United Kingdom (1963)

Armoured Vehicle Royal Engineers

While it was still under development in 1960, the Royal Engineers (RE) requested specialist conversions of the UK’s new Main Battle Tank (MBT), the FV4201 Chieftain to replace the Centurion models then in service. One of the requested specialist vehicles was a new AVRE (Armoured Vehicle Royal Engineers) to replace the FV4003 Centurion AVRE. At this time, these specialist vehicles were still called ‘Funnies’, after their famous ancestors in the 79th Armoured Division, ‘Hobart’s Funnies’. It made sense to design these specialist vehicles based on the MBT of the time to ease production, training, and have a plentiful supply of spare parts.

Following feasibility studies in 1963, designs were put forward in May 1965, and September 1966. These designs were designated Armoured Engineer Vehicles (AEV)s. There were two versions. These were the ‘W’ and ‘G’. The AEV (W) would be an unarmed variant with no turret or large caliber armament. It would be equipped with a 30-ton capacity winch, hence the identifier ‘W’. It would also carry the No. 7 twin-track bridge, a short bridge able to be placed across ditches or trenches. It was intended to replace fascines. The AEV (G) retained its turret and carried the same 165mm Demolition Gun (hence the identifier ‘G’) as the Centurion AVRE. It would also carry an ‘A-frame’ crane on the turret in a configuration similar to the American M728 CEV (Combat Engineer Vehicle). An Armoured Vehicle Launched Bridge (AVLB) variant was also designed.

All of these were intended to replace the Centurion-based models then in service. Fifteen AEV (G)s, which had acquired the designation FV4207, were requested as well as 53 AEV (W)s. However, come 1967, the AEV (G) was canceled in favor of the (W). The cancellation of the (G) variant meant that the Centurion AVRE would have to remain in service for another 20 years. With development focussed on the AEV (W), it received the designation of Chieftain AVRE.



Design drawings for the Chieftain AEV (w) above, and the AEV (G) below. Photo: Haynes Publishing

The Chieftain

The FV4201 Chieftain, entering service in 1966, was designed as a replacement for both the Centurion and FV214 Conqueror. It boasted a powerful 120mm gun and tough armor that was up to 230 mm (9 in) thick. It was armed with the L11A5 120mm rifled gun. The tank was manned by a crew of 4, consisting of a commander, gunner, loader, and driver. The Chieftain was one of the first tanks in which the driver sat in a reclining, or supine, position, meaning the tank had a much lower silhouette than previous vehicles.

The tank weighed 55 tons. This weight was supported on a Horstmann suspension inherited from the Centurion. There were six road-wheels per side, attached to three, two-wheel bogies. The idler was at the front while the drive sprocket was at the rear. The tank was powered by the notorious 750hp Leyland L60 multi-fuel engine. The engine was designed to run on different fuels (Petrol, Diesel, even cooking oil) but it was extremely unreliable causing a lot of breakdowns.

After a number of upgrade programs resulting in 12 separate marks of the vehicle, the Chieftain was eventually removed from service with the British Army in the early 1990s. It was replaced by the Challenger I.

Non-Starter

Come 1969, the design of the Chieftain AVRE had been completed and two prototypes with No. 7 bridges were ordered. The basic configuration of the AVRE was similar to that of the Chieftain ARV (Armoured Recovery Vehicle) which was under simultaneous development and was equipped with the 3-ton winch and a dozer blade/earth bucket. The No. 7 Bridge was carried driving surface-down on top of the hull.

Development on the AVRE ceased in April 1969. This was due to the development of the Combat Engineer Tractor (CET) by the Royal Ordnance Factory (ROF) in Leeds, which was a fraction of the cost of the Chieftain variant. It soon became clear that funds would not be available for both vehicles. By the end of the 1960s, the development of both the AVRE prototypes was canceled, leaving the Chieftain AVLB (Armoured Vehicle-Launched Bridge) to be the only variant of the MBT under development for the Royal Engineers. The small CET, which became the FV180, would enter service in 1976.

Resurrected

By the mid-1980s, the Royal Engineers were even more eager to replace their now almost 40-year old Centurion AVREs. Also at this time, the Chieftain’s replacement, the Challenger I had started to be put into service. Realizing that a number of surplus Chieftain tanks would become available, the Chieftain AVRE program was resurrected.

