St Margaret’s Head Tunnel

Originally built as part of a passenger route in 1877 St Margaret’s Head Tunnel, which is located close to the north approach to the Forth Road Bridge, has been closed since 1954 when it was only used to transport coal and freight between North Queensferry and Rosyth.

In early 2018 Millar Callaghan were involved in the project to strengthen the area by infilling the tunnel and permanently sealing it off. The internal surface of the tunnel was lined with a damp course membrane before high-density polystyrene blocks were cut to shape to neatly fit the profile of the internal arch. The polystyrene blocks were then tightly packed into the tunnel. This process was repeated with 21,342 blocks until the tunnel was entirely filled. With the internal works complete, a convoy of trucks then arrived on site to poured concrete down a manhole located on the road above the tunnel. In May 2018 after 8000 manhours of work the tunnel was completely sealed off.