The FH-70 (acronym for Field Howitzer for the 1970s, ‘field howitzer for the 1970s’) is a 155mm towed howitzer developed with the participation of Germany, the United Kingdom and Italy. The manufacture of howitzers for these 3 countries was 212, 70 and 164 guns respectively.
It has a powerful 155mm cannon, with a maximum range of 24 km and 30 km with normal ammunition and rocket-propelled ammunition respectively. It also has an auxiliary motor (VW 2000 cm³ of gasoline, which gives it a speed of 16 km / h), enough to make small movements, short trips or to quickly get into position. The motor is necessary due to its weight.
If Great Britain was the leading country for the development of the basic version, Germany led the self-propelled version, designing the part called SP-70, mounted on the base of a turret installed in the hull of a tank, but gave problems the engine of propulsion, which together with the high cost led Germany to exit the program, which ended in 1987.
In addition to the three original partners, the weapon is also used by Japan, Saudi Arabia, and Malaysia, among others.
FH70 had several interesting features, including:
- a vertical sliding-block breech that provided obturation and held a primer magazine containing 12 primers (a similar breech was fitted to German M109G)
- burst fire
- an on-board 1700 cc Volkswagen engine to power the hydraulics and to assist bringing the gun into 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 long, giving 827 m/s standard maximum muzzle velocity. 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 that 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.
There were a number of design flaws that became apparent in service. The equipment entered full operational service in the UK in 1980. It became clear that there were significant difficulties with the tube feed system in anything but ideal conditions. 1st Regiment RHA, a unit that had conducted the Troop trials, developed their own procedures to solve these problems, related to dust contamination, and this process became established in official manuals in due course. More significantly, the trails of the gun proved to be weak at the point where maximum stress was incurred when the equipment was towed; this resulted in modification work on the UK guns in 1987. There were continual problems with the drive train on the flat-4 VW APU, and the hydraulic system was always vulnerable to the obvious problems posed by external, non-armoured, housing in combat conditions. In addition, the complex dial sight carrier was vulnerable to damage.
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. This remains the largest HE load for a standard 155mm shell.
The propellant system comprises three 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 the UK’s case, this led to the Unit Load Container carrying 17 complete rounds, including shells with fuzes fitted – a novelty for 155 mm.
Standard US pattern 155 mm ammunition can also be fired, although US primers proved problematic for the primer magazine and feed due to their variation in size.
|Mass||7,800 – 9,600 kg
(17,196 – 21,164 lbs)
|Length||Travel: 9.8 m (32 ft 2 in)|
|Barrel length||6 m (19 ft 8 in) L/39|
|Width||Travel: 2.2 m (7 ft 3 in)|
|Height||Travel: 2.5 m (8 ft 2 in)|
|Caliber||155 mm (6.1 in)|
|Carriage||Split trail, sole plate, auxiliary power unit and hydraulics|
|Elevation||-5° to +70° or -100 to +1,250 mils|
|Traverse||56°or 500 mils left and right|
|Rate of fire||Burst: 3 rounds in 15 seconds
Sustained: 3-6 rpm
|Muzzle velocity||827 m/s (2,713 ft/s)|
|Effective firing range||24 – 30 km (15 – 18 mi)
depending on ammo
- Estonia – 24
- Italian Army – 162
- Japan – 480 Built under license with the ordnance by Japan Steel Works, also used in a Japanese SPG design.
- Lebanon – Unknown number in service.
- Morocco – 30
- Netherlands – 15 in wartime reserve
- Oman – 12
- Saudi Arabia – 72
- Germany – 150 as FH155-1 (Field Howitzer 155mm Mk1). Last unit (225th Mountain Artillery Battalion) converted to tracked artillery in 2002.
- Malaysia – 15 units.
- United Kingdom – 67 (as Howitzer 155mm L121 with Ordnance 155mm L22 on Carriage 155mm L13 in TA service until 1999).