Two decades on one page, the start of the story.

The Fifties – Saladin and Saracen

Reconnaissance and Light Armour

By the close of WWII Germany remained convinced that wheeled vehicles were best for reconnaissance tasks, while the US preferred tracks. The British Army rejected further development of the two axle Coventry armoured vehicle and retained in service the Daimler MkII and AEC Mk III until a new vehicle could be introduced.

With this in mind, work started on defining a requirement for a high mobility wheeled fighting vehicle design that could operate in all environments and offer a high degree of commonality between variants. With wartime pressures to maximise production from different manufacturers gone the demand for standardisation and a reduction of vehicle types was a key requirement of the Ministry of Supply. Indeed, the lack of commonality across components and standards in such seemingly mundane items as screw threads had resulted in large quantities of equipment being abandoned in North Africa between 1941 and 1942. American sources estimated this lack of standard threads alone added £25m to the cost of war.

The General Staff specification was issued in 1946 for what would become Saracen and Saladin

One of the first issues to resolve was the number of axles; a two-axle design was discounted because of mobility and weight carrying concerns, and an eight-wheel design discounted because of the weight and complexity. A 6×6 design was ultimately thought to be the best compromise. The US T19 (based on the T18E1), the T28 and T66 were all examined and generally considered to be a good series of general design concepts to emulate, especially the T28 with its independent suspension, although there is no direct link.

The requirement envisaged a 3 or 4 man crew, 6×6 vehicle armed with an improved version of the 39mm 2 Pounder. Weight rose slightly during later versions of the requirement, creating an opportunity for using an emerging concept in standardised military engines; the Rolls Royce B series. This standardised engine series design also meant the elimination of different thread types and the resultant need for two sets of tools and fastenings. High reverse speed, ease of servicing, mobility and vision were also key elements of the requirement.

Protection was defined as the ability to withstand 7.93mm Armour Piercing from all angles, 25 Pounder (equivalent) shell splinters at 9m and a 9kg mine under any wheel, close to Level IIIa in today’s standard, STANAG 4569.

The image below shows an early wooden mock-up, produced by the newly renamed Fighting Vehicle Research and Development Establishment (FVRDE)

A contract was placed with Alvis in 1947 for the production of two prototypes of the FV601, one of which was sub-contracted to Crossley Motor.

In a foreshadowing of more recent defence development work, doubts about the specification began to set in almost as soon as Alvis had started work, specifically in relation to the main armament. After much back and forth the decision was made for the Armaments Design Establishment (ADE) to develop a brand new gun specifically for the vehicle; the 76mm L5A1. This larger gun displaced the third crew member from the earlier turret design. Other requirement changes resulted in modifications to the turret layout, along with more delays.


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During the development phase, Saracen was prioritised over Saladin in order to provide protected mobility vehicles for Malaya.

By the mid-fifties Malaya had been stabilised to a point where the large numbers of Saracens originally envisaged were no longer required and the focus shifted back to Saladin. Production of the Saracen was then slowed to allow export production orders to catch up.

It wasn’t until 1958 that the FV601 Saladin Mk2 entered production, 13 years after the initial requirement was defined and the design work had started.

Production of Saladin ran from 1958 to 1972, with 1,177 built.

Protected Mobility

Two other vehicles were originally envisaged as part of the FV600 series; the FV602 Command Post and the FV603 Armoured Personnel Carrier. Both were thoroughly modern concepts for the time, but the vehicle design limited the practicality of the Command Post variant and it was soon dropped, although other command post variants would appear later.

The FV603 was entirely a different matter.

In 1948 a state of emergency was declared in Malaya and by 1950 plans were being formulated by Lt Gen Harold Briggs to direct the anti-communist campaign. This evolved into a concerted anti-terrorist campaign that would have no need for tanks or artillery. The battles would instead be fought in terrain that favoured the ambush. Therefore, dismounted infantry – supported by small armoured cars – was the preferred option. Something more substantial than a truck would also be needed to provide some measure of protected mobility to the infantry.

