Client name: KiwiRail

Duration: 2010-2011

Location: Wellington, New Zealand

Coffey worked with KiwiRail to deliver rail upgrade works on time and without incident or interruption to existing operating schedules.  

Increasing the speed of a single track rail line in challenging landscape

The North South Junction is located between Pukerua Bay and Paekakariki, and consists of 3.25km of single track on the North Island Main Trunk Line. 

Our client sought to improve their operational capability by increasing the rail line speed from 40 km/h to 70km/h – this required extensive tunnel lowering and strengthening.

The rail alignment also runs through a challenging landscape where rock falls are a frequent occurrence, causing safety concerns for commuters and schedule delays. 

KiwiRail wanted to continue operating to a ‘business as usual’ schedule. We needed to ensure upgrade activities would progress on time and without compromising the safety of employees and contractors.

Lowering of tunnels, rock bolts, rockfall netting and retaining walls

KiwiRail scheduled a two week line closure over the Christmas period to minimise disruption to the public. We project managed the lowering of four tunnels totalling 861m in length, after anchoring 1670 rock bolts to provide additional strength.

To reduce the risk of slope failure, we oversaw the installation of more than 8600m2 of anchored rockfall netting and retaining walls. This reduced the risk of rock falls to provide safe passage for trains and commuters.

To ensure timely delivery of scheduled works during the line closure, we introduced performance incentives with our main contractor. These included variable payment components for quality, timely delivery and safety considerations. 

The upgrade works were delivered in a live rail environment, including night conditions. Tight coordination and monitoring of all activities ensured our teams met critical milestones in terms of safety, time and costs.

Rail upgrade works delivered on-time and without public disruption

The rail upgrade has allowed our client to deliver faster freight and passenger travel times. The reduced incidence of slope failure ensures safe passage and fewer delays.

This project was awarded the RTSA 2012 Biennial Railway Project Award, and was acknowledged as a finalist for the NZ Engineering Excellence Awards 2012.