Bofors 57 mm gun
Encyclopedia
The Bofors 57 mm guns are a series of dual-purpose naval guns designed and produced by the Swedish
defence firm
of Bofors Defence
(the company was acquired in September 2000 by United Defense Industries
but is now a part of BAE Systems AB since March 2005). Designed in 1964, production of the baseline 57 mm Mark 1 variant began in 1966 and was used to equipped initially smaller coastal patrol craft and fast attack craft. The gun was upgraded and improved several times, first as the Mark 2 in 1981 and the Mark 3 in 1995.
Most recently, it was offered by BAE Systems AB (successor of Bofors Defence AB) as the Mk 110 57 mm gun (essentially a slightly modified Mark 3) for use by the United States Coast Guard
in 2004 and the United States Navy
in 2006.
The gun is usually controlled by a fire-control computer but as a redundancy measure, the crew can also train and aim the gun using instrument panels that are either on or in direct contact with the gun.
Although the Swedish Navy
is the primary user of the gun, it has been exported widely by Bofors Defence for use by the navies of Brunei
, Canada
, Croatia
, Finland
, Indonesia
, Ireland
, Malaysia, Mexico
, Montenegro
, Singapore
, Thailand
and the United States
.
fast attack craft (FAC)
of Swedish Navy
in 1966, it has a rate of fire of 200 rounds per minute and a 40-round magazine in the gun turret
with a further 128 rounds stowed inside. With minor modifications, the Mark 1 guns could use ammunition
s developed for the Mark 2 gun.
The Mark 2 was designed in 1981 but introduced into service with the - HMS Stockholm (K11) in 1985 (sister ship HMS Malmö (K12) was built in 1984 but armed with the older Mk 1, subsequently retrofitted with the Mk 2 in 2009), the rate of fire was slightly increased to 220 rounds per minute. Also, it featured a new light weight gun turret with a new gun barrel
that was forged
from monobloc steel (this eliminated the need to use a water jacket for gun barrel cooling during firing) and a new servo drive
/servomechanism
system (for faster reaction time and better gun aiming and control). According to Bofors, the new servo system allowed the Mk 2 to be both accurate and agile enough for used against sea skimming
anti-ship missile
s and that it could put more explosives into a surface target within a thirty seconds window than any naval gun with a calibre smaller than 100 mm (3.9 in).
The latest development is the Mark 3, which was designed in 1995 but introduced into service with the - fitted on HMS Visby (K31)
in 2000. This new design retained the Mark 2 gun turret, rate of fire and ammunition capacity and has another 1,000 rounds stowed in the standby rack beneath deck. A small radome
has been added above the gun barrel and is used for measuring the muzzle velocity
of the departing projectiles for fire-control purposes
, usually but not necessarily with the new Bofors 57 mm 3P all-target programmable ammunition. Also, a new optional low radar profile (also known as low radar cross-section, or RCS) stealth mounting was developed, this allows the gun to be hidden from radar and plain sight when not in use.
In American service, the United States Navy has designated the Mark 3 as the Mark 110 Mod0 57mm gun. According to a BAE press release dated 1 August 2005, the Mark 110 would be manufactured at the BAE Systems facility in Louisville, Kentucky
.
in Finland, SME Ordnance
in Malaysia and Nammo
in Norway.
Since 2006, BAE Systems AB began to offer the Bofors 57 mm 3P all-target programmable ammunition, this allows 3 proximity fuzing modes
as well as settings for time, impact, and armor piercing functions. This increases the flexibility and effectiveness of the gun system, which has further reduced the reaction time of the gun and it is possible to choose ammunition mode at the moment of firing, giving it the ability to switch rapidly between surface targets, air targets as well as ground targets.
Bofors developed the Mark 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 Mark 1.
Bofors 57 mm Mk 2
The Mark 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 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 25 Mk 2 guns.
Bofors 57 mm Mk 3
The Mark 3 is the latest version of the gun. Bofors designed it in 1996 and it entered service in 2000. 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. Also, the gun has a small radar mounted on the gun barrel to measure muzzle velocity for fire control purposes and it can change ammunition types instantly due to a dual-feed system.
