Haubits FH77/A
From Wikipedia, the free encyclopedia
Haubits 77 (Field Howitzer 77 or FH77), sometimes referred to as Haubits 77A (FH 77A), is a Swedish 155 mm howitzer. It was developed and manufactured by Bofors.
Contents |
[edit] Development
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:
- High mobility.
- High momentary rate of fire.
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 FH77 could fire 3 rounds in 8 seconds, or 6 rounds in 25 seconds. In a sustained firing role it could fire 6 rounds every second minute for 20 minutes.
[edit] Specification
- Era: Modern
- Name: 15,5 cm Haubits 77
- Type: Howitzer
- Nation: Sweden
- Manufacturer: Bofors
- Target: General
- Date: 1978
- Production Date: 1978 - 1984
- Service Date: 1978 -
- Numbers Built: 206
- Operators: Sweden
- Breech: Vertically sliding breech block, hydraulic ramming
- Barrel: 38 cal (5,890 mm)
- Elevation: -5 to +50°
- Traverse: ±30°
- Caliber: 155×787 mm
- Carriage: Split trail with castor wheels
- Weight: 11,500 kg
- Length: 11.6 m
- Shell Types: Se below
- Action: Semi-fixed ammunition, propellant charge is contained in a plastic cartridge case with a steel head.
- Muzzle velocity: 300 - 770 m/s
- Tactical range: 21 km (24 km with base bleed)
- Maximum range: 24 km
- Rate of Fire: 3 rounds in 8 seconds or 6 rounds in 25 seconds, sustained fire 6 rounds every second minute for 20 minutes
- Crew: 2
- Transportation: Self deployable with APU and towed using Scania SBAT
- Miscellaneous: Perforated muzzle brake
[edit] Ammunition
The FH77 uses the m/77 155mm HE shell combined with a plastic casing, containing 6 increments. The FH77 could also use base bleed ammunition developed for the FH77B.
[edit] APU
The FH77 is powered by a Volvo B20 petrol engine. The engine is connected to three hydraulic pumps. Two pumps are linked to the wheels and one is used for traverse, elevation, ramming and ammunition crane.
[edit] Crew
The crew consists of 10-14 men. The minimum crew setup would be 5 men; commander, layer, loader 1, loader 2 and loader 3.
- The commander direct all the activity of the crew from a platform to the left of the gunlayer.
- The layer sits on the left hand side of the gun, operating the fire control computer and driving the howitzer when in self deployment mode.
- Loader 1 is located to the right hand side of the gun and is in charge of supplying the shells form the loading table in front of him.
- Loader 2 and 3 would be working on the ground, providing shells to loader 1 by means of a hydraulic crane and loading cases in the loading trough.
[edit] Driving & Deploying
The dedicated towing vehicle for the FH77 was the Scania SBAT111 (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.
[edit] See also
- Kustartilleripjäs 12/80
- Haubits 77B
