Investigation after Auckland rail failure

Passengers stranded at the Britomart station yesterday afternoon after a fault in Wellington shut down Auckland's entire rail network. Photo / Dean Purcell

An investigation has been launched into possible passenger safety breaches caused by a signal failure which hobbled Auckland's entire rail network.

All train services in Auckland were shut down when power went out at the KiwiRail National Train Control Centre in Wellington at 4pm yesterday.

The outage lasted for about an hour but caused disruption for much longer as commuters waited for backed up trains to start moving again.

The Transport Accident Investigation Commission today assigned two investigators to look into the network failure.

A spokesman said the signal outage had the potential to compromise safety.

KiwiRail admitted its power systems are not robust enough after a fault caused the total failure of Auckland's rail network during rush hour.

KiwiRail chief executive Jim Quinn this afternoon said the outage was caused by a faulty uninterruptable power supply (UPS) unit which feeds the Auckland network control desks.

"While we responded as quickly as possible to remedy the situation and had the network up and running again in just over an hour, the existing power system design simply wasn't robust enough and we are taking immediate steps to further minimise the chance of this type of incident happening again."

Mr Quinn said the faulty power unit was being replaced immediately.

He had ordered an independent review of the power system design at the National Train Control Centre.

The centre had never experienced a similar outage before, he said.

"We again apologise to all the commuters who were affected by this."

Auckland Mayor Len Brown earlier said the network failure was disappointing at a time when hundreds of millions of dollars were being spent on upgrading Auckland's rail network.

"We've a got fully integrated electric rail system coming into position mid next year, and we do not want any of these types of control issues impacting on the delivery of super modern service."