Step forward the FV603 Saracen.

Despite still being in development it was thought to be an ideal vehicle. Saracen was designed to be no wider than 8ft (2.45m) so as to fit between the rows of rubber trees on Malayan plantations, a key specification that would be carried through to CVR(T). Development of Saracen was therefore prioritised over Saladin.

The first delivery of the prototype was made in June 1951, with two delivered directly to Malaya for field trials in the actual field it would be used in! Testing revealed a number of problems, but for the most part, these were resolved in subsequent iterations before large-scale production commenced.

In 1952 the FVRDE issued a production specification that comprised a number of sub-variants; FV603a Personnel and Load Carrier, FV603b Regimental Command Vehicle, FV603c ASSU ‘Tentacle’ or signals, FV603d Armoured Ambulance, FV603e Royal Artillery Radar Vehicle, FV603f Royal Artillery Sonic Detection Vehicle, and the FV603g Infantry Command Post.

The first production order was for 250 of the FV603a variant, later designated Personnel Carrier Mk1, shown below in Coventry and Malaya.

The Alvis team returned to Malaya in 1953 to continue testing and evaluation. Later Mk2 versions would incorporate the experience captured in Malaya, much of it do with operations in hot weather. If the hot weather was problematical, cold weather was not. The trials vehicles were tested in Canada at -37 degrees Celsius with no problems.


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Although Saracen always suffered from having a distinct transmission whine, it was highly mobile and could keep moving even with two wheels blown off (as long as they were on different sides). The two front steering axles also provided excellent manoeuvrability.

In some ways, there are similarities between both Saracen and the more recent Mastiff; both vehicles were required to provide protected mobility in a counter-insurgency campaign where existing Army vehicles were totally unsuited, and both vehicles were obtained with as much haste as possible once the procurement decision had been made.

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The Sixties

Although Saracen was highly mobile, it could not keep up with Main Battle Tanks, and so a tracked armoured personnel carrier was required as the post-war focus of the British Army became ever more the defence of Western Europe against the Warsaw Pact.


We can reasonably trace the FV432’s roots to a number of post-war vehicle developments such as the Oxford Carrier and FV401 Cambridge Carrier, however, the direct forerunner of the FV432 is the FV420 series of vehicles, developed in the late fifties.

FV421 and FV401

The FV420 vehicle family was to comprise; FV421 Load Carrier, FV422 Armoured Personnel Carrier, FV423 Command Vehicle, FV424 Royal Engineers Section Vehicle, FV425 Royal Electrical and Mechanical Engineers Section Vehicle and the FV426 Orange William Anti-Tank Guided Weapon Vehicle, although only a small number were built.

Using experience from the FV420, the FV431 Load Carrier was the first of the family. It had an armoured front section with the ability to carry a 3-tonne payload.

Both it and the prototype FV432 were built by Sankey in 1962.

Following troop trials, the first production FV432 vehicles entered service in 1963 and by the end of the production run in 1971 over 3,000 vehicles had entered service with the British Army.

It is a simple and adaptable vehicle, a basic armoured box of welded steel construction to provide protection against automatic weapons and shell splinters. The FV430 series of vehicles has progressed through several marks and many variants although it was never given a formal name. The original suggestion of Trojan was dropped after objections from the Trojan car company.

The 432 would also be used for many tasks and have role-specific equipment, WOMBAT carrier, ground surveillance, command, mortar, ambulance, recovery, Carl Gustav, Barmine layer, Milan, sonic detection, a 30mm RARDEN Fox turret and even to provide OPFOR vehicles. Other variants (over the years) included the FV433 Abbot Self Propelled Gun, FV434 Carrier Maintenance, FV436 Mortar Locating Radar, FV437 Pathfinder (with snorkel), FV438 Swingfire Launcher and FV439 Communications.


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[tab title=”FV433 Abbot and FV434 Carrier Maintenance”]

FV433 Series 1


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FV433 Series 2


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FV438 Swingfire



It is still in service in 2017 – some 60 odd years after it was first introduced – and is likely to continue to be so for some time still to come.

