Weholite helps realise Hull's renewable energy vision of the future

The expertise and engineering vision of Newport based large diameter plastic pipe manufacturer Weholite has played an integral role in the creation of a new world class centre for renewable energy in Hull.

Green Port Hull is a collaboration between Hull City Council, East Riding of Yorkshire Council and Associated British Ports to promote investment and development of the renewable energy sector in the Humber region and to secure long-term economic growth for the area.

The vast 500 hectare quayside development takes full advantage of the Port of Hull’s prime location in relation to the offshore wind opportunities in the North Sea. The port is within 12 hours’ sailing time from three major Round 3 wind farm zones.

As a result, the region is perfectly placed to capitalise on the UK’s offshore wind industry and this key attribute is the reason that engineering giant and renewable energy specialists Siemens has chosen the port as the location to build its world class offshore wind turbine blade manufacturing, assembly and servicing facilities, which will form the centre piece of Green Port Hull.

The new Siemens factory is being built in the Alexandra Dock, an existing port facility in the heart of the substantial development that will be completely transformed to Siemens specifications.

Associated British Ports awarded the approximately £100 million contract for dock civil engineering work to a joint venture of GRAHAM and Lagan Construction Group, with CH2M Hill as consulting engineers. Official ground breaking took place in January 2015.

Preparation of the site required infilling one third of the Alexandra Dock with approximately 780,000m3 of material and the reclamation of 7.5 hectares of the river by dredging 62m wide and 11m deep berths, to create a new 650m quay wall to accommodate 3 offshore wind turbine installation vessels.

Construction will also involve dredging a new berth pocket, completion of earthworks and surfacing, building internal access roads and service networks, construction of a new roll-on/roll-off ramp and the demolition of some existing buildings.

In order to ensure the newly reclaimed and infilled land of the Alexandra Dock remains consistently well drained in the future, GRAHAM Lagan Construction Group JV, recruited Asset International to provide a range of drainage solutions to facilitate general surface water drainage, as well as storm water events where large amounts of water may fall on the site in short periods. Another consideration was managing the flow of potentially large amounts of water that would run off the vast roofs of the Siemens factory buildings during rainfall.

On an already complex site another one of the key issues that the specialist Asset design team needed to overcome was to provide a solution to withstand the abnormally high loading conditions caused by the giant wind turbines that were being installed adjacent to the pipelines.

Asset’s solution was to provide approximately 2km of their patented Weholite large diameter HDPE pipe. The diameter of the pipes supplied ranged in scale from 400mm to 750mm to facilitate the diverse requirements of different sections of the site.

The pipes were delivered to the site in 14 metre lengths, before being welded together in strings of approximately 100 metres, whereupon they were craned into prepared trenches, which had been dug in the newly infilled, largely sandy ground.

Weholite pipes were chosen for this project over other drainage solutions due to the fact that the contractor was looking for a product that would manage well in an unusual and often unsound environment. The product needed to be flexible enough to allow for land movement, but strong enough that it would not buckle or crack. Concrete was immediately deemed unsuitable due to its inflexible nature and many other plastic drainage products were also ruled out as their joints are not flexible enough.

Asset supplied the perfect solution by delivering a full penetration external weld in order to provide a strong connection between each pipe. The design overcomes settlement issues as the pipe will flex as one homogenous system as the land moves around it.

In addition to the 2km of pipe, Asset also provided fifty custom built individual man hole chambers, complete with benching, ladders, stubs and lifting eyes, which were all completely pre-fabricated at the company’s south Wales factory and delivered to site in Hull fully constructed, saving valuable time on the ground.

The bespoke chambers were the first to be built utilising Asset’s new fully computerised robotic milling machine, which has already increased productivity by 40%, not to mention improved the precision and reproducibility of the milling tasks – which until now were carried out exclusively by hand.

Speaking about the project, Matthew Thomas, technical sales engineer at Asset International commented: “Working on a landmark project of such scope and ambition was as challenging as it was rewarding. The size of the Green Port site, along with the demanding land conditions, certainly allowed us to flex our engineering expertise and provide our client with a bespoke Weholite solution that ticked every box.”


The new Simens site is due to become fully operational by summer 2017.