Mk 110 57 mm gun
The Mark 110 57 mm gun is the US version of the Bofors 57 mm Mark 3 gun, while the Bofors 57 mm 3P ammunitions are designated as Mark 295 Mod0 in US service.
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Mark 2
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Mark 3/Mk 110 57 mm gun
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Video links
Sweden
Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....
defence firm
Defense contractor
A defense contractor is a business organization or individual that provides products or services to a military department of a government. Products typically include military aircraft, ships, vehicles, weaponry, and electronic systems...
of Bofors Defence
Bofors
The name Bofors has been associated with the iron industry for more than 350 years.Located in Karlskoga, Sweden, the company originates from the hammer mill "Boofors" founded 1646. The modern corporate structure was created in 1873 with the foundation of Aktiebolaget Bofors-Gullspång...
(the company was acquired in September 2000 by United Defense Industries
United Defense
United Defense Industries was a United States defense contractor which is now part of BAE Systems Land and Armaments. This company produces combat vehicles, artillery, naval guns, missile launchers and precision munitions.-History:...
but is now a part of BAE Systems AB since March 2005). Designed in 1964, production of the baseline 57 mm Mark 1 variant began in 1966 and was used to equipped initially smaller coastal patrol craft and fast attack craft. The gun was upgraded and improved several times, first as the Mark 2 in 1981 and the Mark 3 in 1995.
Most recently, it was offered by BAE Systems AB (successor of Bofors Defence AB) as the Mk 110 57 mm gun (essentially a slightly modified Mark 3) for use by the United States Coast Guard
United States Coast Guard
The United States Coast Guard is a branch of the United States Armed Forces and one of the seven U.S. uniformed services. The Coast Guard is a maritime, military, multi-mission service unique among the military branches for having a maritime law enforcement mission and a federal regulatory agency...
in 2004 and the United States Navy
United States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...
in 2006.
The gun is usually controlled by a fire-control computer but as a redundancy measure, the crew can also train and aim the gun using instrument panels that are either on or in direct contact with the gun.
Although the Swedish Navy
Swedish Navy
The Royal Swedish Navy is the naval branch of the Swedish Armed Forces. It is composed of surface and submarine naval units – the Fleet – as well as marine units, the so-called Amphibious Corps .In Swedish, vessels of the Swedish Navy are given the prefix "HMS," short for Hans/Hennes...
is the primary user of the gun, it has been exported widely by Bofors Defence for use by the navies of Brunei
Brunei
Brunei , officially the State of Brunei Darussalam or the Nation of Brunei, the Abode of Peace , is a sovereign state located on the north coast of the island of Borneo, in Southeast Asia...
, Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
, Croatia
Croatia
Croatia , officially the Republic of Croatia , is a unitary democratic parliamentary republic in Europe at the crossroads of the Mitteleuropa, the Balkans, and the Mediterranean. Its capital and largest city is Zagreb. The country is divided into 20 counties and the city of Zagreb. Croatia covers ...
, Finland
Finland
Finland , officially the Republic of Finland, is a Nordic country situated in the Fennoscandian region of Northern Europe. It is bordered by Sweden in the west, Norway in the north and Russia in the east, while Estonia lies to its south across the Gulf of Finland.Around 5.4 million people reside...
, Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
, Ireland
Ireland
Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...
, Malaysia, Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
, Montenegro
Montenegro
Montenegro Montenegrin: Crna Gora Црна Гора , meaning "Black Mountain") is a country located in Southeastern Europe. It has a coast on the Adriatic Sea to the south-west and is bordered by Croatia to the west, Bosnia and Herzegovina to the northwest, Serbia to the northeast and Albania to the...
, Singapore
Singapore
Singapore , officially the Republic of Singapore, is a Southeast Asian city-state off the southern tip of the Malay Peninsula, north of the equator. An island country made up of 63 islands, it is separated from Malaysia by the Straits of Johor to its north and from Indonesia's Riau Islands by the...