Lightweight High Mobility Tactical Vehicle

The story of CVR(T) and therefore Ajax, can trace some lineage back to a series of studies and concepts from the late fifties and early sixties.

FVRDE developed a number of concepts – both wheeled and tracked – including the Lightweight High Mobility Tactical Vehicle (LHMTV) concept for a vehicle that could be transported by air.

The LHMTV vehicle family was to be constrained by the payload capacity and internal dimensions of the Armstrong Whitworth Argosy transport aircraft. The Argosy’s payload capacity was very low compared to today’s standards, at just 4.5 tons.

RAF Argosy Transport Aircraft

In addition to Argosy transport, LHMTV also envisaged a ‘stripped down’ configuration (3.6 tons) that could be sling-loaded by helicopter for use in the amphibious assault role. Other requirements included a maximum width of 7ft and an ability to traverse wet gaps with only minimal preparation.


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Although there was some interest from the British Army, it was thought for the vehicle to be of use in Europe, more protection would be needed.

Armoured Vehicle Reconnaissance (AVR)

Another project of note was Stuart and Chaffee replacement projects during WWII; the A46. Although this project did not progress, it was re-invigorated post-war with the FV300 series of vehicle concepts.

The FV300 series included FV301 – Light Tank, FV302 – Command Post, FV303 – 20 pounder SP Gun, FV304 – 25 pounder SP Gun, FV305 – 5.5in SP Gun, FV306 – Light ARV, FV307 – Radar Vehicle, FV308 – Field Artillery Tractor, FV309 – Ammunition Vehicle, FV310 – Light APC and FV311 – Armoured Load Carrier.

Despite a number of mock-ups and prototypes being produced, the project was cancelled in the early fifties, although some aspects of the design did endure in CVR(T). And even though Saladin had only entered service a few years prior in 1960, the Army stated a desire to replace it with a new design defined by General Staff Requirement (GSR) 1106.

The vehicle was to be called the Armoured Vehicle Reconnaissance (AVR).

Both wheeled and tracked concepts were developed by the (FVRDE) and presented to the Army in 1960. These early designs eschewed the combined gun/missile launcher being developed for the US Armoured Reconnaissance/Airborne Assault Vehicle (M551 Sheridan). Instead, it proposed a 3 man tracked design that weighed just under 14 tonnes, mounting a 76mm or 105mm gun with additional box launchers for the Swingfire Anti-Tank Guided Weapon (ATGW). The turret arrangement was its most unusual feature, being both limited in traverse to just 180 degrees and containing the vehicle’s driver.

The wheeled concepts drew on a much larger 20-tonne test vehicle called the TV1000 (powered by a Rover Meteorite V8 petrol engine rated at 535 bhp).

Work continued on concepts; AVR was to be a family of vehicles comprising four basic types, Fire Support, Anti-Tank, Anti APC and Liaison.  A fifth type, Armoured Personnel Carrier, was to be used for troop transport, command and medical evacuation. All were to be used in Europe and for future airborne forces.

Combat Vehicle Reconnaissance (CVR)

By 1963 the Armoured Vehicle Reconnaissance (AVR) project had been supplanted by the recognition that a more versatile family of vehicles was needed and that the AVR baseline vehicle was unsuitable.

Between 1963 and 1965, work on these new concepts progressed.

A separate study completed by the Concepts Section of the FVRDE resulted in a proposal for a family of light tracked vehicles that included one with a 120mm Recoilless Rifle and another with a turreted 76mm gun. One of the more interesting concepts saw the same vehicle mounting a 105mm howitzer that could be dismounted and fired independently of the carrier; echoes of the much later gun portee designs using the M777 155mm.

The new gun was planned to replace the 105mm Pack Howitzer with an ability to fire mounted or dismounted. When mounted, recoil forces would be transmitted to the ground via extendable spades rather than stressing the lightweight chassis. When dismounted, it was envisaged the vehicle would be used to ferry ammunition from stores locations to the firing point.

