The file consists of of correspondence between the Engineer to the Humber Conservancy Board (Arthur Ernest Butterfield), contractors, and the light keepers for the North and South Killingholme lighthouses. The subject matter is the maintenance of these lighthouses. This includes returns of the following forms: Form A 'New Articles Required', Form B 'Stores in Stock', and Form C 'Report of Stores Received'. It also includes monthly postcards sent from the Light Keepers to the Engineer reporting the paraffin consumed and in stock at the lighthouses.

The correspondence includes an exchange between the Engineer and George Wragg Limited, Manchester, regarding the redecoration of the Humber Conservancy's Board Room, including the installation of oak fittings. It also includes secret correspondence with Captain J. W. Barr, Officer i/c E.L. & T. Humber Defences, in connection with a proposal for the installation of a searchlight to one of the Killingholme lighthouses.