Wellington's passenger rail network would be affected for almost three years following major earthquake
Wednesday, 4 December 2019
Wellington's commuter rail network would be out of action for almost three years following a major earthquake, even after a proposed $100 million upgrade.
A Wellington Lifelines report estimated it would take two years and nine months for the region's passenger network to be fully restored should a 7.5-magnitude earthquake occur on the Wellington Fault.
And that's after a proposed $100m upgrade of structures and slopes along the North Island Main Trunk (NIMT), Hutt Valley and Wairarapa lines to improve the network's resilience.
The upgrade was recommended as part of the $5.3 billion Wellington Lifelines Regional Resilience Project, aimed at reducing the impact of a major earthquake on New Zealand's economy.
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It estimated the region's passenger network would not be fully restored for up to 3½ years should things remain as they are, and for two years and nine months should the upgrade happen.
Entrances to the Rimutaka Tunnel would be heavily affected, and there was no timeframe on when the Rimutaka Hill Rd on State Highway 2 would be able to reopen to motorists.
KiwiRail chief operating officer for capital projects and asset development David Gordon said the timeframes used in the Lifelines Group report were high-level estimates, and averaged out across the region.
Some lines could be affected more than others depending on the nature of the earthquake, he said.
'For example, if the Wellington fault ruptures all the way up the Hutt Valley, then we would expect it would take longer for the railway to be repaired on the Hutt line than on the Kāpiti line.
'Similar to recovery of the railway line after the [2016] Kaikōura earthquake, and depending on the damage and reinstatement works required, we would expect that rail services will be reintroduced in stages.'
That meant a small number of diesel-fuelled trains could resume first, with more added as railway lines were gradually repaired.
Electric-powered trains would probably resume in stages as sections of the overhead power network were restored.
Gordon expected the Rimutaka Tunnel would hold up well in a major earthquake, and that anyone in there at the time would be easily able to get out.
'Although there may be slippages on the steep hillsides leading up to the tunnels, we would not expect them to completely block the tunnel.
'An escape route would be available either on foot or by light vehicle, even if the tunnel was impassable to trains.'
KiwiRail, which is a Lifelines Group member, was also looking at options to improve shipping emergency response times as part of an ongoing ferry and terminal replacement, Gordon said.
It was also looking at terminal and wharf options that would enable transport links to be quickly re-established.
Transport Minister Phil Twyford announced last year the government would pump $193m into the region's rail network to upgrade ageing tracks and infrastructure and increase safety.
Gordon said some of that money could be used for the proposed resilience work, but most of it was intended for protection against weather events rather than earthquakes.
THE LONG WALK HOME
Wellington City-based commuters are being invited to take part in Wellington's annual long-distance walking event, The Long Walk Home, on Friday.
The walk was organised to acknowledge that if a large earthquake struck Wellington on a weekday, many of the city's 80,000 daily commuters would probably be forced to walk home.
The 30-kilometre walk, organised by Rotary Clubs of the Hutt Valley and Wellington Region Emergency Management Office (Wremo), will take place between 1pm and 7pm. It will start at Westpac Stadium and end at County Lane in Silverstream.