FV433 Abbot SPG

Infobox Weapon
name=FV 433 Field Artillery, Self-Propelled "Abbot"


caption=Abbot SPG at the Firepower museum in London.
origin=flagcountry|United Kingdom
type=Self-propelled artillery
is_vehicle=yes
is_UK=yes

service= 1965-1995
used_by=British Army
wars=
designer=
design_date=
manufacturer=Vickers
unit_cost=
production_date=
number=
variants=

length=(gun forward) 5.8 m
width=2.6 m
height=2.5 m
weight=16.56 t (loaded without crew)
suspension=torsion bar 5 units per side
speed=47 km/h
vehicle_range=480 km
primary_armament=105 mm L13A1 gun, 40 rounds (including 6 rounds HESH) carried
secondary_armament=7.62 mm L4A4 MG with 1,200 rounds, smoke dischargers
armour=10 and 12 mm plate
engine=Rolls-Royce K60 Mk 4G multi-fuel engine
engine_power=240 bhp @ 3750 rpm
pw_ratio=6.9lb/bhp
crew= Detachment 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 ammunition vehicle)

FV 433 Field Artillery, Self-Propelled "Abbot" is the self-propelled artillery variant of the British Army FV 430 series of armoured fighting vehicles. Using much of the chassis of the FV 430 but with a fully rotating turret at the rear housing the 105 mm gun and given the vehicle designation of FV433.

Its correct designation was "Gun Equipment 105mm L109 (Abbot)". L109 was little used, probably to avoid confusion with 155 mm M109 that entered UK service at about the same time. FV433 used a different configuration of power pack to other vehicles in the FV430 series.

Development

A completely new ammunition family, comprising shells, fuzes and cartridges, was designed for Abbot, designated 105 mm Field (105 mm Fd), was designed for Abbot's L13 ordnance. It uses electrical instead of percussion primers, and compared to US 105 mm M1 type ammunition has longer shells. The widely used US M1 type round was called "105 mm How" in UK service. 105 mm Fd came in two marks, both separate loading (shell and cartridge loaded separately). 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).

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. 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. 105 mm Fd Mk 2 is still used with L118 Light Gun.

Maximum range with 105 mm Fd Mk 1 ammunition was 15 km, Mk 2 gave 17.4 km. Maximum rate of fire was 6 - 8 rounds per minute.

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

Due to the number of charges and its compact turret Abbot did not have calibrating sights. Instead the sight mount had both Tangent Elevation (TE) and Angle of Sight Scales and 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.

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 Artillery Weapon Data Transmission System (AWDATS) installed. AWDATS displayed firing data transmitted from FACE in the battery command post via either line or radio.

The Abbot was able to swim across water, having a flotation screen fixed around the hull which was raised to provide buoyancy. The action of the tracks was sufficient to drive it forward at about 3 knots. (cf DD Tank). Each Abbot was supported by a fully amphibious Stalwart Mk 2 High Mobility Load Carrier that carried additional ammunition.

The Abbot is now obsolete, and was replaced in service by the AS-90 Self propelled gun in the mid 1990s.

Ammunition

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 simplifed dial sight and communications fit was exported to India for use in their armoured divisions. A small number were purchased by UK for use at the British Army Training Unit Suffield (BATUS) in Alberta, Canada.

Use

* British Army Royal Artillery regiments (1965-95)

*Since decommissioning from British Army service, Abbots have become popular for "Tank-driving" adventures, proving much more economical to buy and run than the genuine article.

References

*"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

See also

*List of armoured fighting vehicles
*List of artillery by country

External links

* [http://www.geocities.com/Pentagon/Quarters/7413/FV433Abbot.html FV433 Abbot and Falcon AA Vehicle]
*fr icon [http://www.armyrecognition.com/europe/Angleterre/vehicule_artillerie/Abbot/Abbot_Angleterre_description.htm Abbot at Armyrecognition.com]
* [http://www.scotlandforvisitors.com/bunkerpic2.php Abbot at Scotland's Secret Bunker]