FH-70
Encyclopedia
The FH-70 is a towed howitzer
in use with several nations.
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 authorities 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 Territorial Army (TA)) British general support medium regiments replacing the 5.5 inch gun
. In the event it actually equipped UK regular regiments in direct support of infantry brigades until after the end of the Cold War
, and only replaced the L118 Light Gun
in two TA regiments, 100th (Yeomanry) Regiment Royal Artillery
and 101st (Northumbrian) Regiment Royal Artillery (Volunteers)
from 1992 to 1999.
The barrel was 39 calibre
s long 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.
There were a number of design flaws that became apparent in service. The equipment entered full operational service in the UK in 1980, and it became clear that there were significant difficulties with the tube feed system in anything but ideal conditions. 1st Regiment RHA, a unit who had conducted the Troop trials, evolved their own procedures to cure the problems, which 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 stresses incurred when the equipment was towed. and 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 hosing, in combat conditions. In addition, the complex dial sight carrier was vulnerable to damage.
By the mid-1990s, the gun, in the UK, was being superseded by events, and more modern equipments. The writer of this section, who worked the equipment for a number of years, considers the gun to have been a design compromise - properly fought, with an experienced detachment, and with ready repair facilities to hand, the equipment was calpable of high-speed rates of fire, surprising degrees of mobility in deployment - including being air-portable under a CH-47 Chinook - and could be brought into action and worked with as few as a single crewman. Against that, it was quite clear that the gun suffered from the interface between the different nations and manufacturers involved in production. One could conclude that the equipment was a useful demonstration of the final throes of towed medium artillery.
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 fuses 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.
Standard US pattern 155mm ammunition can also be fired, although US primers proved problematic for the primer magazine and feed due to their variation in size.
. Also used in a Japanese design SPG) - 30 - 15 - 12 - 12 - 67 (as Howitzer 155mm L121 with Ordnance 155mm L22 on Carriage 155mm L13 (in TA service until 1999)) - 72+
Howitzer
A howitzer is a type of artillery piece characterized by a relatively short barrel and the use of comparatively small propellant charges to propel projectiles at relatively high trajectories, with a steep angle of descent...
in use with several nations.
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 agreement 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 authorities had overall responsibility for R & D, and Vickers Ltd
Vickers
Vickers was a famous name in British engineering that existed through many companies from 1828 until 1999.-Early history:Vickers was formed in Sheffield as a steel foundry by the miller Edward Vickers and his father-in-law George Naylor in 1828. Naylor was a partner in the foundry Naylor &...
was the co-ordinating design authority. They were also the design authority for the carriage and Rheinmetall
Rheinmetall
Rheinmetall AG is a German automotive and defence company with factories in Düsseldorf, Kassel and Unterlüß. The company has a long tradition of making guns and artillery pieces...
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
M114 155 mm howitzer
The M114 155 mm howitzer was a towed howitzer used by the United States Army. It was first produced in 1942 as a medium artillery piece under the designation of 155 mm Howitzer M1. It saw service with the US Army during World War II, the Korean War, and the Vietnam War, before being...
and equip general support battalions in German divisional artillery regiments and to equip three (two Territorial Army (TA)) British general support medium regiments replacing the 5.5 inch gun
BL 5.5 inch Medium Gun
The BL 5.5 inch Gun was a British artillery gun introduced during the middle of the Second World War to equip medium batteries.-History:In January 1939 a specification was issued for a gun to replace the 6 inch 26 cwt howitzers in use with most medium batteries...
. In the event it actually equipped UK regular regiments in direct support of infantry brigades until after the end of the Cold War
Cold War
The Cold War was the continuing state from roughly 1946 to 1991 of political conflict, military tension, proxy wars, and economic competition between the Communist World—primarily the Soviet Union and its satellite states and allies—and the powers of the Western world, primarily the United States...
, and only replaced the L118 Light Gun
L118 Light Gun
The L118 Light Gun is a 105 mm towed howitzer, originally produced for the British Army in the 1970s and widely exported since, including to the United States, where a modified version is known as the M119A1...
in two TA regiments, 100th (Yeomanry) Regiment Royal Artillery
100th (Yeomanry) Regiment Royal Artillery
100th Regiment Royal Artillery is a British Territorial Army Royal Artillery regiment that has three gun batteries, all equipped with the L118 Light Gun.- The Batteries are :...
and 101st (Northumbrian) Regiment Royal Artillery (Volunteers)
101st (Northumbrian) Regiment Royal Artillery (Volunteers)
101st Regiment Royal Artillery are a M270 Multiple Launch Rocket System and Surveillance and Target Acquisition regiment of the Territorial Army with sub units throughout Northumbria. It is the only unit of the Territorial Army equipped with MLRS.The Regiment's role is to provide...
from 1992 to 1999.
Design
FH 70 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 VolkswagenVolkswagenVolkswagen is a German automobile manufacturer and is the original and biggest-selling marque of the Volkswagen Group, which now also owns the Audi, Bentley, Bugatti, Lamborghini, SEAT, and Škoda marques and the truck manufacturer Scania.Volkswagen means "people's car" in German, where it is...
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 tractorArtillery tractorArtillery tractor is a kind of tractor, also referred to as a gun tractor, a vehicle used to tow artillery pieces of varying weights.-Traction:... - electronic firing data display taking data from the otherwise conventional azimuth and elevation sights.
The barrel was 39 calibre
Caliber (artillery)
In artillery, caliber or calibredifference in British English and American English spelling is the internal diameter of a gun barrel, or by extension a relative measure of the length....
s long 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.
There were a number of design flaws that became apparent in service. The equipment entered full operational service in the UK in 1980, and it became clear that there were significant difficulties with the tube feed system in anything but ideal conditions. 1st Regiment RHA, a unit who had conducted the Troop trials, evolved their own procedures to cure the problems, which 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 stresses incurred when the equipment was towed. and 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 hosing, in combat conditions. In addition, the complex dial sight carrier was vulnerable to damage.
By the mid-1990s, the gun, in the UK, was being superseded by events, and more modern equipments. The writer of this section, who worked the equipment for a number of years, considers the gun to have been a design compromise - properly fought, with an experienced detachment, and with ready repair facilities to hand, the equipment was calpable of high-speed rates of fire, surprising degrees of mobility in deployment - including being air-portable under a CH-47 Chinook - and could be brought into action and worked with as few as a single crewman. Against that, it was quite clear that the gun suffered from the interface between the different nations and manufacturers involved in production. One could conclude that the equipment was a useful demonstration of the final throes of towed medium artillery.
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. This remains the largest HE load for a standard 155mm shell.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 fuses 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.
Standard US pattern 155mm ammunition can also be fired, although US primers proved problematic for the primer magazine and feed due to their variation in size.
Operators
- 24 - 184 as FH155-1 (Field Howitzer 155mm Mk1). Last unit (225th Mountain Artillery Battalion) converted to tracked artillery in 2002 - 162 - 480 (built under license with the ordnance by Japan Steel WorksJapan Steel Works
is a steel manufacturer founded in Muroran, Hokkaidō, Japan in 1907.-History:Japan Steel Works was set up with investment from British firms Vickers and Armstrong Whitworth. During World War II, they manufactured what was then the world's largest gun barrel to be fitted on the battleship Yamato...
. Also used in a Japanese design SPG) - 30 - 15 - 12 - 12 - 67 (as Howitzer 155mm L121 with Ordnance 155mm L22 on Carriage 155mm L13 (in TA service until 1999)) - 72+