Built on proven artillery systems such as the AMF3 gun, the 155 GCT AUF1 self-propelled gun and the 155 TRF1 towed gun, CAESAR is the optimum combination of their features.

Versatility, mobility, easy to operate, combat readiness and survivability are the key features of this new 155 mm/52-caliber weapon system which is fully interoperable with the NATO 39 cal. equipment and 52 cal. JB MoU.

From a mobility and maintenance viewpoint, the self-propelled artillery systems are penalized both by their weight and their tracked chassis.

Towed guns are disadvantaged in terms of manoeuvrability and survivability by their size and their design. The genuinely versatile CAESAR® as to it, fills the gap with the innovative solutions it offers and meets the operational requirements, whatever the conflict level, the theatre of operations and the nature of forces involved.

CAESAR can support all types of motorised, mechanised and armoured units, including rapid deployment forces.

CAESAR offers enhanced fire power through quicker response, longer range and improved accuracy. It covers larger areas with fewer guns and favours initiative, manoeuvring and quick reaction time while minimizing risks.

CAESAR is effective in each fire mission such as: direct support fire, in-depth action fire, counterbattery fire and even in coastal defence missions.

Giat Industries (which in late 2006 became Nexter) developed a 155 mm self-propelled technology demonstrator called CAESAR (CAmion Equipé d'un Système d'ARtillerie, or truck-mounted artillery system) and this was shown in public for the first time in June 1994.

Following trials with this system, a decision was taken by the company to build a pre-production CAESAR and following company trials, this was evaluated by the French Army late in 1998.

In September 2000, the French Délégation Générale pour l'Armement (DGA) awarded the company a contract for the supply of a batch of five 155 mm/52 calibre CAESAR (6 × 6) self-propelled artillery systems.

This contract included the following key aspects:

• Complementary developments featuring the additional French Army requirements

• Type qualification totally relying on the contractor

• Delivery of five CAESAR systems

• Maintenance and support over a period of three years.

These were integrated at the now Nexter Systems facility at Bourges with the cab being supplied by SOFRAME (previously LOHR) which has been installed on the modified Mercedes-Benz (6 × 6) truck chassis.

By this time the company had built two CAESAR systems. The first CAESAR was essentially a technology demonstrator to prove that it was possible to mount a 155 mm/52 calibre artillery system on a modified Mercedes-Benz UNIMOG U 2450 (6 × 6) truck chassis.

This was followed by a second model which has been evaluated by the French Army and late in 1999 went to Asia.

The third CAESAR incorporated all of the lessons learned with the French and Malaysian trials and is essentially a preproduction vehicle.

This is fitted with a revised fully enclosed crew cab with improved air conditioning and upgraded computer software. This CAESAR was the baseline for the French Army version, which has the ATLAS computerised fire-control system and a land navigation system which is now fitted to the French Army AUF1 upgraded self-propelled artillery system.

The first CAESAR systems were delivered to the French Army late in 2002 with final deliveries taking place in early 2003. These have been used by the French Army to form one complete artillery troop of four CAESARs with the 5th being used for training and reserve.

This CAESAR troop is being used to evaluate operational procedures for the deployment of the system by the French Army.

Late in 2002, the US Army Field Artillery School and Center hosted approximately 200 people to observe the CAESAR firepower demonstration at Fort Sill, Oklahoma.

In all, 100 per cent of the projectiles fired at Fort Sill were less than 50 m from the target and 20 per cent of them hit the target. At the firing position, the French crew fired six M107 projectiles in 57 seconds.

Late in 2003, following a detailed analysis, the French Army decided to purchase additional CAESAR SPGs rather that continue with the major upgrade of the AUF1 SP to the enhanced AUF2 standard.

In December 2004, the French DGA awarded the company a contract covering the supply of 72 CAESAR 155 mm/52 calibre self-propelled artillery systems for the French Army. It is expected that deliveries will run from 2007 through to 2011. Total value of this contract is EUR300 million, which includes ammunition, a five-year logistic support package and the upgrade of some CAESAR systems already delivered to the French Army.

Under the terms of this contract, the company is committed to ensure an 80 per cent rate of operational availability of the system with full responsibility for the spares and repair management.

The French Army will continue with the AUF1 upgrade for the 70 systems but will not at present move to the 155 mm/52 calibre unless funding becomes available in the future.

While the weapon system will be manufactured at the Bourges facility, integration of the complete weapon with the chassis will take place at Roanne.

Production CAESAR systems will be based on the new Renault Trucks Defense Sherpa chassis (6 × 6) which will be fitted with a fully armour protected cab also supplied by Renault Trucks Defense. The first production verification CAESAR system on the Sherpa chassis (6 × 6) was completed in mid-2006.

Apart from the new chassis and cab this will have only minor differences when compared to the first CAESAR systems. The muzzle velocity radar, for example, is now on the right side of the ordnance rather than above the ordnance.

In the future it is expected that the French Army will have a total of eight field artillery regiments with each of these having three batteries each with eight weapons with two troops of four guns.

Four regiments will have two batteries with a total of 16 upgraded tracked SP AUF1 TA weapons and one battery of eight CAESAR with the remaining four regiments having two batteries with a total of 16 TR F1 towed guns and one battery of eight CAESAR. In the longer term additional CAESAR are expected to be procured.

In April 2006 the company announced that Thailand had placed a contract with the company for an initial six systems with the total requirement understood to be for at least 18 units to enable a complete CAESAR regiment to be formed.

