FH-70

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FH 70

Type	Close support gun
Place of origin	UK, Germany, Italy
Service history
In service	1978
Used by	see text
Specifications
Weight	7,800-9,600
Barrel length	39
Crew	8

Caliber	155 mm
Carriage	Split trail, sole plate, auxiliary power unit and hydraulics
Elevation	-100 to +1250 mils
Traverse:	500 mils left and right
Rate of fire	burst 3 rounds in 15 seconds, 3-6 rounds per minute
Muzzle velocity	827 m/s
Effective range	24-30 km (depending on ammo)

The FH-70 (Field Howitzer for the 1970s) is a towed howitzer in use with several nations.

1 History
2 Design
3 Ammunition
4 Operators
5 References
6 External link

[edit] History

In 1963 NATO agreed a NATO Basic Military Requirement 39 for close support artillery, either towed or tracked. Subsequently Germany and UK started discussions and design studies and in 1968 established Agreed Operational Characteristics for a towed 155 mm close support gun. Italy became a party to the agreeement in 1970.

Key requirements were a detachable Auxiliary Power Unit (APU), an unassisted range of 24 km, 30 km assisted, a burst capability of 3 rounds in 15-20 seconds, 6 rounds per minute for a short period and 2 rounds per minute sustained. The gun was to fire all 155 mm munitions in NATO service and have a new range of ammunition.

The two national athorities had overall responsibility for R & D, and Vickers Ltd was the co-ordinating design authority. They were also the design authority for the carriage and Rheinmetall GmbH was the authority for the elevating mass, including the sights, and for the APU. There was a further breakdown at a more detailed level and production worksharing. The UK Royal Armament Research and Development Establishment (RARDE) was responsible for designing the HE projectile and the charge system. Germany was responsible for Smoke, Illuminating, Minelet and extended range HE, although development of the last two was not completed in the program.

The intention was for FH70 to replace M114 and equip general support battalions in German divisional artillery regiments and to equip three (two TA) British general support medium regiments replacing 5.5 inch. In the event it actually equipped UK regular regiments in direct support of infantry brigades until after the end of the Cold War.

[edit] Design

FH 70 had several interesting features including:

a vertical sliding block breach that provided obturation and held a primer magazine containing 12 primers (a similar breach was fitted to German M109G)
burst fire
an on-board 1700 cc Vokswagen engine to power hydraulics to assist bring the gun in and out of action (with hand pump back-up)and to move the gun up to 20 km at low speed without towing by an artillery tractor
electronic firing data display taking data from the otherwise conventional azimuth and elevation sights.

The barrel was 39 calibres giving 827 m/s standard maximum MV. It had a muzzle brake giving 32% efficiency.

Other conventional features included a split trail and turntable sole plate. Initially it had assisted loading but became an early user of flick-ramming. In accordance with long-standing UK practice it used one-man laying. All this meant the gun could be operated by a minimum detachment of only 4 men (commander, layer and 2 loaders). The burst fire rate was 3 rounds in 15 seconds. It was also fitted with a direct fire telescope.

[edit] Ammunition

The new projectiles conformed to the Quadrilateral Ballistics Agreement between US, UK, Germany and Italy. In essence this meant a shell with the same shape and dimensions as the US M549 rocket-assisted projectile. The standard HE shell (UK designation L15) is a thin wall design weighing 43.5 kg and containing 11.3 kg of HE.

The propellant system comprises 3 different bagged cartridges with triple-base propellant. Cartridge 1 gives charges 1 & 2, Cartridge 2 give charges 3 - 7 and Cartridge 3 is charge 8, which gives a maximum range under standard conditions of 24.7 km.

Each nation developed its own fuzes and ammunition packaging. In UK's case this led to the Unit Load Container carrying 17 complete rounds, including shells with fuzes fitted - a novelty for 155 mm.