Liquid propellant 20 pdr

[Charlesferdinand]

In his recent book 'Tanks' Richard Ogorkiewicz briefly discusses experiments with liquid propellants. Apparently a version of the 20 pdr with liquid propellant was built, which used red fuming nitric acid. This seems to me a thoroughly nasty substance to have inside a tank.

Does anyone know how this was supposed to work?

Ogorkiewicz adds that at one point a LP gun was included in the design for the Chieftain, until sanity prevailed.

 

[Old_ROF]

Not sure if you've found anything yet but there are a couple of reports held within the DTIC system which were generated by A.R.D.E in 1956 from the work they were doing. These are progress reports on work being carried out on "Guns using Liquid Propellants".

If you can access the system the DTIC references are A492303 and A492169.

There is also general information contained in "Liquid Propellant Guns" an article/chapter by Morrison, Knapton and Bulman published in the book 'Gun Propulsion Technology' edited by L. Stiefel as part of the Progress in Aeronautics and Astonautics Series. Published around late seventies / early eighties I think.

 

[Abraham Gubler]

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.

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.

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.

 

[jsport]

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.

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.

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.

One good start to not letting all the RLPG research go to waste. Sprays over solids & liquids.
"Additive and a method for improving combustion efficiency and reducing overall emissions of carbon-based combustible materials " ie safe storage before ignito..
US patent 20150020444 A1
mostly likely many other innovations out there.

 

[Charlesferdinand]

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.

Thanks for pointing that one out! As for the 'unexplained events', if Ignition by John Clark is anything to go by, I can imagine how they went.