Just been looking at a map 1896-1900 and was interesting to see how much land Cammell Lairds seemed to have reclaimed from the MERSEY

in last pic I've circled roughly where the tannery was

Derek, if your referring to the top of the Google map as dock, that was the Basin, the water levels were as far as i remember,they were controlled by pumps, as far as the tide goes, if you look at the slipway that the big construction hall is at the top of, you can see the tide line, even at the highest spring tide the water would not pass half way up that slipway.