, Thailand
Thailand
Thailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the...
and the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
.
Design and development
The baseline version of the Bofors 57 mm (2.2 in) L70 gun was the Mark 1, first introduced into service with the Spica-classHMS Spica (T121)
HMS Spica is a former Swedish Navy torpedo-armed fast attack craft , now a museum ship at the Vasa Museum in Stockholm, Sweden....
fast attack craft (FAC)
Fast Attack Craft
Fast Attack Craft are small, fast, agile and offensive warships, that are armed with anti-ship missiles, guns or torpedoes. These are usually operated in close proximity to land as they lack both the sea-keeping and all-round defensive capabilities to survive in blue water. The size of the vessel...
of Swedish Navy
Swedish Navy
The Royal Swedish Navy is the naval branch of the Swedish Armed Forces. It is composed of surface and submarine naval units – the Fleet – as well as marine units, the so-called Amphibious Corps .In Swedish, vessels of the Swedish Navy are given the prefix "HMS," short for Hans/Hennes...
in 1966, it has a rate of fire of 200 rounds per minute and a 40-round magazine in the gun turret
Gun turret
A gun turret is a weapon mount that protects the crew or mechanism of a projectile-firing weapon and at the same time lets the weapon be aimed and fired in many directions.The turret is also a rotating weapon platform...
with a further 128 rounds stowed inside. With minor modifications, the Mark 1 guns could use ammunition
Ammunition
Ammunition is a generic term derived from the French language la munition which embraced all material used for war , but which in time came to refer specifically to gunpowder and artillery. The collective term for all types of ammunition is munitions...
s developed for the Mark 2 gun.
The Mark 2 was designed in 1981 but introduced into service with the - HMS Stockholm (K11) in 1985 (sister ship HMS Malmö (K12) was built in 1984 but armed with the older Mk 1, subsequently retrofitted with the Mk 2 in 2009), the rate of fire was slightly increased to 220 rounds per minute. Also, it featured a new light weight gun turret with a new gun barrel
Gun barrel
A gun barrel is the tube, usually metal, through which a controlled explosion or rapid expansion of gases are released in order to propel a projectile out of the end at a high velocity....
that was forged
Forging
Forging is a manufacturing process involving the shaping of metal using localized compressive forces. Forging is often classified according to the temperature at which it is performed: '"cold," "warm," or "hot" forging. Forged parts can range in weight from less than a kilogram to 580 metric tons...
from monobloc steel (this eliminated the need to use a water jacket for gun barrel cooling during firing) and a new servo drive
Servo drive
A servo drive is a special electronic amplifier used to power electric servomechanisms.A servo drive monitors the feedback signal from the servomechanism and continually adjusts for deviation from expected behavior.-Function:...
/servomechanism
Servomechanism
thumb|right|200px|Industrial servomotorThe grey/green cylinder is the [[Brush |brush-type]] [[DC motor]]. The black section at the bottom contains the [[Epicyclic gearing|planetary]] [[Reduction drive|reduction gear]], and the black object on top of the motor is the optical [[rotary encoder]] for...
system (for faster reaction time and better gun aiming and control). According to Bofors, the new servo system allowed the Mk 2 to be both accurate and agile enough for used against sea skimming
Sea skimming
Sea skimming is a technique many anti-ship missiles use to avoid radar and infrared detection during their approach.-Method:Sea skimming anti-ship missiles try to fly as low as is practically achievable, which is almost always below 50 meters , and is often down towards 5 meters .-Advantages:By...
anti-ship missile
Anti-ship missile
Anti-ship missiles are guided missiles that are designed for use against ships and large boats. Most anti-ship missiles are of the sea-skimming type, many use a combination of inertial guidance and radar homing...
s and that it could put more explosives into a surface target within a thirty seconds window than any naval gun with a calibre smaller than 100 mm (3.9 in).