A design not too dissimilar from the old AEV (W) concept, almost a simplified version, was drawn up and 13, later 17, surplus Chieftains were made available for the conversion program. Following the acceptance of the design, a wooden mockup was constructed. This was followed by the construction of two prototypes built on Chieftain AVLB Mk. 2 hulls. The conversions were done at Bovington Camp in 1984.

Design

This new AVRE would be operating alongside Challenger I. It was required that the vehicle maintain a high level of maneuverability and the best power-to-weight ratio possible. To achieve this, the turret was removed saving 12-tons. This, however, meant that the 165mm Demolition Gun was not added to the vehicle, making the Centurion the last armed AVRE used by the Royal Engineers.

It would have the ability to mount the standard-issue dozer blade or a modified version of the Centurion 105 AVRE’s mine plow. It could tow two four-wheel ‘AVRE Trailers’ or two Giant Viper (GV) mine clearing devices, doubling the capacity compared to the Centurion. On a UK road it was limited to 1 trailer however.

Atop the turretless hull, a three-piece superstructure was added. Known as the ‘roof-rack’ or ‘hamper’, it could carry three PVC ‘maxi’ pipe fascine rolls or six roles of Class 60 Trackway. Six welded legs secured the rack to the hull, the rearmost rack was fixed in place, but the back section of the middle and the front section of the forward rack could be raised or lowered hydraulically to drop fascines or Class 60 rolls off the front of the vehicle. It was also decided that the rack be capable of carrying a No. 9 Tank Bridge and other stores. Rollers were attached to the rack to facilitate the loading and unloading of the bridge. It must be stressed that the AVRE could not launch the bridge. It would only carry the No. 9 if it was operating in support of the Chieftain AVLB. A seventh roll of Class 60 could be carried on the rear of the hull. The vehicle could also stow its own dozer blade or mine plow in this location. A Rotzler hydraulic winch was also introduced. For close protection, a GPMG (General Purpose Machine Gun) light-machine gun was carried.

The vehicle had a crew of four. This consisted of the commander, driver and two engineers. The driver sat in the standard position at the front of the vehicle. The commander sat in the hull with the two engineers either side of him in very uncomfortable positions due to the low roof.

Production

To speed up the production of the vehicle and get it into service as quickly as possible, it was decided that all conversion work would be handled by the Army. Work started in February 1986 at the 21st Engineer base workshops in Willich, Germany. A total of 17 Chieftains were converted here. AVRE No. 1 was completed in August 1986, and was sent immediately for trials with the 32nd Armoured Engineer Regiment of the BAOR (British Army of the Rhine). This was to assess the design before full production started. This proved to be a wise endeavor, as a total of 40 modifications and additions were made to and for AVRE No. 2 & 3. The 4th converted vehicle became the finalized design. This was to avoid all 17 of the vehicles having different features and components. After No. 4, all of the AVREs were identical. The last Chieftain AVRE was completed by late 1987.

The completed AVREs were given the designations ‘AVRE Mk. 6/2C’. They were also sometimes known as the ‘Willich AVREs’. Sixteen of the AVREs were based on Mk. 2 Chieftains, with one solitary Mk. 1. The conversions were completed at the relatively cheap price of GB£80,000 each. Two further AVREs were completed at the base workshops of the 23rd Engineer Regiment in Wetter to fulfill the requirement of AVREs in BATUS (British Army Training Unit Suffield), Canada. This brought the total to 19 Chieftain AVRE produced and in service from the mid-1980s to the early 1990s.

Equipment

The role of the ‘CHAVRE’ was much the same as its Centurion and Churchill predecessors, carrying a vast array of battlefield engineering equipment, but specifically not combat as it did not carry an obstacle destruction gun.

Fascines

Just like the AVREs before it, the Chieftain could carry a large fascine over its front end in a cradle mounted on the upper glacis. Fascines had been carried by tanks since their earliest days on the devastated battlefields of the First World War, most notably at the Battle of Cambrai in 1917. Fascines are used to fill wide trenches or ditches to allow tanks to cross. The original fascines were fabricated from brushwood, bound tightly together into a cylinder. In the late 1950s, the Royal Engineers developed a new type, fabricated from large sections of PVC or ‘maxi’ pipe. This was lighter than the original wooden ones, but also allowed water to flow through stopping it from shifting or floating away when dropped in a ditch.



