KiwiRail probes injector failures

KiwiRail trains have seen an unexpected amount of failure in their fuelling mechanism, which is costing the company at least a million dollars.

In response to an Official Information Act request, KiwiRail said there had been a ‘‘spike in injector failures in late 2017 and again in May this year’’.

The company had ‘‘unplanned work’’ on 483 fuel injectors last year, compared to its unplanned work on three fuel injectors in 2016.

KiwiRail said the spike coincided with the outage of the Marsden to Wiri fuel pipeline, following its rupture.

The leak caused massive business disruption and fuel shortages, causing dozens of flights to and from Auckland Airport to be cancelled.

Warnings about the vulnerability posed by the pipeline date back to at least 2005, with independent reports highlighting the risk of a lack of aviation fuel in particular.

Back in 2012, Z Energy issued the former National government a blunt warning that the industry was failing to invest in infrastructure, and urging officials to take steps to improve it.

A contractor to the company, who did not want to be named, blamed the company’s use of cheap, high water-content fuel.

He said that most Euro five and six engines operated best on fuel that consisted of fuel with 50 to 60 parts-per-million (ppm) of water.

However, the company’s contract with Mobil allows for fuel up to 200ppm water.

KiwiRail said: ‘‘We do not consider that the injectors are or were defective but the matter is still under investigation with the assistance of our fuel supplier.

‘‘All up, the spend on replacement injectors, both planned and unplanned, is around 1 per cent of the annual rolling stock maintenance budget.’’

There is one engine failure being investigated, as is the cause or causes of the spike in injector failures. The estimated lifespan of an engine is between 34,000 and 36,000 hours.

The cause of the injector failures was ‘‘under review’’.

KiwiRail renewed its contract with Mobil for the supply of diesel fuel until October 2022, at an estimated annual spend of $34m.