Bofors 120 mm Automatic Gun L/46

Summary

Bofors 120 mm Automatic Gun L/46,[4] most commonly referred to as either Bofors FAK 120 or Bofors TAK 120 depending on the configuration (field gun vs naval gun), was a Swedish liquid-cooled single-barreled 120 mm (4.7 in) caliber long-range anti-aircraft autocannon designed by Bofors during the 1950s for indigenous use and export.[2][4]

Bofors 120 mm Automatic Gun L/46
Karjala 120 mm keulatykki Forum Marinum 4.JPG
Bofors 120 mm TAK 120 on Finnish Turunmaa-class gunboat
TypeAnti-aircraft autocannon
Place of originSweden
Service history
In service1968–present
Used byFAK 120

TAK 120

Production history
DesignerAB Bofors
Designed1963–1967
ManufacturerAB Bofors
No. builtFAK 120: 1 built
TAK 120: 6 built
VariantsFAK 120
TAK 120
Specifications
MassFAK 120: 23 t (51,000 lb)
TAK 120: 28 t (62,000 lb)
Barrel length5,520 mm (217 in) (with breech)
HeightFAK 120 height of fire: 1,950 mm (77 in)

Shell120 × 615 mm R Bofors
Shell weightComplete cartridge: 33.7 kg (74 lb)
High-Explosive shell: 21 kg (46 lb)
Explosive charge: 3.2 kg (7.1 lb)
Propellant charge: 5.5 kg (12 lb)
Caliber120 mm
Barrels1 × liquid-cooled
Recoil47 cm (19 in) nominal
ElevationFAK 120: -5°/+85°, 25°/s
TAK 120: -10°/+80°, 32°/s, acc 40°/s squared
TraverseFAK 120: 360°, 32°/s
TAK 120: 360°, 40°/s, acc 50°/s squared
Rate of fire75–80 rounds/min
Muzzle velocity810 m/s (2,700 ft/s)
Effective firing range08.0 seconds to 5,000 m
21.7 seconds to 10,000 m
Maximum firing range18,500 m at 45°
Feed system52 rounds in feed system
Referencesnavweaps.com,[1] tdf.chalmers.se,[2] fromtheswedisharchives.wordpress.com[3]

It was produced in two different variants during the 1950s and 1960s respectively, a field variant[4] and a naval variant,[1] and the latter still being in service today with the Indonesian Navy.[1]

VariantsEdit

The Bofors 120 mm Automatic Gun L/46 was throughout its product life produced in two different main-variants, a field version named FAK 120 and a naval version named TAK 120.

Bofors FAK 120Edit

 
Bofors FAK 120 in firing mode.
 
Bofors FAK 120 in transport mode.

The 120 mm Automatic Gun L/46 On Field Carriage,[3] also sold under the name Bofors 120 mm Automatic A.A. (Anti-Air) Field Gun L/46,[4] but most commonly known as the FAK 120,[3] was the initial variant of the Bofors 120 mm Automatic Gun L/46.[3] During development it was initially known as the FAK 120 X 53, were "FAK" means Field Automatic Gun (Swedish: fältautomatkanon), "120" being the caliber (120 mm) and "X 53" meaning model of 1953.[3] It was developed during the 1950's to meet a request from the Swedish Army for a new long range anti-aircraft gun capable of engaging aircraft at high altitude with a high rate of fire. This request lead to a 120 mm (4.7 in) caliber fully automatic medium-high velocity gun with a high capacity magazine and a high rate of fire, mounted on a field carriage.[3]

The initial plan was to acquire 6 guns for trial, only one prototype was produced.[3] The prototype was designated 12 cm luftvärnsautomatkanon försöksmodell 1 (12 cm lvakan fm 1), meaning 12 cm automatic anti-aircraft gun trial-model 1.[3] During trials the gun showed great performance but the advent of anti-aircraft missiles at the end of the 1950s meant that the project was a dead end and no more guns were ordered. Despite this the prototype was put into service as the 12 cm luftvärnsautomatkanon 4501 (12 cm lvakan 4501) and would see service with the Swedish air defense from 1960 to 1973 before being retired.[3]

FAK 120 technical description

The FAK 120 gun had a liquid-cooled gun barrel with exchangeable liner and a petrol-engine driven electro-hydraulic laying machinery for remote control. Hand-laying with cranks was also and option. The turret had space for two crew to aim the gun. The gun with magazines was mounted in an oscillating mount in between two covered gunner housings protected by 4 mm (0.16 in) of steel armor. The elevating mass was fitted with two separate magazines instead of a single one. The total ammunition capacity for both the gun and magazines was 52 shells and the automatic rate of fire was around 75 to 80 rounds per minute.[3]

The field mount was designed to be converted to a trailer by connecting a back and front part equipped with wheels and truck mount respectively. The wheel base was 5,790 mm (228 in) and the wheel track was 2,730 mm (107 in). Ground clearance was 395 mm (15.6 in).[3]

Bofors TAK 120Edit

 
Bofors TAK 120 turret.

The 120 mm Automatic Gun L/46 In Turret Mounting,[1] most commonly known as the TAK 120, was a 1960s navalized version of the Bofors FAK 120 field gun design from 1953.[2] The name TAK 120 means means Turret Automatic Gun 120 mm (Swedish: Tornautomatkanon 120 mm).[1]

The Bofors TAK 120 was a private export venture to quickly develop a modern gun system intended for large Fast Attack Craft (FAC).[1] To achieve this Bofors decided to simply do a navalized version of their 120 mm Automatic Field Gun L/46 (FAK 120).[2] As part of the navalization process, the TAK 120 gun was fitted into an enclosed gun turret, replacing the more open oscillating system used on the FAK 120 field gun. Due to the enclosed turret, the magazine capacity was slightly decreased.[2] The elevation mechanism was also shifted by 5° degrees downwards to increase the maximum gun depression from -5°[4] to -10°,[1] but at the cost of maximum elevation, going from +85°[4] to +80°.[1]

The Bofors TAK 120 never saw massive success on the export market but was exported to both the Finnish Navy and Indonesian Navy and it is still in service today with the latter.[1]

Ships fitted with the Bofors TAK 120Edit

 
Turunmaa-class gunboat Karjala (04) with TAK 120.
 
KRI Fatahillah (361) with TAK 120.
  Finnish Navy
  • Turunmaa (03)
  • Karjala (04)
  Indonesian Navy

See alsoEdit

ReferencesEdit

NotesEdit

  1. ^ a b c d e f g h i "120 mm/46 (4.7") TAK120". navweaps.com. Archived from the original on 2016-07-22. Retrieved 2021-12-19.
  2. ^ a b c d e "120 mm Anti Aircraft Gun 4501". tfd.chalmers.se. Archived from the original on 2007-05-18. Retrieved 2021-12-19.
  3. ^ a b c d e f g h i j k "The worlds largest autocannon". fromtheswedisharchives.wordpress.com. 4 November 2018. Archived from the original on 2021-01-28. Retrieved 2022-01-09.
  4. ^ a b c d e f Bofors (in Swedish). Karlskoga, Sweden: AB Bofors, Karlskoga (Boforskoncernen). 1958. p. 74.