26 Oct Our Chieftain’s Restoration is Complete!

The Chieftain FV4201 was the main battle tank of the UK during the 1960s, 1970s and 1980s. A development of The Centurion and as regular visitors to our blog would know, therefore a continuation of the British cruiser series, the Chieftain shares many commonalities with both its predecessor and successor.

Our Chieftain arrived at Armourgeddon back in September 2015. What we expected to be a 6-month job has been quite the restoration project taking a total of 13 months to complete. However, she is now our pride and joy, adding to the main battle tank collection we house in the Armourgeddon museum and military vehicle collection.

Today, as we write, the Chieftain has made its final trip out of the workshop at Armourgeddon having completed its restoration process. A complete vehicle strip, not just of the engine but all of the paintwork with a needle gun, testing of the major working parts and then the time consuming reconstruction process was embarked upon.

Considered as the most formidable main battle tank in the world, with the most powerful main gun at the time of its introduction in 1966 and most effective armour of any tank any made, the Chieftain has quite some reputation.

The Chieftain introduced a supine driving position- reclining backwards, for the first time to the development of tanks. This position enables a heavily sloped hull with reduced height. A tank faster than the Centurion and able to maintain its speed longer than the Leopard I and able to out-gun its contemporaries, the Chieftain was also the first tank to enhance its amour, which was already superior to many of others.

The Chieftain came from a company called Bastion. They are the makers of a specific type of sand bag and mesh wall system. It’s that type of wall, which encompasses the periphery of the UK forces base in Hellmand Province, Afghanistan, hence the name Camp Bastion.

The tank was expected to be able to engage the enemy at long range, from defensive positions, and be able to handle medium artillery. To this end, the gun angle of depression more than the 8 degrees of Conqueror and would be equipped with better frontal armour. The tank was expected to achieve a firing rate of 10 rounds per minute in the first minute and six per minute for the following four. Quite a step change on previous tanks of its size.

The first few prototypes were provided for troop trials during 1959. These trials identified a number of changes that were needed. Improvements to address engine vibration and cooling resulted in redesign of the rear hull. This increased the design weight to nearly 50 tons and accordingly the suspension (which had been designed for 45 tons) was strengthened. Track pads had to be fitted to protect roads from damage and the ground clearance increased. The design was accepted in the early 1960s.

Britain and Israel had collaborated on the development in its latter stages with a view to Israel purchasing and domestically producing the vehicle. Two prototypes were delivered as part of a four-year trial. However, it was eventually decided not to sell to the Israelis due to the political alliance with the Arab States and Jordan at the time. This, of course, prompted the Israelis to follow their own development programme.

In 1957, NATO had specified that its forces should use multi-fuel engines. The early BL Engine delivered around 450 bhp (340 kW) to the sprocket, which meant a top road speed of only 25 mph (40 km/h) and cross-country performance was limited. This was further hampered by the Horstmann coil spring suspension, which made it a challenge to drive off road and provide the crew with a less than comfortable ride to say the least. Due to the cylinder linings being pressure fitted, coolant leaks within the cylinder block were common, resulting in white smoke billowing from the exhaust.

In the late 1970s, engine design changed with the introduction of Belzona, which was used to improve the lining seals. Engine output also increased, with later engines delivering some 850 bhp (630 kW) to the sprocket. This meant better performance and an increased speed with cross-country capabilities improved too.

Chieftain proved capable in combat and able to be upgraded with enhancements, both for overall improvement and to meet local requirements. The tank continued to be upgraded until the early 1990s, when Challenger 1 replaced it. The final Chieftain version, which was used by the British Army until 1995, incorporated “Stillbrew” armour named after Colonel Still and John Brewer from the Military Vehicles and Engineering Establishment (MVEE), the Improved Fire Control System (IFCS) and the Thermal Observation Gunnery (TOGS). The last British Regiment equipped with Chieftain was the 1st Royal Tank Regiment, which was based at Aliwal Barracks, Tidworth.

It was in the Middle East that the Chieftain was to see all of its operational experience. First, it was used extensively by Iran during the Iran-Iraq War of 1980–88, including the largest tank battle of the war, with mixed results as many suffered from chronic engine problems. The Chieftain remains in service in Iran, the Mobarez tank being a locally upgraded version.