology, a missile is a guided airborne ranged weapon capable of self-propelled flight usually by a jet engine or rocket motor. Missiles are thus also called guided missiles or guided rockets (when a previously unguided rocket ...

used in combat.

Background

In January 1941

RCA The RCA Corporation was a major American electronics company, which was founded as the Radio Corporation of America in 1919. It was initially a patent pool, patent trust owned by General Electric (GE), Westinghouse Electric Corporation, Westin ...

proposed a new TV-guided anti-shipping weapon, called Dragon, for which an operator would use the TV image sent from the nose of the weapon and operate aerodynamic controls during the weapon's fall. The

(NBS) would provide the airframe for use with a standard

bomb A bomb is an explosive weapon that uses the exothermic reaction of an explosive material to provide an extremely sudden and violent release of energy. Detonations inflict damage principally through ground- and atmosphere-transmitted mechan ...

, and was the same guidable ordnance airframe design used for the earlier, abortive

Project Pigeon During World War II, Project Pigeon (later Project Orcon, for "organic control") was American behaviorist B. F. Skinner's attempt to develop a pigeon-controlled guided bomb. Overview The testbed was the same National Bureau of Standards- ...

weapons program. The

Pelican Pelicans (genus ''Pelecanus'') are a genus of large water birds that make up the family Pelecanidae. They are characterized by a long beak and a large throat pouch used for catching prey and draining water from the scooped-up contents before ...

was a June 1942 modification using

semi-active radar homing Semi-active radar homing (SARH) is a common type of missile guidance system, perhaps the most common type for longer-range air-to-air and surface-to-air missile systems. The name refers to the fact that the missile itself is only a passive det ...

. By mid-1943, a modification of the design was proposed to use a new

active radar homing Active radar homing (ARH) is a missile guidance method in which a missile contains a radar transceiver (in contrast to semi-active radar homing, which uses only a receiver) and the electronics necessary for it to find and track its target au ...

system from

Western Electric The Western Electric Company was an American electrical engineering and manufacturing company officially founded in 1869. A wholly owned subsidiary of American Telephone & Telegraph for most of its lifespan, it served as the primary equipment ma ...

with a (one

short ton The short ton (symbol tn) is a measurement unit equal to . It is commonly used in the United States, where it is known simply as a ton, although the term is ambiguous, the single word being variously used for short, long, and metric ton. The vari ...

) general-purpose (GP) bomb, the same basic "AN-M66" ordnance unit as used for the heavier

USAAF The United States Army Air Forces (USAAF or AAF) was the major land-based aerial warfare service component of the United States Army and ''de facto'' aerial warfare service branch of the United States during and immediately after World War II ...

VB-2 version of the

Azon AZON (or Azon), from " azimuth only", was one of the world's first guided weapons, deployed by the Allies and contemporary with the German Fritz X. Officially designated VB-1 ("Vertical Bomb 1"), it was invented by Major Henry J. Rand and Thoma ...

radio-controlled ordnance. This Pelican version entered testing in summer 1944 at

Naval Air Station New York A navy, naval force, or maritime force is the branch of a nation's armed forces principally designated for naval and amphibious warfare; namely, lake-borne, riverine, littoral, or ocean-borne combat operations and related functions. It include ...

, where it hit its target ship in two out of four drops.

Development

The Bat was the production version which combined the original NBS airframe with a AN-M65 GP bomb, the same basic ordnance that was used in the contemporary

guided munition, and the Pelican active radar system. Gyrostabilized with an

autopilot An autopilot is a system used to control the path of an aircraft, marine craft or spacecraft without requiring constant manual control by a human operator. Autopilots do not replace human operators. Instead, the autopilot assists the operator' ...

supplied by

Bendix Aviation Bendix Corporation is an American manufacturing and engineering company which, during various times in its existence, made automotive brake shoes and systems, vacuum tubes, aircraft brakes, aeronautical hydraulics and electric power systems, ...

, the steerable tail elevator was powered by small wind-driven generators. The Navy's

in partnership with the

Massachusetts Institute of Technology The Massachusetts Institute of Technology (MIT) is a Private university, private Land-grant university, land-grant research university in Cambridge, Massachusetts. Established in 1861, MIT has played a key role in the development of modern t ...

