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Intended to equip the Ajax reconnaissance and Warrior infantry fighting vehicles, the Cased Telescoped Armament System (CTAS) comprises the CT Cannon, Ammunition Handling System, Controller, Gun Control Equipment, Gun Mount and a range of ammunition natures.

It will also equip a number of French Army vehicles, the system as a whole being the result of a joint development programme and joint BAE/NEXTER venture called CTA International.


CTAS History

Cases telescoped ammunition was conceived by the USAF in the mid-fifties for use as an aircraft weapon;

Cased Telescoped Ammunition and Gun Technology. Air Force laboratory personnel conceived the cased telescoped ammunition concept in 1954. The cased telescoped concept places the ammunition projectile completely within the cartridge, instead of protruding from the top of the cartridge as in conventional ammunition. Further, the cased telescoped ammunition cartridge is formed into a right-circular cylinder, instead of a tapered cylinder as in conventional ammunition.

Despite US research activity, it would be the UK and France that would go on to bring into service a cased telescoped automatic cannon.

Years later the Combat Vehicle Armament Technology (COMVAT) programme was intended to produce an improved M2 Bradley with a 30mm-50mm version of the cased telescoped weapon developed by Armament Research and Development center (ARDEC) with Alliant Techsystems as prime contractor, building on an earlier programme called Combat Vehicle Armament System Technology (CVAST). ARES was also involved with the ARES 45mm XM295 cannon.

ARES would go on to develop the 45mm ammunition for their Rarefaction Wave Gun Programme project.

Recognising the approaching obsolescence of the 30mm RARDEN cannon, the MoD started a series of trade studies in order to develop the concept for a medium calibre weapon to replace it, one suitable to deal with the emerging Russian combat vehicles.

These trade studies prompted GIAT and Royal Ordnance to explore options for a collaborative development programme.

A Royal Ordnance and GIAT 45mm Cased Telescoped Weapon System (CTWS) demonstrator was completed in 1991 with the prototype the following year.

This demonstrator had some input from the ARES 45mm weapon that had been in development in the USA. Differences from the older US system included a change from metallic to plastic for the ammunition case and the use of electrical drive rather than being gas-operated.

Alliant Techsystems and Giat International signed a cooperation agreement in late 1992 to promote the 45mm weapon system but this did not progress and the Giat/RO relationship further developed.

The CTWS was intended for TRACER, a mid-life Warrior upgrade and the French VAD.

In 1992, Staff Target (Land) 4061, more commonly known as TRACER, Tactical Reconnaissance Armoured Combat Equipment Requirement was issued, to be the new CVR(T) replacement. TRACER was intended to utilise the 45mm CTWS.

In 1994, the joint development concept was formalised by the creation of a 50/50 Joint Venture between GIAT and Royal Ordnance called Cased Telescoped Ammunition International or CTAI for short. 30% of the funding for this joint venture was provided by the MoD and French Defence Ministry.

The US Department of Defense Inspector General released a technical evaluation in 1996 on cased telescoped ammunition.

In the same period, the US Army started looking at a replacement for its Bradley M3 in Cavalry squadrons, and the M1114 HMMWV ‘Humvee’ in scout platoons, in a programme called the Future Scout Cavalry System (FSCS). The TRACER and FSCS programmes were subsequently harmonised and a joint project was created. Both nation’s requirements would be met by a single vehicle, the Armoured Scout and Reconnaissance Vehicle (ASRV). The Armoured Scout and Reconnaissance Vehicle were specified in a Memorandum of Understanding signed by the US and the UK in July 1998, the original Operational Requirements Document having being agreed in December 1997. France and Germany both requested observer status on TRACER although neither had a comparable requirement.

Contracts for an initial study phase were signed with two consortia, each composed of a mix of UK and US companies, in January 1999. The mix of UK and US companies was intended to facilitate an equal work share between the native industries of the two nations.

In 1997 the decision was made to move the calibre to 40mm and rename it the CT2000 (rather optimistically, as it would turn out to be).

Two years later, in 1999, further interest from the USA resulted in a representative turret containing the 40mm CTAS integrated onto a US Army Bradley infantry fighting vehicle.

40mm CTA 40 Bradley 1

Firing trials were conducted soon after.