These were evolutions of the LHMTV described above, showing the 4 wheel configuration.

There was a great deal of work conducted during these years with many compromises, discussion and concept development, especially in evaluating the merits of the various wheeled and tracked designs, engine layout and requirements such as different protection levels.

Throughout this process, an extra wheel was added.

General Staff Requirement (GSR) 3301 was issued in August 1964 for the Combat Vehicle Reconnaissance (CVR).

CVR was to focus on mobility, both on the battlefield and – crucially – getting to the battlefield. Unlike Saladin and Saracen, CVR was required to be both air droppable and air transportable to support rapid deployments. Weight limits were aligned with the carrying capacity of the proposed Hawker Siddeley HS681 STOL (later STOVL) transport aircraft, with two vehicles carried on a single aircraft. Given the gradual shift that was taking place at the time away from static overseas garrisons and towards an ability to respond rapidly from European bases, this requirement made perfect sense in the political context of the moment.


HS681 was subsequently cancelled so this requirement changed to the C130 Hercules.

A maximum width of 2.1 metres was specified so that CVR could move freely between rubber trees in plantations in Malaya, and negotiate narrow tracks (this is the same width as the modern US HUMVEE.)


A short time after proposing their family of fighting vehicles, the FVRDE then produced the TV 15000 test vehicle. TV 15000 would become the precursor to CVR(T) and featured a range of new innovations such as aluminium armour, something which had never been used on a British armoured vehicle before. It’s hydropneumatic suspension and lightweight tracks were also at the cutting edge.

In parallel to this work by FVRDE, the Government also entered into a fruitless agreement with the USA, Canada and Australia to explore concepts for a light reconnaissance vehicle with the detailed design work being carried out by FMC in the USA.

Meanwhile, work on TV15000 had continued and by the end of 1966 FVRDE had produced two test rigs, one static and one mobile, with the mobile test rig rolled out of the workshops on Christmas Eve 1965, shown in the image below


TV15000 on its first trip out of the workshops

The Test Rigs were intended specifically to prove the automotive components: engine, transmission, track and suspension. The TN-15 transmission was a scaled down variant of the Self Changing Gears Ltd Merritt Wilson TN12 as used in the Chieftain. This system was so far ahead of its time that the designer of the revolutionary proportional rate steering system reputedly had a nervous breakdown trying to figure out how he had made it work!

The original hydropneumatic suspension of the TV 15000 was eventually replaced with a more conventional torsion bar design and the Rolls Royce Vanden Plas B.60 engine swapped for a new version of the 4.2 Litre Jaguar XK . The petrol engine was de-rated to 195 bhp in order to allow it to use low octane fuel, and this produced a power to weight ratio of approximately 26 bhp/tonne, delivering a range of 600km.

Mobile Test Rig 01SP66

A year later (they did not mess around in those days) Alvis were awarded a contract to produce 17 CVR(T) prototypes from the Mobile Test Rig design and test studies.

The first prototype was rolled out of the Alvis factory on January 23rd, 1969 and trials would commence soon after.

CVR(T) Prototypes

30 prototypes were eventually built, 17 Scorpions and the balance across the other variants.

Steering geometry and track width-to-length ratios determined the hull width. In order to squeeze the driver in while wearing winter combat gear the resultant engine compartment width meant the final engine choice was limited. The Jaguar XK was the only suitable off-the-shelf engine that would both fit and provide sufficient power. The end result was a very compact and mobile vehicle with a weight of just under eight tonnes and a ground pressure of less than 0.35 kg/cm2.

Its height was less than 2.1m, not much different to a Land Rover.


Meanwhile, the wheeled variant of the CVR programme was in development to GSR 3358, issued in 1965.

The British Army had long made use of wheeled armoured cars in the reconnaissance role, the FV700 Ferret and FV600 Saladin being two good examples. FVRDE proposed the Ferret Mark V and Ferret Mark VI, the former having a one-man turret and the latter, a two-man turret armed with a 30mm RARDEN cannon as fitted on Scimitar. The FV721 Combat Vehicle Reconnaissance (Wheeled) or CVR (W) Fox was developed further by Daimler under a separate development contract and by 1967 the first prototype was delivered.

