Engineering:FV433 Abbot SPG

From HandWiki
FV433 105mm Field Artillery, Self-Propelled Abbot
FV433 Abbot self-propelled 105mm gun pic-010.JPG
Abbot SPG at the War and Peace show, 2010.
TypeSelf-propelled artillery
Place of originUnited Kingdom
Service history
In service1965– Present
Used byBritish Army, Indian Army
Production history
ManufacturerVickers
No. built234
Specifications
Mass16.56 t (loaded without crew)
Length(gun forward) 5.8 m (20 ft)
Width2.6 m (8 ft 6 in)
Height2.5 m (8 ft 2 in)
CrewDetachment of 6:
  • No. 1: Commander
  • No. 2: Loader & radio operator
  • No. 3: Layer
  • No. 4: Driver & Ammunition Handler
  • No. 5: Ammunition handler
  • No. 6: Second in command, and responsible for ammunition preparation.
Nos. 1–3 were turret crew, Nos. 5 and 6 travelled in the accompanying ammunition vehicle.

Armour10 and 12 mm plate
Main
armament
105 mm L13A1 gun, 40 rounds (including 6 rounds HESH) carried
Secondary
armament
  • 7.62 mm L4A4 machine gun with 1,200 rounds
  • smoke dischargers
EngineRolls-Royce K60 Mk 4G multi-fuel opposed piston engine
240 bhp (180 kW) @ 3750 rpm
Power/weight14.5bhp/tonne (10.8 kW/tonne)
Suspensiontorsion bar: 5 units per side
Operational
range
480 km (300 mi)
Speed47 km/h (29 mph)


FV433, 105mm, Field Artillery, Self-Propelled "Abbot" is the self-propelled artillery, or more specifically self-propelled gun (SPG), variant of the British Army FV430 series of armoured fighting vehicles (AFVs), using much of the chassis of the FV430 but with a fully rotating turret at the rear housing the 105 mm gun and given the vehicle designation of FV433.

Designed as a Sexton replacement, its correct designation was "Gun Equipment 105mm L109 (Abbot)"; L109 was little used, probably to avoid confusion with the 155 mm M109 howitzer that entered UK service at about the same time. The name "Abbot" continued the Second World War style of naming self-propelled artillery after ecclesiastical titles. The FV433 used a different configuration of power pack from other vehicles in the FV430 series.

Development

Abbot tank spg.jpg

Ammunition

A completely new ammunition family, comprising shells, fuzes and cartridges, was designed for Abbot's L13 gun, designated 105 mm Field (105 mm Fd). Compared to US 105 mm M1 type ammunition, it used electrical instead of percussion primers, and has longer shells. The widely used US M1 type round was called "105 mm How" in UK service. The 105 mm Fd came in two marks, both separate loading (shell and cartridge loaded separately). The 105 mm Fd Mk 1 was used initially, it had a UK-produced 105 mm How shell, mostly US pattern fuzes and reduced charge 105 mm Fd cartridges with their electrical primers (105 mm M1 uses percussion primers).

The Mark 2 adopted a new projectile design including an improved lethality HE shell (heavier with more HE) and full charge cartridges. Its shell types include HE, Smoke, Coloured Marker (Red and Orange), Illuminating, and HESH for direct fire against enemy armoured vehicles. Direct Action, Controlled Variable Time (CVT) and Mechanical Time (MT) fuzes were available for HE and Coloured Marker shells.

Initially, there were three cartridges. Sub-zones 1 and 2 were only used to provide short-range in high angle fire and were soon replaced by a plastic spoiler slipped over the shell ogive. Normal cartridge gave charges 1–5, each bag being a different colour in accordance with established UK practice, Mk 1 normal cartridge only went to charge 4. Both marks had charge Super, a single charge cartridge, although the charge was reduced in Mk 1. Charges 5 and Super used extended "bags" that projected beyond the metal cartridge case. The 105 mm Fd uses double (often internationally called triple) base propellants designated N in UK service instead of the single based FNH propellants favoured by the US. The 105 mm Fd Mk 2 is still used with L118 Light Gun.