In July 2006 the company announced that an undisclosed export customer had placed a contract with the company for 72 CAESAR systems.

These systems are for the Saudi Arabian National Guard and will be integrated onto a SOFRAME-UNIMOG (6 × 6) chassis and fitted with a Thales ATLAS computerised fire-control system.

It should be noted that while all examples of the CAESAR built to date have been based on a Mercedes-Benz (6 × 6) truck chassis, all production CAESAR systems for France and Thailand are built on a new Renault Trucks Defense Sherpa (6 × 6) truck chassis. CAESAR is based on a 6 × 6 truck chassis which, as well as providing good cross-country mobility, provides good strategic mobility as it can be rapidly be moved around without having to rely on tank transporters and semi-trailers. Additional details of the Renault Trucks Defense Sherpa 6×6 chassis are provided later in this entry.

For use in high ambient temperatures the cab is fitted with an air-conditioning system. The fully enclosed crew compartment is at the front with the 155 mm/52 calibre ordnance mounted at the rear. A central tyre pressure regulation system is fitted as standard that allows the driver to adjust the tyre pressure to suit the terrain being crossed. Power steering is also provided.

As CAESAR is mounted on a wheeled chassis its overall life cycle costs are much lower than a comparable tracked vehicle. This is of increasing importance as many users are now looking at the total life cycle costs of weapon systems rather than only the initial procurement cost.

A new fully enclosed cab has been mounted at the front of the vehicle and has individual seats for the crew of five. The cab is of welded steel armour and provides protection from small arms fire up to 7.62 mm in calibre and shell splinters. The cab windows are 26 mm thick and the cab is fitted with an air conditioning system.

Mounted at the rear of the CAESAR is the complete upper part of the 155 mm 52 calibre upgraded version of the TRF1 towed artillery system. The 155 mm 52 calibre ordnance is fitted with a double baffle muzzle brake and when travelling the ordnance is held in position by a clamp, located to the immediate rear of the cab, which is operated by remote control.

When the system is deployed in the firing position a large spade is hydraulically lowered at the rear to provide a more stable firing platform. The rear four wheels are raised clear of the ground so that the large spade absorbs all the firing stresses. CAESAR can come into action in less than 1 minute and come out of action in a similar period. According to the company, in less than two minutes this system can fire six projectiles, come out of battery and start to move to another position. This means that it would be difficult to engage CAESAR with counterbattery fire.

The 155 mm 52 calibre ordnance, which was developed some years ago for the 155 mm 52 calibre upgraded version of the TRF1, is fitted with a screw breech mechanism that opens upwards automatically with a revolving automatic primer feed mechanism holding 14 primers. It conforms to the latest NATO Joint Ballistic Memorandum of Understanding (JBMoU). An electrical firing device is fitted as standard.

CAESAR is a self-sufficient self-propelled artillery system as no survey team is required due to the installation of a SAGEM SIGMA 30 onboard reference package/position data system (RP/PDS) which includes a Global Positioning System and which is mounted on the actual gun.

An Intertechnique RDB4 muzzle velocity radar is mounted over the ordnance and this feeds information to the Matra Défense Equipements & Systèmes CS 2002-G onboard fire-control computer which is located in the cab together with its printer.

This receives target information from the battery command post with ballistic computation taking place on the system. French Army systems are fitted with the Thales PR4G radios.

The CS 2002-G computer also carries out a number of other functions including 3-D display of friend or foe local situation. With the aid of integral sensors it can also carry out ammunition status management, gun status management and ammunition resupply management.

There is also a temperature control device that advises the crew if the ordnance is becoming too hot and there is a danger of a cook off.

To reduce crew fatigue and increase the rate of fire an automatic projectile loader is mounted to the right side of the breech. The propelling charges, which can be of the conventional type or the more recent modular charge type, are loaded manually.

Maximum rate of fire is 6 rds/min and according to Nexter a burst rate of fire of three rounds in 18 seconds is normally attained.

Elevation and traverse is hydraulic with manual controls being provided as a back-up. For indirect usual firing elevation ranges from +17 to +66° with traverse being 17° left and right. For direct firing elevation ranges from -3 to +10° right, with traverse between 21° left and 27° right. Aiming is carried out automatically via the onboard computer but optical sights are provided as a back-up.

Maximum range depends of the nature of ammunition and charge system but firing a 155 mm ERFB-BB (Extended Range Full Bore-Base Bleed) a maximum range of 42 km can be achieved.

The main fire-control computer is located in the cab of the CAESAR but at the rear on the left is the gun display unit for the crew when the system is deployed in the firing position. This provides such information as elevation, traverse, projectile, charge and fuze type.

The main advantages of the CAESAR are that it has similar firepower to existing towed and self-propelled artillery systems with greater strategic mobility and quicker in/out of action times. The last feature also enhances the combat survivability of the system to counter battery fire. The standard 155 mm TRF1 has a crew of eight while CAESAR has a crew of only five including the commander and driver.

The design of CAESAR is modular so that the customer can select which radio, fire-control system or muzzle velocity measuring system and type of cab required.

As well as being transported by air, for example Lockheed Martin Hercules C-130 and Transall C160, CAESAR can also be carried by landing craft, surface ships and railway flatcars.

Nexter Systems have also developed an ammunition resupply vehicle which carries containers of ammunition (projectiles and charges) which can be rapidly unloaded using an onboard hydraulic crane. A total of six containers are carried which hold a total of 72 rounds (projectiles and charges) of 155 mm ammunition. Conventional bagged charges can be used as well as the more recent modular charge type.