Dennis Rock Carling

Dennis Rock Carling

Dennis Rock Carling (1906-1992) trained as a locomotive engineer and spent much of his working life with the London and North Eastern Railway (LNER). In 1939, due to the outbreak of war, Carling was transferred on loan from LNER to the Admiralty to join their Scientific and Technical Pool. Dennis Rock Carling was a Graduate, Associate Member and then Member of the IMechE.


Carling studied Mechanical Sciences at Cambridge University after which he trained with Beyer, Peacock and Company locomotive manufacturers. In the early 1930s Carling took a sabbatical to visit locomotive builders around Europe before returning to take up a post with LNER as the Technical Assistant to the Chief Test Inspector in the Chief Mechanical Engineers Department.

In this role Carling worked mainly on locomotive testing in the Dynamometer Car Office. Appearing similar to a standard railway carriage the dynamometer car enabled the performance of a locomotive to be scientifically measured allowing the data to be interpreted with a view to making improvements and efficiencies to locomotive design and operation.


With the Admiralty Carling initially worked on testing the protection of ships against magnetic mines before being transferred to the Torpedo Experimental Establishment (TEE) research department in 1943. TEE were responsible for the design, development and production of Royal Naval torpedoes.

With the TEE, Carling was able to draw on his experience of testing gained through his work with dynamometer cars to use in his role in testing newly developed gyroscopes to be used in Navy torpedoes. Gyroscopes provided a direction reference for torpedoes once they were launched.

Intelligence gathering in Germany

Towards the end of the war Carling was granted a protective temporary commission into the Royal Naval Volunteer Reserve to investigate aircraft torpedoes.

This position allowed Carling to act as an investigator for the Combined Intelligence Objectives Subcommittee (CIOS) – whose function was to “investigate the research and development carried out at nominated targets.” In reality these “nominated targets” were German factories and associated individuals. The intention was to gather information and intelligence which would further the Allied understanding of technical developments into weapons development. Specialists such as Carling would interview German engineers and scientists with whom they shared a specialism.

Press cutting reporting on British demonstration of German advances in torpedo development [IMechE Archive CAR/1/7]

Railway imports

In addition to interviewing German scientists and engineers, Carling was also responsible for assisting with the import to Britain of chemicals from Germany to aid torpedo development. Here, the link to Carling’s locomotive background is apparent. He reported on having identified suitable wagons for transporting H2o2 (wagons were required to have an aluminium rather than steel cistern) and provided information as to the number of wagons, their locations, condition and need for alteration to run on British railway lines or repair.

[IMechE Archive CAR/1/1]