The Abbot is a special vehicle for Britain, as it bridged the gap between Second World War-era self-propelled guns like the Sexton and modern systems like the AS-90. It had a 105 mm gun that possessed an extremely high rate of fire, capable of saturating a position with great accuracy.
The Eden Camp Museum have an Abbot (along with other famous tanks, like a Churchill, T-34 and M50 Sherman), so who better to talk about this tank than the museum’s head, Frank Wood.
It was the late 1950s and patently obvious to the British Army and its allies that there was a growing threat from Eastern Europe with a much larger Soviet mobile force that could sweep across the plains into Western Germany and in short order, once again, change the map of the region.
Remembering that the Second World War was fairly recent history, fear of regional shift was a real threat. British forces required more modern and more capable equipment.
The Allies were outnumbered, and Soviet forces were large, as had been demonstrated in WW2. A new artillery vehicle was required for upgraded defence/attack/deterrent. The Brits were still using the old-but-reliable, Canadian-built Sexton 25-pounder self-propelled gun – a version of which first saw service in 1943.
A plan was hatched to turn a Centurion into a Frankenstein’s monster by fitting it with a longer-range gun with a bigger punch to quickly upgrade existing equipment to meet the the threat of Soviet invasion. Sadly, this came to nought with only two prototypes being built.
This design failure resulted in the Fighting Vehicle Research and Development Establishment in Chertsey being given the task of designing a highly mobile self-propelled gun with a longer range and a turret with far greater flexibility, coupled with new rangefinding and communications capabilities.
The research team had to move quickly, as the British government was concerned about budgets (as always). Designing a purpose made hull for a relatively short production run would mean design delays and increased cost, so the team looked for an existing modern and reliable hull and power plant. The FV432 armoured personnel carrier fit these requirements.
The FV432 is 17 feet long and 9 feet wide and was powered by a 240 hp Rolls-Royce K60 multi-fuel engine.
Using the FV432 hull as a base for the new vehicle, a quick firing 105 mm L13A1 gun was mounted in a turret and was to be positioned towards the rear of the vehicle, while the two-stroke multifuel K60 engine was reconfigured and transmission pushed towards the front.
This new vehicle was designated Gun, Equipment, 105mm, L109 (Abbot), or FV433 Field Artillery Self Propelled Gun. Most people now call this vehicle the Abbot SPG. The Abbot moniker is kept from the British tradition that began during the Second World War of naming self-propelled artillery after religious titles, like Sexton, Priest, Bishop etc.
The Abbot was 20 feet long (gun forward), 8 ft 6 in wide and 8 ft 2 in tall with a new 360 degree turret. All in it weighed 16 tons. The Royal Ordinance Factory built the new 105mm (4.1 inch) gun with a 3.8 metre long barrel sporting a double baffle muzzle brake and a fume extractor half way along. The gun had a semi-automatic breech and the barrel had an elevation of up to 70%.
The gun was positioned inside its cradle in an unbalanced position. It is usual for guns to be balanced at the pivot point to aid elevation and depression (you can test this using a pen balanced on your finger in different positions forward or back). Due to the size and weight of the L13A1, an “equaliser” system needed to be installed to aid the gunner in depressing and elevating the gun.
A compressed air bag is used to equalise pressure in hydraulic rams at either side of the gun, the result is that the elevation wheel has the same resistance as if the gun was perfectly balanced.
To give an idea of the amount of force required to achieve this, the equaliser in the Abbot is pressurised to 875psi – car tyres are generally pressured to 32psi – so you can appreciate the sheer amount of force required.
The Abbot carried 40 rounds varying from HE, L37, L38, L45 smoke and L43 illumination shells, these shells being electrically triggered with a maximum rate of fire of 6 to 8 rounds a minute.
The Abbot has a semi automatic gearbox, where ranges are selected, for example 1-3 or 3-6 , and it will change gear automatically until top speed of around 22mph is achieved.
Innovative and highly effective in its time – the Abbot was said to be unrivalled for accuracy, firepower and range. It led to a brand new design of ammunition, comprising of shells, fuzes and cartridges which were loaded as separate components. The Abbot had a firing range of 11 miles and thus could fire over the heads of advancing infantry and accompanying tanks. It could also be used for direct fire if needs be.
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Full production of the final design began in Newcastle Upon Tyne in 1964. 234 were built, some as an ‘economy model’, which were sold to Commonwealth countries. The primary use of the Abbot was in the BAOR (British Army on the Rhine), comprised of just over 140 Abbots in service at its peak.
The barrel was said to have a life expectancy of 10,000 rounds, and the gun was well received by its crew, with reports of excellent accuracy and reliability.
The vehicle also carried a L4A4 7.62mm machine gun (an upgraded Bren gun in effect) and smoke dischargers.
There were four crew, the commander, loader and radio operator, a layer and a driver/ammunition handler. Ammunition was carried in amphibious Alvis Stalwart (nicknamed Stolly) ‘High Mobility Load Carriers’, each of which had a two man crew, making the total detachment for this vehicle 6.
Thankfully, the Abbot, in British hands, never fired a shot in anger. It and its highly trained crews were part of a successful deterrent force deployed across Germany.
The Abbot was finally retired by Britain in 1993 and was replaced by the 155 mm AS-90 gun self-propelled gun.
There are few Abbot SPGs left in Britain today but several are held in private hands including at Eden Camp Museum
The Abbot at Eden Camp Museum is registration 08EB14 and a search is on to locate her former crew – if you, or anyone you know can offer direct links to this vehicle’s history please get in touch.