This dredger is shown Moored at Thornaby. When I first acquired the photo I spent some time trying to identify the craft but without success. All I could make out from the original picture was what I took to be the port of registry it the stern but only the letters 'SEA' were visible and I took it to be part of the name 'Swansea'
This morning suffering from insomnia as I often do, I was looking through my collection and doing a little research when quite by chance I came across a reference on the Scottish Built Ships site, to a dredger for the Swansea harbour authority by the name of Abertawe built by William Simons in 1875. at the bottom of the page was a note.
Vessel history
05/1891-11/1892 hired by the Tees Conservancy Commissioners for £60 per week
Problem solved !