(MIT) supervised development and the NBS was in charge of the overall development. Flight tests were conducted at the Naval Air Ordnance Test Station at Chincoteague Island, Virginia.

Hugh Latimer Dryden Hugh Latimer Dryden (July 2, 1898 – December 2, 1965) was an American aeronautical scientist and civil servant. He served as NASA Deputy Administrator from August 19, 1958, until his death. Biography Early life and education Dryden was born in ...

won the

President's Certificate of Merit The President's Certificate of Merit was created June 6, 1946 by Executive Order 9734 signed by US President Harry Truman, "for award by the President or at his direction to any civilian who on or after December 7, 1941'' (see Attack on Pearl Harbor ...

for the development of the Bat, which "was flight tested by a small unit based at Philadelphia against targets in New Jersey." While the NBS developed the Bat's aerodynamic and gyroscopic stabilizing systems, MIT and Bell Labs worked together on its guidance mechanism.

Deployment

The antiship variant of the Bat (SWOD, for "Special Weapons Ordnance Device", Mark 9 Modification 0) eventually saw combat service beginning in April 1945 off

Borneo Borneo (; id, Kalimantan) is the List of islands by area, third-largest island in the world and the largest in Asia. At the geographic centre of Maritime Southeast Asia, in relation to major Indonesian islands, it is located north of Java Isl ...

, dropped by

Consolidated PB4Y Privateer The Consolidated PB4Y-2 Privateer is an American World War II and Korean War era patrol bomber of the United States Navy derived from the Consolidated B-24 Liberator. The Navy had been using B-24s with only minor modifications as the PB4Y-1 Li ...

s (one bomb mounted under each wing) at altitudes of at airspeeds of . Several Japanese ships were sunk and the kaibokan '' Aguni'' was damaged from a range of , which is frequently miscredited as being sunk by a destroyer. Several Bats were also fitted with modified radar systems (SWOD Mark 9 Model 1) and dropped on Japanese-held bridges in

Burma Myanmar, ; UK pronunciations: US pronunciations incl. . Note: Wikipedia's IPA conventions require indicating /r/ even in British English although only some British English speakers pronounce r at the end of syllables. As John C. Wells, Joh ...

– the same targets that the

MCLOS Manual command to line of sight (MCLOS) is a method for guiding guided missiles. With an MCLOS missile, the operator must track the missile and the target simultaneously and guide the missile to the target. Typically the missile is steered with a ...

-guidance, half-ton (AN-M65 GP bomb) weight VB-1

PGM ordnance was designed to take on – and other land-based targets. The Bat's pioneering radar guidance system was easily confused by radar land clutter, particularly against targets close to shore. About a total of 2,600 Bat missiles were deployed. After the war, the naval designation ASM-N-2 was applied to the unit. The Privateer was the primary launch platform for the Bat, but other aircraft were also modified to launch the weapon, including the

Vought F4U Corsair The Vought F4U Corsair is an American fighter aircraft which saw service primarily in World War II and the Korean War. Designed and initially manufactured by Chance Vought, the Corsair was soon in great demand; additional production contract ...

Curtiss SB2C Helldiver The Curtiss SB2C Helldiver is a dive bomber developed by Curtiss-Wright during World War II. As a carrier-based bomber with the United States Navy (USN), in Pacific theaters, it supplemented and replaced the Douglas SBD Dauntless. A few surviv ...

, and

Grumman TBF Avenger The Grumman TBF Avenger (designated TBM for aircraft manufactured by General Motors) is an American World War II-era torpedo bomber developed initially for the United States Navy and Marine Corps, and eventually used by several air and naval ...

. The primary post-World War II aircraft to carry the weapon was the

P-2 Neptune The Lockheed P-2 Neptune (designated P2V by the United States Navy prior to September 1962) is a maritime patrol and anti-submarine warfare (ASW) aircraft. It was developed for the US Navy by Lockheed to replace the Lockheed PV-1 Ventura and ...

Existing missiles

The original NBS test airframe of the Bat was renovated in 2001 to resemble the real missile and is currently on display at the museum of the

National Institute of Standards and Technology The National Institute of Standards and Technology (NIST) is an agency of the United States Department of Commerce whose mission is to promote American innovation and industrial competitiveness. NIST's activities are organized into Outline of p ...

, the successor to the earlier US National Bureau of Standards.

References

External links