40mm CTA 40 Bradley 2

In April 2001, a statement to the House of Parliament revealed that the future of the US FSCS was in doubt, describing how the new Future Combat System (FCS) vision as envisioned by General Shinseki in 1999 would need funding and some programmes would be cut to make room for it, one of these was the follow-on engineering development phase of FSCS/TRACER.

In October 2001, a statement was made to Parliament that in a joint US/UK decision, TRACER would come to a close at the end of the assessment phase in July 2002. The information gained would be used to inform FCS and FRES respectively, both programmes were to effectively absorb TRACER and FSCS.

The CTWS 40 was still in development under separate contracts, so it was not impacted by the cancellation of TRACER and would likely form part of the FRES programme.

Various testing activities continued; icing, resistance to impact and fire, aircraft carriage and compound angle firing, for example.

CTA 40 Testing

Although not specifically aimed at any one vehicle the Manned Turret Integration Programme (MTIP) was a technology demonstrator working on the integration of the 40mm CTWS and a number of different sensors.

A demonstration contract was placed with Cased Telescoped Ammunition International (CTAI) to complete risk reduction demonstrations on a manned turret, feed systems and other sub-systems.

CTA was required to demonstrate the CTWS in a manned turret fitted to a Warrior by the end of 2006. The French Délégation Général pour l’Armement (DGA) also placed a contract with CTA for an unmanned turret called TOUTATIS, again, to be trialled on Warrior.

MTIP and TOUTATIS, shown below, left and right.


CTAI had been working on turret integration since 2003 and had demonstrated early models of both turrets on Warrior, the manned turret providing Level IV protection at a weight of 3.8 tonnes and the unmanned turret providing Level III protection but at the much lower weight of 1.5 tonnes.

The unmanned turret also had all the ammunition within the turret and a simpler feed mechanism, carrying capacity was 68 rounds, compared to 42 for the manned turret.

The Objective Future Cannon Programme (OFCP) was initiated in 2002, a joint programme between the UK MoD and French DGA. This defined the future programme activities and a number of key user requirements and specifications;

  • Rate of Fire 200 Shots per minute
  • Fire two ammunition types selectable <3s
  • Remote operation
  • Low integration volume <80 litres total swept volume
  • Dispersion > <0,35 mil APFSDS > <1 mil GPR
  • Minimum Fatigue Safety Life 10,000 rounds
  • Operates in safety –46°C to +63°C
  • Satisfies prevailing UK MoD and French DGA safety standards
  • STANAG 4439 insensitive
  • Reliability >98%
  • Supports ‘coincidence’ fire control solution

The first firing demonstration of the CTAS on a Warrior was in January 2002, in the ‘Xena’ turret, shown below.

CTA 40 Xena Turret

The original intent was that the 40mm CTAS would be central to the Warrior Fightability and Lethality Improvement Programme (WFLIP) but in 2005, the MoD announced a competition, despite the significant investment in the CTAS since the early nineties.

The competition originally specified a minimum calibre of 35mm but this was subsequently changed to 30mm to allow other guns to compete.

Competing bidders included General Dynamics with a version of their Mk46 turret, as fitted to the proposed USMC Expeditionary Fighting Vehicle and now used in naval applications, Selex offered a Mk 44 Bushmaster in the Oto Melara HITFIST turret, Lockheed Martin/Rheinmetall, a modification of the existing Warrior turret with Bushmaster 30mm, and CTAI/BAE, the 40mm CTAS in MTIP-2.

Lockheed Martin Warrior Turret Rebuild

Warrior LM



Additional firing trials were carried out in 2004 at Ridsdale Ranges.

40mm TA Firing Trials

France and the UK agreed on a common certification process for the 40mm CTWS in March 2006.

In April 2008, the MoD announced that the CTA International 40mm CTWS had been selected for both the Warrior and FRES Scout, although the MoD chose not to select a turret design.

In response to the MoD’s requirements, the industry had bid for both cannon and turret.

General Dynamics then withdrew from the competition, leaving Selex, BAE and Lockheed Martin, all but one now facing the prospect of redesigning their turrets to include the mandated 40mm CTAS.

Selex withdrew later in the year, leaving Lockheed Martin and BAE to compete for the requirement.

