Bofors 57 mm gun

Bofors 57 mm
300px Bofors 57 mm Mk 1, as mounted on the Swedish Spica-II Class FAC.
Type	Naval gun
Place of origin	Sweden
Service history
In service	1966 - present
Used by	See users
Production history
Designer	Bofors Defence
Designed	Mark 1: 1964 Mark 2: 1981 Mark 3: 1995
Manufacturer	Bofors Defence (1966-2006) BAE Systems AB (2006 onwards)
Produced	Mark 1: 1966 Mark 2: 1985 Mark 3: 1998
Variants	Mark 1, Mark 2, Mark 3 & Mk 110.
Specifications
Weight	Mark 3: 14,000 kg (weight including 1,000 rounds onboard) 6.5 kg (complete round)
Shell	57 mm × 438 mm
Caliber	70 caliber 57 mm
Elevation	Mark 1: -10°/+78°(40°/s) Mark 2: -10°/+75°(40°/s) Mark 3: -10°/+77°(44°/s)
Traverse	360° Mark 1 & 2: 55°/s Mark 3: 57°/s
Rate of fire	Mark 1: 200 rounds/min Mark 2 & Mark 3: 220 rounds/min
Muzzle velocity	1,035 m/s (HE round)
Effective range	8,500 m (HE round)
Maximum range	17,000 m (HE round at 45°)
Feed system	Magazine: Mark 1 - 40 ready rounds, 128 rounds in ready racks in mount. Mark 2 - 120 ready rounds, up to 40 rounds in dual hoists. Mark 3 - 120 ready rounds, up to 40 rounds in dual hoists, 1,000 rounds in mounting.
Sights	Gyro-stabilized in local control.

The Bofors 57 mm gun are a series of dual-purpose naval guns, produced and originally designed by Bofors Defence (now a part of BAE Systems).

Design

The Bofors 57 mm has a 120-round magazine and a rate of fire of about 220 shots/minute. The rate of fire and the ability to change ammunition types quickly makes the gun suitable for engaging both aerial and naval targets. Normally a computer aims the gun, giving it high accuracy. However, the crew can also train and aim the gun using instrument panels that are either on or in direct contact with the gun.

Deployments

The Swedish Navy is the primary user of the gun and Bofors Defence has exported it for use by navies of Canada, Croatia, Finland, Indonesia, Malaysia, Mexico, Netherlands, Singapore and Thailand.

Main article: Mk 110 57 mm gun

The Mk 3 version with stealth turret housing will enter US naval service as the Mk 110 57 mm gun.

Versions

Bofors 57 mm/L70

Bofors 57 mm Mk 1

Bofors developed the Mk 1 from the Bofors 57 mm/L60 in 1962. Improvements included a higher rate of fire, the use of new munitions including an improved proximity fuse, water cooling for the gun tubes and a new electro-hydraulic system for rapid training and elevation. Finland, Malaysia, Norway, Indonesia, Singapore and (the former) Yugoslavia are among the countries that adopted the Mk 1.

Bofors 57 mm Mk 2

The Mk 2 was a lighter weight version, which utilized a new servo system. Bofors designed the gun in 1981 and it entered active service on the Stockholm Class Corvette in 1985. The gun was partly dual-purpose in the sense that it is accurate and agile enough to destroy sea-skimming missiles. Bofors manufactured a total of about 50 Mk 2 guns.

Main article: 57 Mk3

Bofors 57 mm Mk 3

The Mk3 is the latest version of the gun. Bofors designed it in 1997 and it entered service in 2002. The gun uses smart ammunition but can also fire the same ammunition as the Mk 2. The stealth variant has a reduced radar profile, in part by hiding the gun barrel when it is not firing. The gun has a small radar mounted on the gun barrel to measure muzzle velocity for fire control purposes. The gun can change ammunition types instantly, thanks to a dual-feed system.

Users

Mark 1

• Template:CRO:
  • Kralj class
  • Končar class
• Finland:
  • Pohjanmaa class
  • Hämeenmaa class
  • Helsinki class missile boat
• Template:INA
  • Andau class (Lürssen FPB 57-I)
  • Mandau class (modified version of the South Korean Navy's Bae Ku class, which was based on the U.S. Navy's Asheville class)
• Ireland
  • Eithne class
• Malaysia:
  • Kasturi class frigate
  • Perdana class (Combattante-II 4AL) missile boat
  • Handalan class (Spica-M)
  • Jerong class (Lurssen TNC 45)
• Netherlands
  • De Zeven Provinciën class cruiser (acquired by Peruvian Navy as the BAP Almirante Grau (CLM-81), guns were removed during a refit in 1988)

File:RSS P78 01.jpg

RSS Sea Dragon with its 57 mm Mk 1.

• Template:SIN:
  • Sea Wolf class (Lurssen TNC 45)
• Sweden:
  • Hugin class
  • Spica class
  • Spica II class
• Thailand
  • Prabbrorapak class (Lurssen TNC 45)

Mark 2

File:57 mk2.jpg

A 57 mm Mk 2 firing from a Halifax class frigate.

• Canada:
  • Halifax class frigate
• Template:INA
  • Pandrong class (Lürssen FPB 57-II)
• Malaysia:
  • Lekiu class frigate

File:HMS Gävle.JPG

Swedish Navy's HMS Gävle

• Sweden:
  • Stockholm class corvette
  • Göteborg class corvette

Mark 3

• Finland:
  • Hamina class missile boat
• Template:MEX:
  • Sierra class corvette
  • Durango class patrol vessel
• Sweden:
  • Visby class corvette
• United States:
  • USCG: Legend class
  • USN: Zumwalt class
  • USN: Freedom class
  • USN: Independence class

External links

• Discovery Channel website - Watch the Bofors 57 mm gun fires and reload!
• Bofors Defence - Naval Guns and Programmable Ammunition
• Bofors 57 mm L70
• Bofors 57mm MK3 Naval Gun System
• 57-mm Mk 110 Mod 0 Naval Gun System

"Naval vessels as built by Lurssen GmbH". Lurssen.com.