A 3D CAD model of the dam designed in SolidWorks software by myself courtesy of Rota Design Limited. The OS map is overlaid and the dock has been modeled in grey; the dam infill also follows the OS survey map and for reference, the original location of the pontoon is indicated in dark grey. The pontoon has its wall and deck fittings removed and is sunk on the floor of the dock vertically below its approximate working location. [108]

For some sad reason, I decided to estimate the quantity of rubble and infill that had been used to build the dam. I modeled the dam using scaled dimensions from the OS map of 1970-74. The assumed mass density of the rubble is 2,320 kg/m3 with an estimated angle of repose of 45 degrees and an average depth of 47 feet (14.3m); the dock wall on the north side was originally constructed to this depth.

The mass properties of the model reveal that nearly 130,900 cubic metres of infill would be necessary to build the dam which probably weighed in excess of 300,000 tonnes. The unknowns are the actual topography of the dock floor, the compaction level of the rubble, the depth at the quayside and the effects of saturation. I feel sure that a civil engineer will correct my estimation but as one irritated production operative once shouted at me and said "in this company, there's no such thing as a civil engineer!"