At the June Eurosatory show, BAE showed their largely self-funded MTIP-2 turret on a Warrior chassis. The MTIP-2 turret was a brand new design with a fully stabilised 40mm CTWS and applique armour package that provided the same protection level as the hull.


As can be seen from the above, the original MTIP and later BAE MTIP-2 turrets are clearly different.

By the end of 2009, after Lockheed Martin had been awarded a study contract to investigate a common Warrior/FRES turret, it became clear that there would need two turret variants, one for Warrior and the other optimised for the reconnaissance role.

BAE and General Dynamics promoted their respective entries for FRES SV at the beginning of 2010, BAE emphasised the benefits of a common turret, although with slight differences depending on the role. Outwardly there was little to distinguish the two, both used already in service infantry fighting vehicles of nineties origin as the base platform and both were equipped with the mandated 40mm CTA cannon, a range of C4ISTAR, protection and various automotive and protection upgrades.

FRES Scout Contenders

BAE announced their investment of £4.5 million in a Turret Test Rig for both Warrior and FRES programmes in February 2010.

The £4.5m Turret Test Rig (TTR) will mimic the field testing of turrets for Future Rapid Effect System (FRES) Scout and Warrior vehicles by subjecting them to tests under extremes of temperatures. The tests are expected to take a turret through a 20-year lifespan in 12-18 months.

Further development and qualification of the 40mm CTA weapon were agreed upon by France and the UK in February.

In March 2010, it was announced that General Dynamics had been selected for FRES SV Recce Block 1, or more specifically, selected as the preferred bidder.

It also emerged that General Dynamics would use a turret provided by Lockheed Martin, the actual design based on the Rheinmetall LANCE medium calibre turret. The selection of Lockheed Martin as the turret supplier was greeted with surprise by many in the industry as they had very little or no experience with the CTA system and the decision ignored both BAE and Nexter designs that were relatively mature.

With the General Election out of the way, the MoD and General Dynamics announced successful negotiations in June 2010 and the award of a £500 million contract for the Demonstration and Manufacture phase of FRES SV Recce Block 1.

In February/March 2010, alongside FRES, the MoD was also considering the future of the Warrior Capability Sustainment Project (WCSP), a competition between BAE and Lockheed Martin. Lockheed Martin proposed an upgrade of the existing Warrior turret and BAE, their MTIP 2 design,


In late March 2010, the MoD Investment Approvals Board recommended a year-long delay to WCSP. Lockheed Martin was awarded the Warrior Capability Sustainment Programme (WCSP) contract in October 2010.

The demonstration phase was expected to cost £200 million and manufacture £642 million. WCSP was designed to extend the service life of Warrior beyond 2040. At this point, Lockheed Martin was still insisting an upgraded Warrior turret would be used for the WCSP vehicles.

By the end of 2011, Lockheed Martin had been selected by General Dynamics to provide the Scout SV turret and by the MoD to provide the WCSP turret, as part of the wider programme.

Both, with different turrets, same main gun.

In summer 2013 a number of Warrior announcements were made;

Procurement of Cased Telescoped Cannons (CTC) Ammunition

The Specialist Vehicle Cannon Project Team, part of the UK Ministry of Defence, intends to place a further buy of ammunition, with CTA International through an Amendment to Contract No FRES/0075, to support the demonstration phases of the Cased Telescopic Cannon which will be provided to Prime Contractors for integration into the Scout Specialist Vehicle (SV) and the Warrior Capability Sustainment Programme (WCSP)

Total final value of contract(s)

Value: 25 629 034 EUR Including VAT. VAT rate (%) 20

A representative Scout prototype was shown soon after.


Towards the end of 2013, news emerged of problems with the Scout turret. Defense News reported that General Dynamics had agreed to pay Lockheed Martin several million pounds in compensation for failing to keep to a timetable on requirement delivery. It also reported problems with weight growth and a delayed ISD. Defense Industry Daily has a concise summary of the Warrior upgrade programmes, click here to read.

After a series of successful design reviews and 40mm CTA qualification in early 2014, the WCSP achieved Initial Design Approval in January 2014. Qualification firings included the APFSDS-T and practice rounds.

