The NCTIR project has a large number of upslope works directly above the Main North Line (MNL) rail. In many cases these works require scaling to remove loose rock which has the potential to damage the rail track when it falls on the line. In normal operations this would require over ballasting whereby ballast or hard fill is placed over the line to protect it from impact damage. This takes time and is not quick to install or remove. The NCTIR construction teams needed to find a way to speed the process up and improve the efficiency.
As part of the NCTIR project, there are large amounts of W beam to be replaced and new sections installed. The team approached KiwiRail to gain approval to use W beam as a means of protecting the rail during scaling operations.
Estimated results and savings
The use of W beam resulted in quicker installation of protection and is cheaper as it avoids the need for excess over-ballasting, with cost savings estimated at $1,000 per day of scaling works. No trucks or excavators are required, with the W beam simply lifted into place by two people making it quicker to install and remove. The guard rail has ropes tied to either end to make lifting easier and safer.