The Portrack viaduct crosses the river Nith in Dumfreshire carrying the Glasgow-South West Scotland line. The bridge, including approach spans is 200 metres long with a 90 metre curved truss its centrepiece.

Tension control bolts were used because Rowecord and Carillion were working in an environmentally sensitive area. The design had to be quick, safe and easy to build and had the added pressure of working to a tight deadline alongside a live railway.

Photo by Galina Walls -

Greenkote® anti-corrosion protection

Tension Control Bolts Ltd has its own metal coating plant producing an environmentally friendly anti-corrosion coating called Greenkote, which is comparable to galvanising, although it is harder wearing and readily accepts all paint systems. Learn more about Greenkote.