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Tubes & turning boxes protect Stratford residential scheme

Stratford, London

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Contact Fraser Shearer Sarun Vysakham Ben Tan Azim Rizvi Anand Raghavan Our USA Office

Home Case Studies Tubes & turning boxes protect Stratford residential scheme

Fire Rating

4 Hours Integrity


90m² of Durasteel, 600 linear meters of steel tube

Team Size

4 Durasteel Engineers

Company profile

Halsion is an engineering services company based in Canterbury, Kent. They design and install mechanical, electrical and plumbing (MEP) services, fitting systems such as heating, lighting, ventilation and power as part of their turnkey engineering solutions.

As well as working on iconic Kent buildings such as the Turner Contemporary and Marlowe Theatre, Halsion have a legacy of major construction projects in London and further afield. These include the Battersea Hotel, the Chelsea and Westminster Hospital, the UK Supreme Court and the Old Admiralty Building.


The Challenge

Halsion was contracted to work on Cherry Park Stratford, a major new residential development adjacent to the Westfield Stratford City shopping centre. Halsion primarily approached us to design and install an external tube run from the building to parallel substations. This was necessary as part of the steel tube run was deemed to be totally exposed to external weather conditions, which standard specification steel tubes (EN:10255) are not suited for.

The steel tubes would need to be upgraded to galvanized finished steel tubes with an increased wall thickness. This would allow the tubes to go through the galvanizing process but still meet UK Power Network (UKPN) specifications for seamless parallel threads.

Another challenge came within the substation areas. Invicta was contracted to install Durasteel turning boxes, but these had to be located for the change of directions to service other substations. We also had to consider the high voltage cables leaving each Durasteel turning box, which would have to be terminated on the transformers.


The Constraints

As this was a very long cable pull route, multiple Durasteel turning boxes needed to be introduced. To avoid damage when each cable was pulled through, every steel tube was carefully checked for any internal sharpness or burrs. Each Durasteel turning box location required demountable panels to allow access for the cable pull process, as well as any maintenance or inspection purposes.

Delivery needed to be carefully coordinated and timed with Halsion and Unibail-Rodamco-Westfield. This is so that we could utilise the unloading facilities and correct lifting equipment needed to get all the steel tubes and Durasteel materials to the workplace in each area.

Our designers needed to consider the change in slab heights, keeping the steel tube and turning box level so the smooth cable pull could be successfully executed. To cater for the weight load and steel tube arrangement, the trapeze support also had to be carefully designed.


The Solution

In coordination with Halsion, their architect and the UKPN substation designer, Invicta issued design drawings and planned the turning box locations and steel tube routes, which were agreed to ensure a smooth final sign-off. At different stages along the design process, site meetings and surveys were carried out to check that the design drawings suited site conditions, and that the dimensions were all correct.


The Result

The Durasteel systems were successfully installed, signed off and certificated as per the substation design team’s project requirements, ensuring a successful cable pull and the energisation of the substations.


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