London schoolboys among the ' Kings ' special tour of Swindon locomotive works . Boys from many of the London technical schools left the realms of theory and models and had an opportunity of really seeing what makes the railway wheels go round when , on schoolboys day , they toured the huge locomotive works of the Great Western railway at Swindon . Under the guidance of experts , the boys toured the shops and watched the building of locomotives from the little tank engines , railway ' maids of all work ' , to the record breaking King and Castle class giants . Every phase of locomotive manuafacture and main chance was shown to the boys . 17 April 1936