News emerged in 2014 that confirmed a decision by Lockheed Martin to abandon the Warrior turret conversion and proceed with a new turret design, this was no doubt cold comfort to BAE, who had insisted from the start that a new turret would be needed. The whole programme was ‘re-baselined’.

In 2015, the MoD finally placed a production order for the CTWS, although there was an announcement in 2015 for a £75m order

The deal with the joint BAE/NEXTER company CTA International was for £150m and will provide 515 weapons for the SV Scout and Warrior vehicles. The contract also included initial spares, test equipment, specialist tools and some training.

There were planned to be 245 for the Scout and 245 for Warrior, the balance being used for training, trials and ammunition qualification.

Defence Secretary Michael Fallon said;

Today I can announce we have signed a £150 million contract to fit the Scout with a new Cased Telescope cannon providing it with unrivalled firepower and a new ‘airburst ammunition’ capability.

France has also selected the CTAS 40 for use on their EBRC (Engin Blindé de Reconnaissance et de Combat) vehicles that will replace the AMX-10RC and Sagaie vehicles, using a common 2 man turret, the T40.

There was also some talk of a CT40 equipped Leclerc a few years ago, called the Leclerc T40, also proposed for the  Engin Blindé de Reconnaissance à Chenille (EBRC) programme. Nexter was in competition with Panhard with their Sphinx vehicle, fitted with yet another turret for the CT40 that has drawn on expertise from Lockheed Martin UK and Cockerill. Panhard no longer lists the Sphinx on their website. The Nexter Jaguar (VBMR) will join the Griffon (EBRC) in the 5 Billion Euro Scorpion programme, announced in December 2014.

Griffon and Jaguar (left and right)




The 24 tonnes Griffon will be obtained in a personnel carrier, ambulance, command and control and artillery observation, to a maximum of 1,722 vehicles, delivery starting in 2018. A lighter 4×4 VBMR variant is also planned for delivery after 2021, replacing the PVP and VBL vehicles. The 25-tonne Jaguar will be obtained in a quantity of 248. The Scorpion programme also includes the modernisation of the LeClerc Main Battle Tank that will extend its out of service date to 2040.

Nexter has also shown a VBCI-2 equipped with a T40 turret, the same turret that is used on their Engin Blindé de Reconnaissance et de Combat (EBRC) vehicles. If the UK does select the VBCI to satisfy the future Mechanised Infantry Vehicle (MIV) and chose the T40 equipped turret version, it will have three different turret designs, each equipped with the same weapon system.


Although the trials and tribulations of TRACER, FRES and Warrior have not significantly impacted the CTAS 40, there is no doubt that it has not been a smooth development, clearly, something that takes nearly 30 years to bring into service is not without problems, but by late 2015, qualification tests passed and a production contract awarded.

In early April 2016, AJAX completed its first instrumented static live firing at Radnor Ranges in Powys, Wales.

Ajax First Live Fire Image

AJAX First Live Fire 1

Ajax First Live Fire Video

Commenting on the test, the Senior Requirements manager for the AJAX Program, Lt. Col. David Cathro said;

This a great achievement for the program,the challenges in getting to this point should not be underestimated and today [Friday] is the result of a lot of hard work. Seeing the firings today gives us confidence that the Army will receive this battle-winning and transformational capability on time and to budget.

Testing and qualification continued and in June 2016, the MoD issued a £12.9 million contract extension to CTAI for additional qualification.

The DE&S Specialist Vehicles Cannon Delivery Team, part of the Ministry of Defence (MOD) intends to place an amendment to contract MATT/CCAP/003 (Common Cannon and Ammunition Project — 40mm Cased Telescoped Cannon and Ammunition Qualification Programme) with CTA International (CTAI), the designer and manufacturer of the Cased Telescoped Cannon and Ammunition (CTCA) to provide services required to conduct the qualification of a Target Practice Reduced Range (TPRR) type of ammunition on behalf of the United Kingdom and French Authorities. The qualification services will comprise an initial confirmatory phase of ammunition firing trials, plus options to undertake full ammunition firing trials, testing, evaluation activities and commissioning of a production facility thereafter

In July 2016, Nexter announced the private development of a new turret family built around the CT40.

