KiwiRail has conceded that nearly 10% of the new Chinese-made flat top wagons are already out of commission, with 44 of the 500 wagons undergoing repairs or maintenance.
The state-owned enterprise was criticised last year, after its decision to award the $49 million contract to the China CNR Corporation, rather than have them built at its workshops in Dunedin and Lower Hutt, contributed to 44 workers being made redundant at the Hillside workshop.
Most of the wagons were out of commission because of a "wheel slip issue", KiwiRail chief executive Jim Quinn said.
He said KiwiRail planned for around 5% of the wagon fleet to be undergoing maintenance or repair and that the situation was "not that far from normal".
"If you remove those wagons, we just have a standard number of what we would expect to be under maintenance at any one time. Two-thirds of the ones that we have built in New Zealand have exactly the same issue," Mr Quinn said.
However, Dunedin South MP Clare Curran said the news was "no surprise".
"There are question marks around the quality of the steel and the build and that's just a fact," she said yesterday.
"I'm very sceptical of the figures that KiwiRail have been providing. I think they have had a deliberate strategy to build them overseas and I'd like to see some independent figures and an independent evaluation of the process."
KiwiRail had estimated it would cost around 25% more to build the wagons in New Zealand, but both the figure and process were dismissed by the Rail and Maritime Transport Union yesterday.
"KiwiRail will inevitably have whole-of-life cost blowouts if it continues to take a short-term procurement approach solely focused on the cheapest products available," RMTU general secretary Wayne Butson said.
"Value is not just money, nor is it just the purchase price. It is also about ongoing repairs and maintenance work, as KiwiRail are finding out, not to mention the primary and secondary jobs that are created and industries supported when goods are manufactured locally."
Mr Butson said construction of the 500 wagons would have been "an easily achievable target" for the Dunedin and Lower Hutt workshops.
"Instead the company sent the work overseas and 44 workers in Dunedin lost their jobs."