Gun

Maximum range with 105 mm Fd Mk 1 ammunition was 15 km, the Mk 2 gave 17.4 km. Maximum rate of fire was 6–8 rounds per minute with 40 rounds carried in the vehicle.

The gun was able to elevate to 70 degrees and depress to -5 degrees, sufficient to engage enemy AFVs if necessary. Traverse and shell ramming were powered by electrical servo mechanisms, elevation and cartridge ramming were by hand.

Due to the number of charges and its compact turret, the Abbot did not have calibrating sights. Instead, the sight mount had both Tangent Elevation (TE) and Angle of Sight Scales with a separate Gun Rule to convert range into TE, corrected for the muzzle velocity variation from standard. The dial sight had all scales internal, illuminated and viewed through a single eyepiece.

Communications

The Abbot was fitted with both line and radio Larkspur B48, then Clansman UK/PRC 352) communications to its battery command post, which used the Apparatus Loud Speaking No. 23, this enabled the gun No. 1 to acknowledge his fire orders merely by clicking his pressel switch. Initially, it also used induction loop communications for the turret and external crew.

Shortly after the Field Artillery Computer Equipment (FACE) entered service in the early 1970s, the Gun Rule was removed and the Artillery Weapon Data Transmission System (AWDATS) installed. AWDATS displayed firing data transmitted from FACE in the battery command post via line or radio.

Mobility

The Abbot was able to swim across water, using a flotation screen fixed around the hull, raised to provide buoyancy. The action of the tracks was sufficient to drive it forward at about 3 knots (5.6 km/h) (see also DD Tank). Each Abbot was supported by an amphibious Stalwart High Mobility Load Carrier with additional ammunition.

Service history

British Army Abbots were replaced by the AS-90 self-propelled gun in the mid-1990s. It was in service with the Indian Army, now replaced by the K9 Thunder self-propelled howitzer.[1] No sources refer to Abbots ever being used in combat.

Ammunition

HESH, L43A2, L37A2, L31A1, L36
105mm Field Mark 1
  • L32 Cartridge 105mm Field, Normal (Charges 1–4)
  • L34 Cartridge 105mm Field, (Charge Super)
  • L33 Shell 105mm Howitzer, HE
  • L32 Shell 105mm Howitzer, WP
  • L51 Shell 105mm Howitzer, Smoke
  • L55 Shell 105mm Howitzer, Illuminating
  • L43 Shell 105mm Howitzer, HESH
  • L44 Shell 105mm Howitzer, Practice
105mm Field Mark 2
  • L35 Cartridge 105mm Field, Normal (Charges 1–5)
  • L36 Cartridge 105mm Field, Super
  • L31 Shell 105mm Field, HE
  • L36 Shell 105mm Field, Smoke
  • L37 Shell 105mm Field, Marker, Red
  • L38 Shell 105mm Field, Marker, Orange
  • L34 Shell 105mm Field, Illuminating
  • L42 Shell 105mm Field, HESH
  • L41 Shell 105mm Field, Practice

Variants

A simplified Value Engineered Abbot without flotation screen, NBC defence equipment, power traverse, elevation or loading, a simplified dial sight and communications fit was exported to India. A small number were purchased by the UK for use at the British Army Training Unit Suffield (BATUS) in Alberta, Canada.

A SPAAG version using an unmodified chassis with an alternate turret mounting two 30 millimetres (1.2 in) HSS 831L cannons was prototyped as the "Falcon" but limited ammunition capacity of only 310 rounds per gun led to its cancellation.

The Abbot's L13 105mm gun has been reproduced as a towed howitzer on a new carriage for the Indian Army.[2]

Operators

  • British Army - 146 received for use by Royal Artillery regiments (1965–1995)
  • Indian Army - 80 currently in service in the Regiment of Artillery (including 68 Value Engineered Abbots received in the 1960s)

See also

References

Sources

  • The Abbot Self-propelled Gun, Interavia International Defense Review, No 12/1965
  • User Handbook for Gun, SP, 105mm Fd, Abbot (FV433), Army Code 14311, 1965
  • Credits to Andrew Dickinson and David Gibbons.

External links