By April 1969, all 15 prototype vehicles had been delivered ready for user acceptance trials.

CVR(W) Prototype (left) and Early Production Vehicle (right)

CVR(W) Prototype (left) and Early Production Vehicle (right)

Fox was an obvious development of the Mk IV ‘Big Wheel Ferret’. It also had the same Jaguar engine as found in CVR(T), echoing the commonality across vehicles types previously exhibited by Saracen and Saladin.

High Mobility Load Carriage

To carry the theme of commonality forward, and ignoring the Salamander fire tender, a look at the Stalwart.

In the early fifties, the British Army was considering operations to support an increasingly armoured force in Germany. It was thought that in any future European conflict the Warsaw Pact would destroy all river bridges as a matter of course, and given the many rivers in the area there was a choice to be made; either to dramatically improve Royal Engineer bridging capacities or, to consider amphibious supply vehicles.

A version of the FV432 was evaluated, but wheels had many advantages for the supply role and so in 1957 Alvis put forward the idea of an amphibious load carrier based on the Salamander hull, and put their money where their mouth was by developing the Prototype High Mobility Load Vehicle by 1959.

From this first prototype, and perhaps a bit of the ‘Old boy’s network’ in defining a demand, an official requirement was issued in 1960 that included a 5-ton payload, superior off-road performance to Saracen/Saladin and the ability to cross rivers and other watercourses unaided.

A second prototype was developed that incorporated a great many changes in order to meet the ‘official’ requirement.

A number of additional prototypes continued the development effort, including evaluations by both the British Army and Swedish Navy (for shore battery resupply). This incremental improvement the incorporation of user feedback resulted in 1962, when the British Army ordered 125, to be designated the FV620, named Stalwart. Again, additional fine-tuning took place as the vehicles entered service and in 1964, another 325 were ordered.

A Mk2 version (FV622) had improved visibility, driver layout, self-recovery winch and modifications to improve air carriage.

Additional variants of the Mk2 included REME (FV624) vehicles, gun limber (FV623), Unit Bulk Refuelling Equipment (UBRE) and even a proposal for a Swingfire launcher.


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Just under 800 Stalwarts of various types were received by the British Army.


The end of WWII, Churchill’s Cold War speech, the 1957 Defence Review, the birth of NATO, transformation from Empire to Commonwealth and the Suez reality check were hugely significant events in the British Army’s vehicle requirements. The wartime need of getting any vehicles possible into service was no longer a factor, standardisation leading to reduced support costs was a priority.

This demand for standardisation led to the Rolls Royce B series engine and two vehicles built around it, Saladin and Saracen.

Vehicles also had to be suitable for major war roles and use in limited wars.

Despite changing requirements leading to development delays, Saladin entered service towards the end of the decade. The campaign in Malaya produced an urgent operational requirement for protected mobility and so development and production of Saracen was prioritised over Saladin, the vehicle entering service in the mid-fifties.

Production and use of both would continue into the next decade, with a number of additional variants and modification packages developed and introduced, but by the beginning of the sixties, thoughts of replacement were already well advanced.

What is interesting to note is that both were not used together in what we might consider a medium weight formation, instead, Saladin’s were employed with Ferret armoured cars in Armoured Car Regiments, and Saracens’ separately in a number of other formations, although Saracen’s were attached to Armoured Car Regiments for Pioneers and other support personnel.

However, by the end of the fifties, the British Army had achieved its objective of bringing into service a family of vehicles built around a common set of components and that were perfectly suited to their diverse operating environments and requirements.

Although FV432 was in service in Germany from the early sixties, Saracen and Saladin continued to be used in Aden, Libya, Borneo and other overseas locations, proving its blend of firepower and mobility was relevant then as it was when conceived in the late forties.

Mines were a particular problem in Aden during the sixties and a number of vehicle modifications introduced to deal with them. Protected mobility would go on to be a significant issue in the development of FRES, especially regarding IED protection.

