The South East England Substations Alliance (SEESA) was a joint venture by firms including Areva, Mott MacDonald and Skanska. With a planned 10-year timeframe from 2006 to 2016, SEESA would be responsible for the design, management, planning, construction and commissioning of both 400kV and 132kV substations across the South East of England.
The object of the venture was to upgrade and renew a major part of the UK’s power transmission network, ensuring its safety, longevity and capacity as demand on the network increases. SEESA’s projects included heavy foundations, the construction of service infrastructure, a variety of major building works, and the provision of building services.
SEESA approached us to provide a transformer barrier at their 400kV substation in Barking, Greater London, in order to protect equipment and personnel from the transfer of heat and fire. This older site was in the process of renovation, with plans to build another neighbouring site to cater to growing demand in the capital.
The height of the barrier meant that it would have to be wind resistant, while the barrier would also have to be extremely durable. Given the importance of the site and the demands placed on it, as well as the necessity to shut down power in order to conduct maintenance, a long-life coating would be required.
Due to height of the barriers, a specialist crane contractor was appointed to manoeuvre the structural steel into position, requiring the use of fixed scaffolding. A National Grid approved standby man (provided by SEESA) was also required to oversee the works and ensure that they were conducted safely.
As a National Grid site, our Durasteel engineers needed to be BESC-trained personnel, with the work coming before the 2020 revisions to the National Grid Electricity Contractors Scheme. Most crucially, Invicta would have to work to a tight programme, as the project would take place during a planned power outage at the substation.
To accommodate for the unique fire and wind loads – as well as the corrosive environment – Invicta coordinated a bespoke design report from an independent structural engineer. Following client approval, we then engaged a structural steel specialist to manufacture the required support steelwork, as designed by our chosen independent structural engineer.
In order to protect against corrosion effects in this C3 environment, we opted to deploy a coating with a life of 40 years, with a life to first maintenance of 20 years, meeting the requirements of ISO 12944. The Durasteel panels were prepared offsite with the initial paint coats, with final coats being applied on site once the barrier was installed.
Invicta successfully installed the 30m x 9m transformer barrier in five weeks with eight personnel, including a team of specialist painting contractors, crane slinger signallers and Durasteel operatives.
The installed barrier was signed off and certificated as per the design report and client’s specification, and stands as both an aesthetically-pleasing and functional fire protection system, painted to RAL colour 7012 – a neutral Basalt Grey.