These pages are dedicated to the Deltic locomotive's classified and unclassified works visits, by clicking on the yearly links above each time-line is accessed giving accounts of when each locomotive was on works. The vast majority of works visits took place at Doncaster and are colour coded into the classified/unclassified repairs, other works visits are merely colour coded into the location as these would of been mainly Unclassified repairs only.

Little information exists as to when construction of each locomotive began, however, it is assumed that an average of six months per loco was required once production was into full swing. Certainly as many as eight examples have been recorded under construction at Vulcan Foundry at any one time.