Today's preliminary TAIC report into the engine failure on the Kaitaki ferry in January found KiwiRail had not followed the manufacturer's guidance in relation to the use of rubber expansion joints. Photo: RNZ / Angus Dreaver
Analysis - On Thursday KiwiRail's boss, called to account for Wellington's train chaos this week, told MPs that they had a "first-class" assurance and audit regime.
On Friday, Auckland commuters faced their own train disruption due to what KiwiRail said was a build-up for weeks of detritus on overhead lines.
Shortly after that, the public found out in a new transport investigation report that KiwiRail had put a 13-year-old rubber expansion joint into a ferry engine.
When the joint ruptured, it became a whole lot harder to restart the Kaitaki's engines as it drifted off rocks near Wellington in January for hours with 800 people on board.
The joint looks completely mangled in photos in the short, preliminary Transport Accident Investigation Commission (TAIC) report released on Friday.
The rubber expansion joint that failed on the Kaitaki ferry. Photo: Supplied
Complicating things for KiwiRail's "first-class" assurance and audit was what it did next.
TAIC said that after January's ferry power loss, KiwiRail put out new guidelines on the rubber joints.
These stated they could be stored for up to four years - not 13 years - and then used for up to four years.
That means a ferry could have a joint that is up to eight years old.
"This does not comply with the manufacturer's guidance and does not take into account the date of manufacture," the commission's report said.
The rubber expansion joints "begin to deteriorate from the date of manufacture".
In fact, the guidance was to store them for no more than eight months, and to replace them regardless within five years.
Is eight months the limit, or is KiwiRail's four years okay? The call comes down to the regulator Maritime NZ.
Friday's recommendation is that Maritime NZ satisfies itself the ferries are fit for purpose in light of the manufacturer's eight-month, five-year guidance.
Within half an hour of that recommendation coming out, KiwiRail put out a media release headed: "Interislander sorry for loss of power incident, outlines steps to assure safety."
The steps include replacing all of Kaitaki's rubber expansion joints.
But the media release also said: "Rubber expansion joints currently used in Interislander's safety-critical systems are from a manufacturer who advises a storage life of up to 10 years, and an in-service life of up to five years."
Later, KiwiRail told RNZ's Midday Report there were various standards for storage and use from various manufacturers - and it had settled on four years for both, as some sort of average.
It is claiming its regime for inspecting and replacing the joints "exceeds" the commission's recommendations.
That might be because it updated "Interislander's entire asset management regime" after the drift.
It was doing more "tracking" and "more frequent inspections of safety-critical equipment", KiwiRail boss Peter Reidy said.
First-class. Compliant. Safe.
KiwiRail made that defence about its audit regimes, around trains, at the select committee yesterday.
But, as with the ferries, these were audit regimes that have either had to be updated recently, or urgently require it: KiwiRail executives told MPs they made a core maintenance scheduling mistake on Wellington's trains - but did not know why and had to find out.
It was a "first-class" regime but there were gaps, they admitted.
The ferry investigators also found gaps:
"The commission is concerned that similar safety-critical components in the KiwiRail Interislander fleet may be at risk of failure if their dates of manufacture have not been accounted for in the replacement schedule," TAIC's report said.
In the gaps, a lot has been going wrong.