Rapid fire

A fuller insight into the development of the UK ATP and the people who contributed to its successful development and supply

I was surprised at the content of the 'Rapid fire' article. In it you state that the ATP System was designed and built by Babcock.

The concept of the ATP was first developed by the Americans, the Mk 17 & Mk 19, and the MoD obtained a unit for trials. When this was tested the actual performance achieved fell short of that predicted by the American maker. Engineers led by Norman Bolton at the National Engineering Laboratory at East Kilbride were commissioned to see if they could develop a transient performance model for the pump geometry that would accurately predict that measured in testing. Mr Bolton’s team achieved their aim, developing a mathematical model which accurately predicted the transient performance of the unit. Mr. Bolton’s team were then commissioned to do a survey to find out if British Industry had the resources to design and manufacture a ‘British’ ATP. This lead to a specification and invitation to tender being prepared and this was sent to both Individual British firms and Consortia seeking quotations for the design and development of an ATP then building a Prototype which would be tested to see how well the selected unit performed against the Mk 19 machine.

A team from Weir Pumps at Cathcart in Glasgow, led by Mike Ryall their Technical Director, won the contract to design and build the UK ATP. Working in conjunction with the Mr. Bolton’s team at NEL and a team, Drs Gilchrist, Lee and Carey from Strathclyde University, who developed a transient analysis of the Air Turbine to drive the pump, Weir Pumps drew up the design of their ATP and built the prototype unit. Because of the transient operation of the unit, it completes its task within 0.8 seconds of pressing the Firing Button; many components within the overall design were tested independently to validate their fitness for this unusual application.

Weir Pumps built a dedicated test rig at Cathcart, to prove the Prototype Unit before it was sent to the MoD for acceptance testing. By combining the transient performance models for the air turbine and the pump, the performance of the complete unit could be predicted under a variety of operating scenarios. Messrs Strachan & Henshaw had developed the novel Programmable Firing Valve which could ‘shape’ the lift vs. time operating profile of the valve. When this ability was married to the ATP model, the operation of the ‘launch system’ could be optimised so that it could safely launch many different weapon types.

Following successful testing of the prototype I believe eight units were ordered with a view to fitting them in the ‘Upholder Class’ submarines but this never happened. Later Strachan & Henshaw took over responsibility for the weapon system. I believe that later Babcock assumed responsibility.

I trust this brief history gives you a fuller insight into the development of the UK ATP and the people who contributed to its successful development and supply.

Hector M.K. Dickson

Next letter: Apprenticeships and colleges of advanced technology