The latest development is the Mark 3, which was designed in 1995 but introduced into service with the - fitted on HMS Visby (K31)
HMS Visby (K31)
HMS Visby is the lead ship in the new class of s ordered by the Swedish Government and built by Kockums. She is currently in the Karlskrona Naval Yard being fitted with additional equipment slated for returning to her operational sea trials during the autumn 2008.-External links:* * - Official...
in 2000. This new design retained the Mark 2 gun turret, rate of fire and ammunition capacity and has another 1,000 rounds stowed in the standby rack beneath deck. A small radome
Radome
A radome is a structural, weatherproof enclosure that protects a microwave or radar antenna. The radome is constructed of material that minimally attenuates the electromagnetic signal transmitted or received by the antenna. In other words, the radome is transparent to radar or radio waves...
has been added above the gun barrel and is used for measuring the muzzle velocity
Muzzle velocity
Muzzle velocity is the speed a projectile has at the moment it leaves the muzzle of the gun. Muzzle velocities range from approximately to in black powder muskets , to more than in modern rifles with high-performance cartridges such as the .220 Swift and .204 Ruger, all the way to for tank guns...
of the departing projectiles for fire-control purposes
Fire-control system
A fire-control system is a number of components working together, usually a gun data computer, a director, and radar, which is designed to assist a weapon system in hitting its target. It performs the same task as a human gunner firing a weapon, but attempts to do so faster and more...
, usually but not necessarily with the new Bofors 57 mm 3P all-target programmable ammunition. Also, a new optional low radar profile (also known as low radar cross-section, or RCS) stealth mounting was developed, this allows the gun to be hidden from radar and plain sight when not in use.
In American service, the United States Navy has designated the Mark 3 as the Mark 110 Mod0 57mm gun. According to a BAE press release dated 1 August 2005, the Mark 110 would be manufactured at the BAE Systems facility in Louisville, Kentucky
Louisville, Kentucky
Louisville is the largest city in the U.S. state of Kentucky, and the county seat of Jefferson County. Since 2003, the city's borders have been coterminous with those of the county because of a city-county merger. The city's population at the 2010 census was 741,096...
.
Ammunitions
Ammunitions for the Bofors 57 mm gun are produced by Bofors, Sako LimitedSAKO
SAKO, Limited is a Finnish firearm manufacturer located in Riihimäki....
in Finland, SME Ordnance
SME Ordnance
The SME Ordnance Sdn Bhd company , formerly known as Syarikat Malaysia Explosive Sdn Bhd, is a Malaysian defense company that specializes in the manufacturing and marketing of ordnance...
in Malaysia and Nammo
Nammo
Nammo short for Nordic Ammunition Group is a Norwegian/Finnish military industry manufacturer of ammunition. The company has subsidiaries in Finland, Germany, Norway, Sweden, Switzerland, the United States and Canada. The company is owned 50/50 by the Norwegian Ministry of Trade and Industry and...
in Norway.
Since 2006, BAE Systems AB began to offer the Bofors 57 mm 3P all-target programmable ammunition, this allows 3 proximity fuzing modes
Proximity fuze
A proximity fuze is a fuze that is designed to detonate an explosive device automatically when the distance to target becomes smaller than a predetermined value or when the target passes through a given plane...
as well as settings for time, impact, and armor piercing functions. This increases the flexibility and effectiveness of the gun system, which has further reduced the reaction time of the gun and it is possible to choose ammunition mode at the moment of firing, giving it the ability to switch rapidly between surface targets, air targets as well as ground targets.
Bofors 57 mm/L70
Bofors 57 mm Mk 1Bofors developed the Mark 1 from the Bofors 57 mm/L60
57mm/60 modèle 1951 gun
The 57mm/60 modèle 1951 gun was a dual purpose artillery piece in use in the French Navy. They notably armed light escorts as main guns, and T47 fleet escorts....
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 Mark 1.
Bofors 57 mm Mk 2
The Mark 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 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 25 Mk 2 guns.
