Coal Drops Yard, London

Described as one of the largest regeneration schemes in Europe, it will include 50 new buildings, 2,000 new homes, 20 new streets and 10 new public squares spread over 67 acres. Main contractor BAM is employing an array of different skills for this conversion project, from specialist restoration work of the brickwork and ironwork, to repairing the original timber roofs. However, possibly the most challenging aspect of the project is the construction of a steel sculptured roof, which will straddle some of the area between the two original coal drop buildings.

The roof structure is approximately 75m-long on one side and 65m-long on the other. It curves inwards, from the south and north ends, and then rises up in the middle to a maximum height of 25m. Two ‘ribbon’ trusses, sat atop of each building, help form the undulating shape of the roof structure. A series of temporary trestles was installed to support the truss segments during the erection sequence. The trestles will remain in place until the roof structure and its supporting steelwork is complete. Above the trusses the new roof is primarily supported by a compression-tension system, spanning the distance between the Coal Drops buildings. This is supported on new steelwork at each end within the east and west buildings. At the middle point of the roof, there is a large kink where the two sides nearly meet. This area has been dubbed the ‘kissing point. The roof steelwork is doing two jobs, as well as spanning the void between the existing buildings, it also supports a new column-free upper level of the development. The steelwork programme for the Coal Drops Yard scheme is expected to be completed by August, and the new King’s Cross retail destination will open in October 2018.