 NSB stated that they would demand a discount from Adtranz . Following the incident , the trains would have to be in for maintenance examinations every 100 @,@ 000 kilometers ( 62 @,@ 000 mi ) , rather than every 1 @,@ 200 @,@ 000 kilometers ( 750 @,@ 000 mi ) . With each exam costing NOK 50 @,@ 000 , NSB stated that this represented an extra cost of NOK 20 million per year . The contract between Adtranz and NSB states how often trains are to be maintained , and Adtranz holds a financial responsibility if the trains systematically need more maintenance than that . By 24 June , cracks had been found in two additional units . Similar cracks had occurred in the X2 trains , but after many years of operations . The same manufacturer had been used for the axles on both trains . In Sweden impurities in the steel , combined with undersized axles , were thought to be a cause , but replacements had caused the same issues . On 26 June , NSB stated that in April they had discovered that not checking the whole axle was a weakness in the maintenance procedures , but that despite this , no new examinations had been done . The reason this was ignored , was that there was nothing that indicated that this part of the axle represented a weak point . 