‘CHAVRE’ at Salisbury Plain in 2000. The vehicle is carrying two rolls of ‘maxi’ pipe fascine. It is also equipped with a mine plow, and is towing a 7½-ton trailer. Photo: T.J. Neate

Class 60 Trackway

An extremely versatile piece of kit, this portable metal matting could be used for a number of roles. These included forming a safe bridge approach, helicopter landing pad, stable road over boggy or soft ground, and a safe riverbank exit. The trackway was carried in the same cradle used by the fascine and was deployed in the same manner.

Dozer Blade

This hydraulically operated blade was fitted directly to the front of the Chieftain. The blade could be used for a number of tasks. These included carving out hull-down positions for gun tanks (this could be achieved within 7 minutes), digging gun emplacements, route denial (creating and filling anti-tank ditches), and improving bridge approaches. It could also be used aggressively to push barricades or debris from the path of attacking allies, and even clear inert unexploded mines. The blade was also used to flatten ground for the application of Class 60 Trackway by ‘back-blading’, dragging the blade backward over the ground to grade a uniform surface for the roadway to lie on.



A ‘CHAVRE’ of the 22nd Engineer Regiment, equipped with dozer, blade ploughs through a dirt pile. Perham Down, 1995. Photo: T.J. Neate

Towed Equipment

Trailer

The AVRE could haul one or two 7½-ton four wheel trailers that were designed to carry a fascine roll, two rolls of Class 60 Trackway, demolition charges, No. 7 Anti-Tank mines, RDD (Radiological Dispersal Device) explosives, and other engineering equipment. The trailer could traverse any terrain the tank could, without hindering it. It could be jettisoned when required via an exploding pin in the jointed towing hook.



An AVRE towing the 7½-ton trailer loaded with two trackway rolls. Photo: Haynes Publishing

Giant Viper

Another trailer borne-device which was towed by the AVRE. A further development of the World War Two ‘Conger’, the ‘Giant Viper’ was a mine clearing device use to clear large areas of explosive devices such as IED’s or landmines, or clear a path through barbed wire. The Viper was mounted on a trailer that was towed by the tank. It consisted of a 750ft (229 m) long, 2 ⅝ inch (6.6 cm) diameter hose filled with plastic explosives. The Viper would be launched over the tank via a cluster of eight rocket motors, then landing in the area that had to be cleared and exploding. The blast would clear a pathway 24 feet (7.3m) wide and 600 feet (183 m) long. The device was carried on the back of a unique two-wheel trailer.



Chieftain AVRE towing two ‘Giant Viper’ trailers, the rear of which is launching the Viper rocket. IT is also carrying 3 ‘maxi’ pipe fascines. Photo: Haynes Publishing

Service

Initially, nine of the AVREs went to the 23rd Engineer Regiment, five went to the 32nd Armoured Engineer Regiment, two went to BATUS (followed later by the two more built in Wetter) and a solitary AVRE went to Bovington Camp. Despite some initial teething problems with the general reliability of the Chieftain (the hulls converted were now around 30 years old), this new vehicle provided the Royal Engineers a flexible, hardworking vehicle able to support battle groups, armored divisions and even infantry with a range of engineering tools.

Gulf War

Fourteen Chieftain AVREs, accompanied by their older Centurion brothers, were part of the British contingent sent on Operation Granby, the codename given to British Operations in the 1990-1991 Gulf War. Here they received extra armor protection in the form of Explosive Reactive Armor or ‘ERA’, taken from Warrior MICVs. These were added to both sides of the crew compartment, adding a total of 1.2 tons to the vehicle. ‘Chain mail’ was added in the form of a net which was hung from the roof rack or ‘hamper’ as a defense against shaped-charge ammunition. This was not popular with the drivers as the chains reduced vision.



Sapper Matthew Newell, 39 Field Squadron, 23 Engineer Regiment, stands with a captured AK-47 assault rifle in front of his AVRE “Whoosh, Bang, Gone!”. Newell was the driver of this vehicle, its name came from the sound made when the Giant Viper mine clearing device was operated. Note the added chain net at the front of the vehicle, and stuffed toy decoration on the left. Photo: Matthew Newell Personal Collection

The AVREs proved very useful in operations in this theatre, serving admirably alongside the Centurion AVREs. Their only real mission, though, was clearing the Milta Pass, North of Kuwait. This was the Main Supply Route (MSR) to the Northern Border with Iraq and it was heavily blocked with wrecks of tanks, trucks, artillery pieces, civilian vehicles, rubble, and all kinds of unexploded ordnance thanks to numerous attacks by marauding US A-10 Warthog ground attack aircraft. All other routes were compromised as there were minefields everywhere on the side of the Basra Road connecting Kuwait City to Iraq. The Chieftains were used to tow and drag destroyed vehicles, while the Centurions shunted wrecked tanks off the road with their dozer blades in case any remaining ammunition cooked off (exploded).



