The biggest complication in this project was the history of the wharf itself: it was built at the end of the 1800s and then altered during a reconstruction project in the 1940s. During these modifications, the mooring mechanisms that allowed the wharf to remain steady even as the river flows around it had been buried. That complicated the works because in order to lower the North-East corner, it was necessary to dig out the anchors - but in doing so, the soil would become unstable. Therefore, before the digging could begin, it was crucial to stabilize the soil.
It was this North-East corner in particular which posed the greatest challenge and required the most ingenuity. The construction of the below-water wharf wall, however, that required both creativity and extraordinary precision. It had to be designed so that it could be constructed sight unseen underwater, where visibility is massively impaired.