Bofors 120 mm Naval Automatic Gun L/50

Not to be confused with Bofors 120 mm Automatic Gun L/46 (FAK 120, TAK 120), or other Bofors 120 mm guns.

Bofors 120 mm Naval Automatic Gun L/50
Swedish 12 cm akan m/50 turret on Destroyer HMS Småland, 2008.
Type	Naval gun
Place of origin	Sweden
Service history
In service	1954 – 2001[1]
Used by	Royal Netherlands Navy  Swedish Navy  Colombian National Navy
Production history
Designer	AB Bofors
Designed	1950
Manufacturer	AB Bofors
No. built	54
Specifications
Mass	67,000 kg (148,000 lb)
Barrel length	L/50 (including breach)
Shell	120 × 835 mm R
Shell weight	23.35 – 23.5 kg
Caliber	120 millimetres (4.7 in)
Barrels	2 ×
Action	Automatic extraction with integrated autoloader
Elevation	-9°/+85°, 25°/s
Traverse	360°, 22°/s
Rate of fire	2 × 42 rounds/min
Muzzle velocity	835–850 m/s (2,740–2,790 ft/s)
References	Bofors 1958,[2] AMKAT Marinen, 1977[3]

Bofors 120 mm Naval Automatic Gun L/50 (full English name: Bofors 120 mm Automatic Gun L/50 In Naval Twin Turret),^[2] also known as Bofors 120 mm gun model 1950 and the like, was a Swedish twin-barreled 120 mm (4.7 in) caliber fully automatic dual purpose naval gun turret system designed by Bofors from the end of the 1940s to the early 1950s to meet a request from the Dutch Navy.^[4] Besides the Dutch Navy, the weapon was also adopted by the Swedish and the Colombian Navy.^[4]

Use in the Dutch Navy

The Dutch were the initial users of the Bofors 120 mm Naval Automatic Gun L/50. As part of rebuilding the Dutch Navy post WWII, the Dutch Navy had requested several naval gun systems to be developed by Bofors for their next generation of naval-vessels,^[5] one being a twin-barreled 120 mm dual-purpose gun for the then planned Holland-class destroyers.^[4] This request led to the creation of the Bofors 120 mm Naval Automatic Gun L/50.

• 
  Bofors 120 mm Naval Automatic Gun L/50 from the back onboard the stern of the Holland-class destroyer HNLMS Holland (D808).
• 
  Bofors 120 mm Naval Automatic Gun L/50 from the back left onboard the stern of the Holland-class destroyer HNLMS Noord-Brabant (D810).
• 
  Bofors 120 mm Naval Automatic Gun L/50 from the front left onboard the stern of the Holland-class destroyer HNLMS Gelderland (D811).

The gun entered active service with the Dutch Navy in 1954 mounted on the Holland-class destroyers. Even before the first Holland-class destroyer had been completed the Dutch Navy decided to order yet another class of destroyer armed with the Bofors 120 mm L/50, the Friesland-class destroyer. The Dutch really liked the design and decided in the mid 1970s to save two turrets from the Holland-class destroyer HNLMS Gelderland (D811) when she was decommissioned in 1973, and then fit them to the new Tromp-class frigates under construction.

Use in the Swedish Navy

HSwMS Halland (J18) aiming both of her 12 cm akan m/50 turrets (bow & stern), 1972.

Following the Dutch example, the Swedish Navy decided to acquire the new 120 mm system being developed for them and fit it to a new generation of destroyers in 1950. In Swedish service the weapon was fitted to the Halland-class destroyers HSwMS Halland (J18) and HSwMS Småland (J19), both of which entered service in 1956. The weapon was initially designated 12 cm automatkanon m/50 (12 cm akan m/50),^[6] lit. "12 cm autocannon m/50", but around 1970 the weapon was redesignated to 12 cm torndubbelautomatpjäs m/50 (12 cm tdblapjäs m/50), lit. "12 cm turret double automatic (artillery)piece m/50".^[7][8]

The gun was in use until the Halland-class destroyers were taken out of service.

• 
  Swedish 12 cm akan m/50 stern-turret on Destroyer HSwMS Halland (J18) 1960's.
• 
  Swedish 12 cm akan m/50 bow-turret on Destroyer HSwMS Småland (J19) 1960's.
• 
  Swedish 12 cm akan m/50 bow-turret on Destroyer HSwMS Småland (J19) 2010.

Use in the Colombian Navy

Swedish built Colombian Halland-class destroyer ARC 20 de Julio (D-05) fitted with three Bofors 120 mm Naval Automatic Gun L/50 turrets.

In Colombian service the Bofors 120 mm Naval Automatic Gun L/50 was fitted to the destroyers 7 de Agosto (D-06) and 20 de Julio (D-05), both of which were Swedish built Halland-class destroyers. Unlike the Swedish Halland-class destroyers, the Colombian version carried three Bofors 120 mm Naval Automatic Gun L/50 turrets instead of two.

See also

• Bofors 57 mm Naval Automatic Gun L/60
• Bofors 120 mm Automatic Gun L/46

Notes

Citations

1. van Beveren, Arthur (17 September 2024). "Materieel van toen: Bofors kanon van 12 cm, nummer 10". Materieelgezien (in Dutch). Defensie.nl.
2. Bofors (in Swedish). Karlskoga, Sweden: AB Bofors, Karlskoga (Boforskoncernen). 1958. p. 88.
3. AMKAT, Ammunitionskatalog, Data och bilder, Marinen, 1977 års utgåva (in Swedish). Stockholm, Sweden: Swedish Defence Materiel Administration (FMV). 1977.
4. "120 mm Bofors naval guns". tfd.chalmers.se. Archived from the original on 2007-05-18. Retrieved 2021-11-19.
5. "Bofors automatic 57mm Dual-Purpose guns". tfd.chalmers.se. Archived from the original on 2007-07-01. Retrieved 2021-09-14.
6. Amreg Fl, Ammunitionsregister för flottan, 1955 (in Swedish). Stockholm, Sweden: Ammunitionssektionen, Marinförvaltningens Artilleribyrå. 1955.
7. Amreg Marinen, Ammunitionsregister för marinen, 1962, ändringar 1965 (in Swedish). Stockholm, Sweden: Kungliga Marinförvaltningen. 1965.
8. AMKAT, Ammunitionskatalog, Data och bilder, Marinen, 1977 års utgåva (in Swedish). Stockholm, Sweden: Swedish Defence Materiel Administration (FMV). 1977.

Bibliography

• Borgenstam Insulander Kaudern; "Jagare". Karlskona 1989. CB Marinlitteratur. ISBN 91-970700-41
• 12 cm luftvärnsautomatkanon m/50 tekniskt beskrivning fastställd 1951. (12 cm anti air autocannon m/50 technical description established 1951) booklet.