The MoD issued a contract amendment to CTAI for further qualification of the Target Practice Reduced Range round

Amendment to contract MATT/CCAP/003 with CTA International (CTAI) to provide services required to conduct the qualification of a Target Practice Reduced Range (TPRR) type of ammunition on behalf of the United Kingdom and French Authorities

The cost of this was 16.5 million Euros.

In March 2016, the first production systems were handed over:

The first production standard Cased Telescoped Cannon System has been handed over to the UK Ministry of Defence (MOD) in Bourges, France by CTA International (CTAI) – a 50/50 joint venture company between BAE Systems and Nexter Systems

Ajax manned live firing trials commenced in September 2017, a spokesperson from General Dynamics said:

The start of the CT40 cannon manned industry firing phase is a significant milestone in the AJAX programme. This cutting-edge capability that enables AJAX to pack a significant punch, alongside its wide-range of best-in-class sensors that makes it an Information Age platform, ensures that the British Army has everything they need to do their job effectively

Production and qualification continued on both Ajax and Warrior and the Lockheed Martin Modular Turret was been tested on both Boxer and AMV vehicles.

In March 2018, CTA International demonstrated the 40mm CTWS to US Army personnel at Fort Benning, Georgia. 80 rounds were fired, including a number of the A3B air bursting nature. One of the scenarios demonstrated a typical wall breaching operation, two rounds of point detonating to create a hole that was followed by an air bursting type fire through the hole.

In evidence sessions to the House of Commons Parliamentary Select Committee on Defence, both Lockheed Martin and General Dynamics laid the blame for delays with Ajax and Warrior CSP on the 40mm CTAS, however, this was countered by the MoD.

Warrior CSP was cancelled in 2021

After the cancellation of Warrior CSP, it was reported that surplus weapons might be disposed of and an investigation into improving the lethality of Boxer was carried out.

The Army is conducting an analysis on potential lethality enhancements of Boxer vehicles. As outlined in the recent Integrated Review, modernizing our armoured capabilities is not replacing ‘like for like’ but integrating our new technologies and ways of operating

Capabilities and System Description

The CTAS is described by several components; 40mm CT Cannon (CTC), Ammunition Handling System (AHS), CTAS Controller (CTAS-C), Gun Control Equipment (GCE), Gun Mount and a range of ammunition.

40mm CTAS

The gun is designed to be compact.

40mm CTAS Gun

As can be seen from the images below, the payload is fully contained within the case, this is what is meant by ‘case telescoped’, the main reason to do this is space efficiency.

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CTAI is marketing seven ammunition natures, six shown in the image below.

CTA 40mm Natures

The first of these is the 1.9kg Armour Piercing Fin Stabilised Discarding Sabot – Tracer (APFSDS-T) that is designed to defeat armoured vehicles such as infantry fighting vehicles and legacy tanks (although thinking that it can defeat modern tanks would be incorrect, and possibly dangerous). Able to penetrate 140 mm of RHA (Rolled Homogeneous Armour) at 1500m, it has a muzzle velocity in excess of 1,450m/s and the projectile itself, weighs just over 500g, and has an effective range of greater than 2,500m.

40mm CTAS Armour Piercing Fin Stabilised Discarding Sabot - Tracer (APFSDS-T)

A more conventional 2.4kg KE round (GPR-KE-T) provides a lower cost option for light armoured vehicles, fixed defences and similar targets. The maximum range is 8,500m and the projectile mass is 980g.

The Target Practice Reduced Round-Tracer (TPRR-T), is used for training, is cheaper, and results in much less barrel wear. A normal range Target Practice – Tracer (TP-T) is also available.

There are two general-purpose rounds, one point detonating (General Purpose Round – Point Detonating – Tracer (GPR-PD-T)) and the other providing an airburst capability (General Purpose Round – Point Detonating – Tracer (GPR-ab-T)) which can be used against troops on a reverse slope or behind light cover, for example, it can also be used in point detonating mode. Both use IM compliant HE, 115g per round.

The image below shows a fragmentation comparison between a 30mm airburst round (left) and the 40mm GPR-AB


The lethal area for the airburst nature at 1,500m is 125m2.

The 2.4kg point detonating nature can penetrate 210mm of reinforced concrete at 1,500m.

