Flood defence ‘Ipswich Tidal Barrier’ at the British Eastcoast is part of the Ipswich Flood Defence Scheme and will protect some 1,600 homes and 400 businesses in the Ipswich area from flooding during extreme water levels over the next 100 years. The entire project involves an investment of 67.4 million British pounds, making it the largest investment that Ipswich has made in the past 20 years.
The VBA consortium, Volker Stevin – Boskalis Westminster Ltd – Atkins, has been awarded the contract for the construction of the protection works for the seaport area, consisting of quay walls, retaining defences for the harbor and estuary and the associated control building. The project was carried out by a joint venture VBA, consisting of: Volker Stevin, Boskalis Westminster Ltd. and Atkins. As a consultant and contractor to VBA, Hollandia Infra was responsible for the fabrication and installation of the so-called “Rising Sector Gate”, the movable steel barrier measuring 23 meters wide and weighing 192 tons.
VBA designed the RSG, Hollandia Infra was asked as a consultant to contribute Dutch knowledge and expertise to the design process.
The Rising Sector Gate is a water flood defence consisting of a semicircular door that rotates vertically on its axis. This door is usually turned downwards – in a recess in the concrete river bed – so that shipping has free passage. When there is a threat of high water, this door turns 90 degrees upwards from the bottom on 2 arms and thus blocks the passage.
Hollandia Infra has converted the design of this 192-tonne barrier into workshop drawings. The radial door is 23 meters wide and has a 9 meter retaining height and a maximum internal height of 1.9 meters.
In addition to the door construction with pivot points, Hollandia also produced the semicircular steel door frames that were poured into the concrete of the quay wall by the main contractor within the tight tolerance. The active rubber sealing profiles ensure that the door construction is closed within these frames.
In November 2017, the entire construction was transported from Krimpen aan den IJssel to Ipswich by pontoon and mounted in the passage with a 600-ton crawler crane. A nice film has been made of this.
The Ipswich Tidal Barrier was officially opened on Friday 8 February 2019. The opening ceremony was attended by various representatives of the local authorities with the compliments for the “Dutch steel builders of Hollandia”.