| Haubits FH77/A | |
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The Haubits FH77/A |
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| Type | Howitzer |
| Place of origin | Sweden |
| Service history | |
| In service | 1978 - 2006 |
| Used by | See Users |
| Production history | |
| Designer | Bofors |
| Designed | 1978 |
| Manufacturer | Bofors |
| Produced | 1978 - 1984 |
| Number built | 720[1] |
| Variants | See Variants |
| Specifications | |
| Weight | 11,500 kg (25,000 lb) |
| Length | Combat: 11.60 m (38 ft 1 in) |
| Barrel length | 5.89 m (19 ft 4 in) L/38 |
| Width | Combat: 9.73 m (31 ft 11 in) |
| Crew | 10 to 14 |
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| Shell | 155 mm NATO |
| Caliber | 155 mm 38 calibre |
| Action | Semi-fixed ammunition, propellant charge is contained in a plastic cartridge case with a steel head |
| Breech | Vertically sliding breech block, hydraulic ramming |
| Carriage | Split trail with castor wheels |
| Elevation | -5°/+50° |
| Traverse | 30° left or right from centerline |
| Rate of fire | 3 rounds in 8 seconds, 6 rounds in 25 seconds, sustained 3 rpm for 20 minutes |
| Muzzle velocity | 300 to 770 m/s (980 to 2,500 ft/s) |
| Effective range | 21 km (13 mi) |
| Maximum range | 27.4 km (17.0 mi) (with ERFB BB round) |
| Feed system | hydraulically powered flick rammer assisted loading |
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| Engine | Volvo B20 APU |
Haubits 77 (Field Howitzer 77 or FH77) is a Swedish 155 mm howitzer. It was developed and manufactured by Bofors. It was available in two versions, the original (sometimes referred to as Haubits 77 A) with a sliding block mechanism, and the later FH77 B export version with an interrupted screw breech.
Contents |
In the 1960s Sweden started to look for a replacement for the French Haubits F (Obusier de 155 mm Modèle 50). The American M109 howitzer was offered and tested. Though the price was low the Swedish Arms Administration found the high maintenance costs, the low rate of fire and the not so good mobility of the M109 made it worth the effort to develop a domestic howitzer.
The requirements for a new gun would be:
The result was a compromise between a more expensive Self propelled howitzer and a less mobile conventional towed howitzer.
The FH77 was the first field howitzer featuring an APU to make it self-propelled for tactical movement.
The rate of fire was, at the time, exceptionally high for a 155 mm howitzer. The FH77A (which uses semi-fixed ammunition) could fire 3 rounds in 8 seconds, or 6 rounds in 25 seconds. In a sustained firing role it could fire 6 rounds every two minutes for 20 minutes (i.e. 3 rounds per minute). The FH77B uses bagged charges and so has a lower rate of fire.
The dedicated towing vehicle for the FH77 was the Scania SBA111 (Tgb 40). The truck is equipped with a crew compartment behind the driving cab and a HIAB-crane for ammunition handling. The Howitzer's APU can be started and controlled by the driver of the towing vehicle to give an extra boost during off road driving. The maximum towing speed is 70 km/h (45 mph).
The FH77 is maneuvered by controlling the torque of the two main wheels. Speed is regulated by changing the RPM of the APU. The howitzer is deployed by spreading the trail legs, raising the castor wheels and drive the howitzer in reverse.
The FH77 is powered by a Volvo B20 Auxiliary power unit (APU). The engine is connected to three hydraulic pumps, of which, two pumps are linked to the wheels and one is used for traverse, elevation, ramming and ammunition crane.
The crew consists of 10-14 men. The minimum crew setup would be 4 men; commander, layer, loader 1 and loader 2
The FH77A uses the m/77 (42 kg) 155mm HE shell combined with a plastic casing, containing 6 increments. The FH77A could also use base bleed ammunition developed for the FH77B.