This was possibly one of our biggest challenges to date. We were approached by the Structural Engineers that had been tasked to design the civils works for a Hydroelectric turbine installation on an island, with no access to in, in a navigable section of the river Trent.
The challenges we had to overcome were not just the fact that we would be working to depths of 4 metres below river bed level on a tiny island, but that we had to gain access to the island for all the heavy plant and machinery needed for such a construction. Huge cranes and piling rigs needed to get on to the island that was inaccessible other than by a footway over a lock that was 9 metres wide.
We first came up with our own design for a Class A bridge that was retractable. We designed and fabricated the bridge and its mechanism for cantilevering out over the river. The system had to be robust and operate swiftly as at times we would have to pull the bridge in and out half a dozen times a day, for us to gain access and for boats to pass by.
Despite all its challenges the civil works were completed on time. It was a fascinating project that involved damming the river, managing flood levels that rose and fell by three metres or more and constructing complex structures within the extremely tight confines of the site, craning in huge items of heavy turbine machinery as well as sluice gates and screens whilst preserving features of historical interest.
The work on site took 15 months to construct and was completed in January 2016.