Liquid propellant 20 pdr

Meanwhile work had begun on developing a successor to the Centurion, with the challenge of producing a vehicle that had the firepower and protection of the Conqueror but within a smaller, lighter platform. The army defined initial requirements for the new tank (Medium Gun Tank No. 2) in 1951 and Chertsey started to investigate concepts. Some work was undertaken on a ‘cleft turret’ concept, which dispensed with a mantlet and enabled a lower turret. In 1953 it was decided to investigate the use of liquid-propellant guns, but this approach was soon rejected and in 1954 it was proposed that a concept be developed based on a 105mm gun using bagged charges. The weapon requirement was then revised and the decision made that it should be a 120mm gun. This decision followed an assessment of the required performance to defeat an internationally agreed armour target designed to represent postulated future Soviet tanks. The work on the 105mm gun using bagged charges had shown promise and so was taken forward as the starting point for the new 120mm gun on the basis that it would save weight over more conventional gun designs. Meanwhile Chertsey had looked at a novel approach to minimising height – the use of a prone position for the driver. In 1956, to assess if this was feasible from an operational perspective, a test bed, designated FV4202, was built based on Centurion components. It had a meteor engine and mounted the 105mm bagged charge gun in a cleft turret and is sometimes referred to as the 40-ton Centurion.

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Another concept that reflected a lot of the thinking from the Contentious studies was a Liquid Propellant (LP) gun concept. This had a two-man crew and like Contentious had a limited traverse gun. Unlike Contentious, gun elevation was achieved through elevating the complete crew compartment, which was a separate pod. A large-scale model of the concept was made and some forty years later, in the 1990s, this model was brought out of store when a team from RARDE at Fort Halstead visited Chertsey. They had come to argue a case for funding to undertake some concept design work for a liquid-propellant gun tank, claiming no work had been done. After their pitch the model, which had been hidden under a sheet, was revealed. It was pointed out that the main reason the concept was not taken forward in the 1950s – namely the highly corrosive nature of the propellant – had still not been addressed and so further concept work would be nugatory. This did not stop the Guns Division at RARDE from continuing to work on LP guns and concepts and only stopped after encountering ‘unexplained events’ with the propellant.

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Abraham Gubler said:

The book “The Tank Factory: British Military Vehicle Development and the Chobham Establishment” by William Suttie has the following mention of the liquid propellant 20 Pounder:

Meanwhile work had begun on developing a successor to the Centurion, with the challenge of producing a vehicle that had the firepower and protection of the Conqueror but within a smaller, lighter platform. The army defined initial requirements for the new tank (Medium Gun Tank No. 2) in 1951 and Chertsey started to investigate concepts. Some work was undertaken on a ‘cleft turret’ concept, which dispensed with a mantlet and enabled a lower turret. In 1953 it was decided to investigate the use of liquid-propellant guns, but this approach was soon rejected and in 1954 it was proposed that a concept be developed based on a 105mm gun using bagged charges. The weapon requirement was then revised and the decision made that it should be a 120mm gun. This decision followed an assessment of the required performance to defeat an internationally agreed armour target designed to represent postulated future Soviet tanks. The work on the 105mm gun using bagged charges had shown promise and so was taken forward as the starting point for the new 120mm gun on the basis that it would save weight over more conventional gun designs. Meanwhile Chertsey had looked at a novel approach to minimising height – the use of a prone position for the driver. In 1956, to assess if this was feasible from an operational perspective, a test bed, designated FV4202, was built based on Centurion components. It had a meteor engine and mounted the 105mm bagged charge gun in a cleft turret and is sometimes referred to as the 40-ton Centurion.

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And later in relation to the Contentious:

Another concept that reflected a lot of the thinking from the Contentious studies was a Liquid Propellant (LP) gun concept. This had a two-man crew and like Contentious had a limited traverse gun. Unlike Contentious, gun elevation was achieved through elevating the complete crew compartment, which was a separate pod. A large-scale model of the concept was made and some forty years later, in the 1990s, this model was brought out of store when a team from RARDE at Fort Halstead visited Chertsey. They had come to argue a case for funding to undertake some concept design work for a liquid-propellant gun tank, claiming no work had been done. After their pitch the model, which had been hidden under a sheet, was revealed. It was pointed out that the main reason the concept was not taken forward in the 1950s – namely the highly corrosive nature of the propellant – had still not been addressed and so further concept work would be nugatory. This did not stop the Guns Division at RARDE from continuing to work on LP guns and concepts and only stopped after encountering ‘unexplained events’ with the propellant.

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There is also a picture of the later LP concept.

This book (The Tank Factory) is a great resource on British tank development. It doesn’t answer every remaining question on this topic but it comes close.

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Abraham Gubler said:

This book (The Tank Factory) is a great resource on British tank development. It doesn’t answer every remaining question on this topic but it comes close.

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