ASM-N-2 Bat

ASM-N-2 Bat
Bat guided bomb mated to PB4Y Privateer
TypeConventional
Place of originUnited States
Service history
In service1945 (Bomb MK 57) – 1953 (ASM-N-2)
Used byUnited States Navy
WarsWorld War II
Production history
ManufacturerNational Bureau of Standards
No. built2,580
Specifications
MassAirframe and guidance package only – 600 pounds (270 kg)
Length11 feet 11 inches (3.63 m)
Width10 feet (3.0 m)
Filling weight1,000 lb bomb (1,600 lb (727 kg) gross)
A Bat on its hoist

The ASM-N-2 Bat, originally designated as the Bomb MK 57 and later as the SWOD Mk 9, was a United States Navy World War II radar-guided glide bomb which was used in combat beginning in April 1945. The Bat was developed and manufactured by a unit within the National Bureau of Standards (later a part of the Army Research Laboratory), with assistance from the U.S. Navy's Bureau of Ordnance, the Massachusetts Institute of Technology, and Bell Telephone Laboratories. It is considered to be the first fully automated guided missile used in combat.

Background

In January 1941, RCA proposed a new TV-guided anti-ship weapon called the Dragon, where the operator would use the TV image sent from the nose of the weapon and maneuver it during the weapon's fall. The National Bureau of Standards (NBS) would provide the ordinance airframe for the weapon idea, which was the same airframe design used for the cancelled pigeon-guided Project Pigeon and semi-active radar-guided Pelican programs.

By mid-1943, a modification of the Pelican’s design was proposed, which would replace the cancelled program’s semi-active system with a new active radar homing system from Western Electric, and pair it with a AN-M66 2,000-pound (907 kg) (one short ton) general-purpose (GP) bomb, the same ordnance unit as used for the heavier VB-2 version of the Azon guided bomb used by the US Army Air Force. This Pelican version entered testing in mid-1944 at Naval Air Station New York, where it hit its target ship in two out of four drops.

Development

The production version of the project reused the original NBS airframe and paired it with the AN-M65 1,000-pound (454 kg) GP bomb, the same basic ordnance that was used in the original VB-1 Azon bomb and Pelican program. The missile was gyrostabilized with an autopilot system supplied by Bendix Aviation and steerable by a tail elevator that was powered by small wind-driven generators. While the NBS and Bendix developed the Bat's aerodynamic and gyroscopic stabilizing systems, MIT and Bell Labs worked together on its guidance mechanism. The Navy's Bureau of Ordnance, in partnership with MIT, supervised the missile’s development, with the NBS in charge of the overall development.

Flight tests were conducted at the Naval Air Ordnance Test Station at Chincoteague Island, Virginia, and "was flight tested by a small unit based at Philadelphia against targets in New Jersey" at the future Warren Grove Range . NBS Aerodynamics Division director Hugh Latimer Dryden would go on to win the President's Certificate of Merit for the development of the Bat.

Deployment

A Bat weapon on a bomb cart, with its nose radome removed

The missile was introduced into combat service in January of 1945. The anti-ship variant of the missile, the SWOD (“Special Weapons Ordnance Device") Mk.9 Mod 0 was introduced into combat service in April 1945.

On May 27, 2945, Consolidated PB4Y Privateers flying off the coast of Borneo with one bomb mounted under each wing dropped SWODs at altitudes of 15,000 to 25,000 feet (4,600 to 7,600 metres) and airspeeds of 140 to 210 kn (260 to 390 km/h), sinking several Japanese ships and damaging the kaibokan Aguni from a range of 20 nmi (37 km); this vessel is frequently misreported as having been sunk by a destroyer. Several Bats were later fitted with modified radar systems (SWOD Mk 9 Mod 1) and dropped on Japanese-held bridges and other land-based targets in Burma. The Bat's radar guidance system frequently got confused by radar land clutter, particularly against targets close to shore. A total of approximately 2,600 Bat missiles were deployed throughout World War II.

After the end of the war, the naval designation ASM-N-2 was applied to the unit.

The PB4Y Privateer was the primary launch platform for the Bat throughout World War II, but other aircraft were also modified to launch the weapon, including the Vought F4U Corsair, Curtiss SB2C Helldiver, and Grumman TBF Avenger. The primary post-war aircraft to carry the weapon was the Lockheed P2V Neptune, until the Bat was retired from service in 1953.

Missiles on display

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 successor to the earlier US National Bureau of Standards. Another example is on display at the Pima Air & Space Museum in Tucson, Arizona.

See also

Related lists

References

  1. ↑ "ASM-N-2". Directory of U.S. Military Rockets and Missiles. Archived from the original on 13 November 2007. Retrieved 24 December 2007.
  2. ↑ Kopp, Dr Carlo. "The Dawn of the Smart Bomb". Air Power Australia. Retrieved 24 December 2007.
  3. 1 2 3 "Missile, Air-to-Surface, Bat". Rockets and Missiles. Smithsonian National Air and Space Museum. Archived from the original on 7 May 2009. Retrieved 12 May 2009.
  4. ↑ Newman, Michael E. "Students Help Renovate a Part of WWII-and NIST-History". NIST Tech Beat – February 2001 – Preservation. National Institute of Standards and Technology. Archived from the original on 2 April 2015. Retrieved 19 March 2015.
  5. 1 2 Sweeney, Jim (January 2002). "Restoration: The Bat". Air & Space Magazine. Retrieved 13 July 2018.
  6. 1 2 3 Materese, Robin (20 June 2017). "Giving New Wings to an Old Bat". NIST. Retrieved 13 July 2018.
  7. 1 2 3 Fahrney, Delmar S., RADM USN (December 1980). "The Birth of Guided Missiles". United States Naval Institute Proceedings. p. 60.{{cite web}}: CS1 maint: multiple names: authors list (link)
  8. ↑ Merrill, Capt Grayson (n.d.). "Innovation Wins Wars". Your story – Class of 1934. USNA Alumni Association and Foundation. Retrieved 7 January 2013. BAT was flight tested by a small unit based at Philadelphia against targets in New Jersey.
  9. ↑ SWOD
  10. ↑ "Japanese Escorts".
  11. ↑ "The Bat Missile". NIST. Archived from the original on 27 May 2010. Retrieved 7 June 2010.
  12. ↑ "Designation: ASM-N-2". Pima Air & Space Museum. 26 November 2019. Retrieved 6 July 2023.