Ruakanakana Pass

Safety first – new rail, re–routing the Main North Line

Tar Barrel Tunnel, (also known as Tunnel 21) lies between Kaikoura and Blenheim on KiwiRail’s Main North Line, just south of Ward. It was severely damaged by the Seddon and Kaikoura earthquakes and HEB has been helping to renew and rebuild it – keeping people, trains and motorists safe in future.

We recently completed building a rail bypass, shifting a 1km section of track, and replacing the 167m long Tar Barrel tunnel.  Built in 1913, it’s the oldest in the Main North Line.

It’s complex, State Highway 1 travels over the existing tunnel, and so construction is happening in a live road and rail environment.

Our work

Building – a new 100 metre long rail underpass structure and approach retaining walls, crossing beneath State Highway 1.

Rebuilding – one kilometre of rail track through a new cutting requiring removal of approximately 450,000 cubic metres of material.

Re-aligning – State Highway 1 needed to be re-aligned to accommodate the works, while the road overpass is being built.