Chieftain AVRE ‘Nice and Sleazy’, driven by Sapper Graham Aylward, 39th Field Sqn, 23rd Engr Rgt, in the Gulf. Photographed by Captain Neil Palmer RTR, Command Troop, 14/20th. Hussars, 4 Bde, RSO. Photo: Neil Palmer Personal Collection.

New Model

The AVRE’s success in the Gulf reinforced an idea from 1989, which called for the conversion of more surplus Chieftain hulls. These new AVRE would have a few improvements to the design. The rearmost hamper was fitted with hydraulics to allow the whole thing to tip backwards, allowing fascines or trackway rolls to simply roll off. A small, onboard hydraulic crane was also added. This would lift equipment onto the hull rear and was also used to load fascines and trackway rolls.



‘CHAVRE’ using the on-board hydraulic crane to steady roles of ‘maxi’ pipe fascines. The rear deck, carrying a roll of trackway, shows its abiliity to be tipped backwards. Photo: T.J. Neate

A total of 46 of these newer AVREs were constructed in two batches at ROF Leads, consisting of one batch of 30 and another of 16 constructed between 1991 and 1994. The vehicle received the official designation of ‘Chieftain Armoured Vehicle Royal Engineers’, but this was often shortened to ‘CHAVRE’. Once these newer model AVREs entered service, most of the older ‘Willich AVREs’ were retired, though a few remained in service as training vehicles at various camps and bases.

The CHAVRE saw active service in the Kosovo War of 1998-1999. Here they served with the British Contingent of the NATO force dispatched. The ERA configuration used in the Gulf was also used on the vehicles in this theatre. They were mostly used for route clearance and were predominantly used to clear the way for Podujevo camp in the north of the country.



Chieftain AVRE ‘CHAVRE’ in Kosovo, 2000. Photo: Chieftain Tank Apreciation Society group on Facebook

Fate

The ‘CHAVREs’ were finally removed from service in the early 2000s. They were replaced by the British Army’s currently serving Armoured Engineer vehicle, the Trojan.

A few Chieftain AVREs do survive today. One of the earlier ‘Willich AVREs’ can be found outside the Tank Museum, Bovington. For a time, a later ‘CHAVRE’ was also kept here in a running condition. It was displayed in a few of the Tank Museum’s events. It is believed that it has now been moved to the Royal Engineers Museum, Kent. Another can be found on display at the Chatham Dockyards near London.

Total productionAprx. 70

Specifications Dimensions (L-W-H) 25′ (Parx.) x 11’5″ x 9’5″

(7.5m x 3.5m x 2.89m) Total weight, battle ready Aprx. 43 tons (39 tonnes) Crew 4 (commander, driver, two engineers). Propulsion British Leyland diesel BL 40, 450-650 bhp, later BL 60, 695 bhp Speed 48/30 km/h road/cross-country (29.82/18.64 mph) Range/consumption 500 km (310.68 mi) Equipment PVC Pipe Fascine

Class 60 Trackway

Dozer Blade

Giant Viper Armour Glacis 4.72in, sides 1.37in (120/35 mm)

Links & Resources

Haynes Owners Workshop Manual, Chieftain Main Battle Tank, 1966 to Present.

Osprey Publishing, New Vanguard #80: Chieftain Main Battle Tank 1965–2003

www.armedforces.co.uk

www.army-guide.com

The Tank Museum, Bovington

Esteemed members of the the Chieftain Tank Apreciation Society Facebook Group

Photo walk-around: www.net-maquettes.com



FV4203 Chieftain Armoured Vehicle Royal Engineers (AVRE) in a two-tone camouflage pattern. The AVRE is equipped with a mine plow and is carrying two ‘maxi-pipe’ fascines. Illustration produced by Jarosław Janas, funded by our Patreon Campaign.