The 1.4kg Anti-Aerial Air Burst (A3B) has a longer range and a payload of tungsten pellets designed to defeat airborne targets to a maximum effective range of 4,000m.

The round is inserted into the breech block through the trunion and the rotating breech block then aligns it with the barrel, thus eliminating the need for flexible feed guides. There are a couple of variations but the UK version will have a dual-feed system, most likely loaded with the APFDS and GPR, although other mixes may be used depending upon requirements. The system can swap from one to the other in less than 3 seconds.

A fire control system designed and manufactured by Ultra is the final component of the system,

40mm CTA Fire Control System

Anecdotally, the cost of the new ammunition is said to be ‘eye watering’, reliability and supportability have also yet to be determined in service.


Although work has recently concentrated on bringing the system into service CTAI has also carried out a number of studies on larger calibre (105mm), guided submunitions and a 12.7mm version.

CTA Developments

Testing has also confirmed the suitability of the 40mm CTAS for use in remote and unmanned mounts, including dual/triple feed and non-penetrating options.

40mm CTA Remote Mounts

The image below shows a non-penetrating remote mount fitted to a French VAB combat vehicle.

40mm CTA Remote Mount VAB

CTAI has also proposed a number of naval applications for the CTAS but the most recent development is the Thales RAPIDFire system, designed to destroy helicopters, unmanned vehicles and combat aircraft.

Thales RAPIDFire

RAPIDFire Video

The RAPIDFire vehicle can be integrated with a number of air defence systems and uses the specialised air defence ammunition that contained 200 tungsten pellets. Rather than using a very high rate of fire, RAPIDFire is designed to fire fewer but more effective air bursting rounds at the target. It can carry 140 rounds in the turret, ready to fire. Effective range is claimed to be 4,000m and up to 6 vehicles can be integrated with a single control module for wide-area coverage, including fire control for Starstreak/HVM missiles. An independent EO/IR sensor can also be used with detection ranges in excess of 18km.

In 2013, Aviation Week reported interest in an aircraft version;

Someone was looking at putting the gun on a C-130 gunship,” he says, declining to identify the individual. “It was a U.S. company that got our data somewhere, and maybe it will give them an advantage over other bids. I was surprised when I got it. But the cannon is 300 kg (660 lb.) and has very short recoil. Of course, you have to control the pulse, but why not [put it on an aircraft]? We’ll see what happens next.”

With Airbus recently reported to be interested in developing ISTAR/combat payload enhancements for the A400M and the recent success of the C-295 Gunship conversions for Jordan, this may be one to watch.

Nexter market an advanced 2 person turret with the 40mm CTAS

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Thales has also started to market the naval 40mm CTAS weapon in the RAPIFire system.

A Few Closing Thoughts

Why has the UK and France persisted with this approach when there are many more conventional options like Super 40, for example?

Quite simply, it is one of space, although additional armour piercing performance is always a good thing.

Modern vehicles need modern electronics, and contrary to popular belief, modern electronics, at least in combat vehicles, are not getting any smaller. Modern vehicles also need modern people, and modern people are larger and wear combat body armour, we also can no longer insist armoured vehicle crew are small in stature. All this places a premium on internal turret volume, so anything that reduces the volume of one of the main turret components simply means more room for ammunition, electronics and ergonomics i.e., a good thing.

This comes at a cost however, the CTAS is expensive (regardless of arguments about the cost per stored kill) and unless others purchase it, only in service in relatively small numbers. The burden of ongoing qualification and development will fall disproportionately on France and the UK. There are wider arguments about the concept of operation for armoured infantry and reconnaissance forces and their need for such a high performance, and expensive, weapon, but they are outside the scope of this document.

Regardless of whether anyone thinks the CTAS is a good idea or not is irrelevant, to coin a phrase, we are where we are.

The question the UK faces is whether to double down or carry on with the CTAS in service on just one vehicle type. In order to maximise commonality, realise economies of scale and provide confidence and impetus to an export campaign.

Export customers mean shared development costs and lower ammunition costs.

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Change Status

Change Date Change Record
 06/02/2017 Initial issue
 18/09/2017 Additional imagery of 45mm CTA
 04/03/2018 LM modular turret information
 08/04/2018 Additional information on US interest
 22/07/2021 Update with Warrior CSP Cancellation
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