Bofors 57 mm Mk 3
The Mark 3 is the latest version of the gun. Bofors designed it in 1996 and it entered service in 2000. 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. Also, the gun has a small radar mounted on the gun barrel to measure muzzle velocity for fire control purposes and it can change ammunition types instantly due to a dual-feed system.
Mk 110 57 mm gun
The Mark 110 57 mm gun is the US version of the Bofors 57 mm Mark 3 gun, while the Bofors 57 mm 3P ammunitions are designated as Mark 295 Mod0 in US service.
Users
Mark 1-
- Kralj classKralj class fast attack craftThe Kralj class is a class of two fast attack craft, one of which was on order for the SFR Yugoslav Navy and one of which, following the break-up of Yugoslavia, was built for the Croatian Navy. As of 2009 both vessels remain in service....
- Končar classKončar class fast attack craftThe Končar class is a class of fast attack craft that was built for the SFR Yugoslav Navy in the late 1970s. Following the break-up of Yugoslavia one craft went to the Croatian Navy whilst the remaining five went to the Montenegro Navy...
- Kralj class
}:
-
- Pohjanmaa class
- Hämeenmaa classHämeenmaa class minelayerThe Hämeenmaa class minelayers is a two vessel strong class of minelayers, used by the Finnish Navy.The ships have a steel hull and alloy superstructure. The class has an ice operating classification of ICE-1A and can operate around the year...
- Andau class (Lürssen FPB 57-ILürssenLürssen is a German shipbuilding company based in Bremen-Vegesack.Lürssen designs and constructs yachts, naval ships and special vessels...
) - Mandau class (modified version of the South Korean NavyRepublic of Korea NavyThe Republic of Korea Navy or the ROK Navy is the branch of the South Korean armed forces responsible for conducting naval operations and amphibious landing operations. The ROK Navy includes the Republic of Korea Marine Corps, which is a quasi-autonomous organization...
's Bae Ku class, which was based on the U.S. NavyUnited States NavyThe United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...
's ) - Eithne classLÉ Eithne (P31)LÉ Eithne is an Eithne class ship in the Irish Naval Service. The ship is named after Eithne, a tragic heroine and the daughter of the one-eyed Fomorian King, Balor in an early Irish romantic tale....
:
}
-
- Perdana class (Combattante-II 4ALTiger class fast attack craftThe Type 148 Tiger class fast attack craft is a modification of the French La Combattante II design for the Bundesmarine . The La Combattante had been designed by Lürssen of Germany for Israel, but were built in France by Constructions Mécaniques de Normandie in Cherbourg for political reasons...
) missile boat - Handalan class (Spica-M)
- Jerong class (Lurssen TNC 45):
- Končar classKončar class fast attack craftThe Končar class is a class of fast attack craft that was built for the SFR Yugoslav Navy in the late 1970s. Following the break-up of Yugoslavia one craft went to the Croatian Navy whilst the remaining five went to the Montenegro Navy...
: - Sea Wolf class (Lurssen TNC 45):
- Hugin class
- Spica classHMS Spica (T121)HMS Spica is a former Swedish Navy torpedo-armed fast attack craft , now a museum ship at the Vasa Museum in Stockholm, Sweden....
- Spica II class
- Prabbrorapak class (derivative of Singapore's Sea Wolf class, which was based on the Lurssen TNC 45)
- Perdana class (Combattante-II 4AL
Mark 2
}
-
- Pandrong class/Todak class (2 and 4 ships respectively) (Lürssen FPB 57-II):
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Mark 3/Mk 110 57 mm gun
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- USCG: Legend classNational Security CutterThe United States Coast Guard National Security Cutter , also known as the Legend class and Maritime Security Cutter, Large, is one design among several new cutter designs developed as part of the Integrated Deepwater System Program....
- USN:
- USN:
- USN:
- USCG: Legend class
External links
- BBC article
- Bofors Defence - Naval Guns and Programmable Ammunition
- Bofors 57mm MK3 Naval Gun System
- Jane's info on Bofors 57 mm gun
- NavWeaps.Com: Bofors 57 mm/60
Video links