The file consists of 'general' correspondence, sent (and received) by the Engineer to the Humber Conservancy Board (Arthur Ernest Butterfield), to/from the Institution of Naval Architects, the Engineer-in-Chief of the Mersey Docks and Harbour Board, and others. The subject matter is the nautophone fitted on the Spurn Lightship [HCB LV 12] for use in foggy situations. This includes particular discussion surrounding Mr Butterfield's disappointment with the nautophone's performance.

Also included in the file is a report sent from the Mersey Docks and Harbour Board on the progress of dock works at Liverpool.