Haubits FH77
| Haubits FH77/A | |
|---|---|
The Haubits FH77/A
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| Type | Howitzer |
| Place of origin | Sweden |
| Service history | |
| In service | 1978 - present |
| Used by |
Swedish Army Indian Army |
| Production history | |
| Designer | Bofors |
| Designed | 1978 |
| Manufacturer | Bofors |
| Produced | 1978 – 1984 |
| No. built | 720 |
| Variants | See Variants |
| Specifications | |
| Weight | 11,500 kg (25,400 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 | 9 to 14 |
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| Shell | 155 mm NATO |
| Caliber | 155 mm |
| 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°/+70° |
| Traverse | 30° left or right from centreline |
| Rate of fire | 4 rounds in 9 seconds, 6 rounds in 25 seconds, sustained 3 rpm for 20 minutes |
| Muzzle velocity | 300 to 770 m/s (980 to 2,530 ft/s) |
| Effective firing range | 21 km (13 mi) |
| Maximum firing range | 24 km (15 mi) (with base bleed-round) |
| Feed system | hydraulically powered flick rammer assisted loading |
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| Engine | Volvo B20 APU |
| Speed | 6 km/h |
Fälthaubits 77 (Swedish "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 38 calibre barrel and sliding block mechanism, and the later FH77 B export version with a 39 calibre barrel and an interrupted screw breech.
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 that the high maintenance costs, the low rate of fire and the limited 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 4 rounds in 9 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).
In order to use standard NATO ammunition, the FH77B was developed. While the sliding block worked well with the cased charges acting as a seal, it was decided that bagged charges required an interrupted screw breech. This, combined with the slightly longer barrel, resulted in a slightly improved range but also a lower rate of fire. At the same time, the petrol-fueled APU was exchanged with a diesel-fueled one, allowing it to use the same fuel as the towing vehicle.
The dedicated towing vehicle for the FH77 was the Scania SBA111 (Tgb 40). The truck was 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).
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Wikipedia