Bofors 120 mm Automatic Anti-Aircraft Gun L/46

Bofors 120 mm Automatic A.A. Gun L/46
Bofors 120 mm TAK 120 on Finnish Turunmaa-class gunboat
Type	Anti-aircraft autocannon
Place of origin	Sweden
Service history
In service	1968 – today
Used by	FAK 120 Sweden Army TAK 120 Finnish Navy Indonesian Navy
Production history
Designer	AB Bofors
Designed	1963 – 1967
Manufacturer	AB Bofors
No. built	FAK 120: 1 built TAK 120: 6 built
Variants	FAK 120 TAK 120
Specifications
Mass	FAK 120: 23 t (51,000 lb) TAK 120: 28 t (62,000 lb)
Barrel length	5,520 mm (217 in) (with breech)
Height	FAK 120 height of fire: 1,950 mm (77 in)
Shell	120 × 615 mm R Bofors
Shell weight	Complete cartridge: 337 kg (743 lb) Propellant charge: 5.5 kg (12 lb) High-Explosive shell: 21 kg (46 lb) Bursting charge: 3.2 kg (7.1 lb)
Caliber	120 mm
Barrels	1 × liquid-cooled
Recoil	47 cm (19 in) nominal
Elevation	FAK 120: -5°/+85°, 25°/s TAK 120: -10°/+80°, 32°/s, acc 40°/s squared
Traverse	FAK 120: 360°, 32°/s TAK 120: 360°, 40°/s, acc 50°/s squared
Rate of fire	75 – 80 rounds/min
Muzzle velocity	810 m/s (2,700 ft/s)
Effective firing range	08.0 seconds to 5,000 m 21.7 seconds to 10,000 m
Maximum firing range	18,500 m at 45°
Feed system	52 rounds in feed system
References	navweaps.com, tdf.chalmers.se, fromtheswedisharchives.wordpress.com

Bofors 120 mm Automatic Anti-Aircraft Gun L/46, most commonly referred to as either Bofors FAK 120 or Bofors TAK 120 depending on the configuriation (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.

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

Variants

The Bofors 120 mm Automatic A.A. 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 120

Bofors FAK 120 in firing mode.

Bofors FAK 120 in transport mode.

The 120 mm Automatic Gun L/46 On Field Carriage, also sold under the name Bofors 120 mm Automatic A.A. Field Gun L/46, but most commonly known as the FAK 120, was the initial variant of the Bofors 120 mm Automatic Anti-Aircraft Gun. During development it was initially known as the FAK 120 X 53, were "FAK" means Field Automatic Gun (Swedish language: fältautomatkanon ), "120" being the caliber (120 mm) and "X 53" meaning model of 1953. 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.

The initial plan was to acquire 6 guns for trial, only one prototype was produced. The prototype was designated 12 cm luftvärnsautomatkanon försöksmodell 1 (12 cm lvakan fm 1), meaning 12 cm automatic anti-aircraft gun trial-model 1. 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.

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 minutre.

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).

Bofors TAK 120

Bofors TAK 120

The 120 mm Automatic Gun L/46 In Turret Mounting, most commonly known as the TAK 120, was a 1960s navalized version of the Bofors FAK 120 field gun design from 1953. The name TAK 120 means means Turret Automatic Gun 120 mm (Swedish language: Tornautomatkanon 120 mm ). The Bofors TAK 120 was a private export venture to quickly develop a modern gun system intended for large Fast Attack Craft (FAC). To achieve this Bofors decided to simply do a navalized version of their 120 mm Automatic Field Gun L/46 (FAK 120). 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. The elevation mechanism was also chifted by 5° degrees downards to increase the maximum gun depression from -5° to -10°, but at the cost of maximum elevation, going from +85° to +80°.

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.

Ships fitted with the Bofors TAK 120

Turunmaa-class gunboat Karjala (04)

KRI Fatahillah (361)

Finnish Navy

• Turunmaa-class gunboat:

• Turunmaa (03)
• Karjala (04)

• Finnish minelayer Pohjanmaa (replaced with Bofors 57 mm Naval Automatic Gun L/70 Mk1 1996-98)

Indonesian Navy

• Fatahillah-class corvette:

• KRI Fatahillah (361)
• KRI Malahayati (362)
• KRI Nala (363)

See also

• Bofors 120 mm Naval Automatic Gun L/50