Between 2013 and 2016 , the DXC class were fitted with fire suppression to run the TranzAlpine through the Otira Tunnel on the Midland Line due to a change in requirements resulting from the Commission of Inquiry in the Pike River Mine disaster , and as well on any other passenger trains on the Main North and Main South lines . Because of this , the number of Otira bankers have gone from three to five , which allows any loco without the system to be shut down . In mid 2016 , the number of bankers were reduced from five to four . , all 32 units have been fitted with fire suppression
Pike River Mine disaster
Pike River Mine disaster
New Zealand DX class locomotive