The authors of Tidal Lands (s.p.b.s) write of ‘keying up’ in connection with the reinforcing of the seaward flood bank slope with blocks of stone, usually chalk in this region, sometimes other more available stone elsewhere. The skill of the worker(s) was to not just dump the stone from the barge on the side of the slope but to ‘man-handle’ the blocks so that, as far as was possible, they fitted together. Sometimes, according to the authors, the stone blocks were then ‘grouted’ in cement and given a smooth surface. Locally, after the 1953 floods, the seaward face of the flood banks (once repaired) were keyed up with stone slag from Scunthorpe steel works and this then grouted and bonded with some sort of black mastic which, in most places, has held in place to this day.
The essay on Geology (see Publications/pdfs) includes three black-and-white photographs kindly donated by an elderly lady in the Netherlands. They relate to when her father and other Dutch flood defence workers were brought to north Lincolnshire to employ their expertise in reinforcing the south Humber bank. The authors of Tidal Lands credit such Dutch workers with great skill and knowledge. The book gives complex examples of how Dutch workers created ‘fascines’ and then bound they together to create huge ‘mattresses’ which, when sunk into the foreshore by a loose stone overburden, protected the base of a clay bank flood defence from the full force of the tide. One of the three pictures in the pdf shows the Dutch workers with some prepared fascines. The picture above shows a scene near a large sluice in the Netherlands where mattresses have been manoevered into place and surrounded by stone-laden barges ready for their cargo to be transferred to the mattresses.
I do not know exactly at what point along the south Humber bank the Dutch workers were deployed but I think it was west of South Ferriby in Winteringham parish.
(To be continued).