Dennis Rock Carling was a locomotive engineer, who was also involved in World War II work for the Combined Intelligence Objectives Sub-Committee.
Having studied mathematical and mechanical science at Cambridge University, Carling went to work at Beyer, Peacock and Company in 1928. He then joined London and North Eastern Railway (LNER) as Technical Assistant to the Chief Test Inspector in the Chief Mechanical Engineers Department. He worked mainly in the Dynamometer Car Office on locomotive testing, with some work undertaken in Motive Power Department and in the workshops. After the War he returned to the company before taking over the running of the Locomotive Testing Station (LTS) at Rugby where he remained until retirement (apart from a period of secondment to Office de Recherches et d'Essais).
His slides were used in lectures, mainly about the LTS and Garratt locomotives - the descriptions come from his slide notes.