Having studied mathematical and mechanical science at Cambridge University, Carling went to train at Beyer, Peacock and Company in 1928. Some of Carling's autobiographical writings suggest he also had a period working for Hunslet.
He then joined London and North Eastern Railway (LNER) as Technical Assistant to the Chief Test Inspector in the Chief Mechanical Engineers Department (CAR/2). 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 at Rugby (CAR/3) where he remained until retirement - apart from a period of secondment to Office de Recherches et d'Essais (ORE). In retirement (CAR/4), Carling was an avid researcher and writer who published many papers and a book on tender locomotives. He was active in both the Newcomen Society and Institution of Mechanical Engineers (IMechE). Some items relate to his wider interests and family (CAR/5).
The collection has been arranged by activity ie material is arranged by who Carling was working for when it was created, by his personal railway research and by his personal items, not related to railways.