Haubits FH77

Haubits FH77/A

The Haubits FH77/A
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

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

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

Design and development

Overview

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.

Driving & Deploying

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.

APU

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.

Crew

The crew consists of 10-14 men. The minimum crew setup would be 4 men; commander, layer, loader 1 and loader 2

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 from 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.

Ammunition

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.

Variants

Users

Controversy in India

See also

References

External links