Although they were not used for route clearing it is interesting to note that for operations in Aden during the late sixties a number of ‘mine protected’ vehicles were developed and deployed to good effect. Specifically, these were modifications for Land Rovers and 3 Ton Trucks.


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As the sixties rolled on, the FV432 came into widespread service with the British Army and thoughts were turning to its replacement. Alongside this initial work that would lead to Warrior, the replacement for Saladin and Saracen also progressed through various projects and concept studies until CVR(T) and CVR(W) towards the end of the decade.

What characterised both Saladin/Saracen/Stalwart/Salamander and CVR(T)/CVR(W) was commonality.

Commonality at a component level, engines, transmission and controls etc., but also designs as a whole.

Were any of them a medium weight capability?

Although the modern concept of medium weight intervention forces looks very different to those of the sixties and seventies, the deployability versus protection debate resulted in vehicles that prioritised mobility over protection.

Above all though, the major take away from the Saladin and CVR(T) families and their underpinning concept of operations, was that commonality was a serious consideration enabled by two simple factors.

One, there was no choice in a post-war environment, costs had to be reduced.

Two, the ability to take a systems view was only possible because design authority and concept generation rested with the publically owned ‘establishments’

In the next section, CVR(T) and CVR(W) come into service, work starts on an FV432 replacement, and not forgetting, Saxon.

British Army Medium Weight Capability – Table of Contents

Introduction and Notes

What this document is, sources and acknowledgements, and what this document is not

The Fifties and Sixties

Saladin and Saracen enter service, early work on their replacement commences and completes. The FV432 enters service, and the BMP-1 does likewise, work on Warrior gains pace.

The Seventies

CVR(T) and CVR(W) enter service, and the rapid deployment concept cuts its teeth with the C-130

The Eighties

CVR(T) continues to be developed and sees action in in the Falkland Islands and Warrior enters service. Oh, and Saxon.

The Nineties

A decade of major change; the end of the Cold War, operations in the Gulf and the Balkans. The microprocessor and communications revolution. VERDI, FFLAV, WASAD and the rise of the acronym in defence. ASCOD, CV90 and others developed. Protected mobility becomes a requirement, again, and finally, interesting materials development make an appearance in the defence vehicle world.

TRACER, MRAV and Project Bushranger

Three vehicle development projects that would have importance to the ongoing story of developing a medium weight capability.

Turning Points in the Balkans

Important milestones in the development of medium weight capabilities, a trip across the Sava and WWIII averted at an airport.

Change Comes to US and UK Forces

The Future Combat System, the UK follows suit, FRES and being a force for good.

FRES Gets into Gear but Iraq Looms Large

2001 to 2004, TRACER and MRAV continue but the new kid on the block called FRES is starting to take over whilst the shadow of Iraq falls on the project.

Snatch and the Trials of Truth

Between 2005 and 2007 the Army experienced significant change. FRES picked up speed but operations in Iraq overshadowed the medium weight concept.

FRES Changes Names and Changes Lane

2008 to 2009, it becomes increasingly difficult to balance the needs of operations with the desire to transform and bring FRES to fruition at the same time.

FRES Scout to the End of FRES

2010 to 2011, putting the embarrassment of FRES UV behind it, the Army switches to FRES SV, a replacement for CVR(T)

Return to Contingency

2012 to 2014, as an end to the Afghanistan deployment drew near, Scout continued and attention turned to Warrior.

AJAX to MIV and the Emergence of Strike

2015 to 2017, a new medium weight capability vision emerges, and this requires a new vehicle, the Mechanised Infantry Vehicle (MIV), but before that, Multi Role Vehicle (MRV).


A few thoughts and opinions.

Appendix A – Ajax

Weights, measures, variants and roles

Appendix B – 40mm Cased Telescoped Weapon System

A revolution in medium calibre weapons, but can we afford it?

Appendix C – Generic Vehicle Architecture

The essential glue that binds the increasing quantity of vehicle electronics

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