Executive summary
On Monday, 16 July 2001, at about 0825 the passenger doors on the left side of Train 8203 electric multiple unit passenger service, opened uncommanded as the train travelled through Tunnel No 2 between Takapu Road and Wellington on the North Island Main Trunk. The locomotive engineer immediately stopped the train in the tunnel.
The doors opened due to an electrical short circuit that was caused by heat from an overworked resistor bank melting the insulation on the door control wires. The crew manually closed the doors and the train continued to Wellington.
There were no injuries to passengers or staff
The safety issues identified included:
• the routing of an electrical cable conduit over a potential source of heat without suitable protection
• the non-compliance with a standard procedure for preventing an overload of resistor banks
• the unreliable radio communication between electric multiple unit passenger trains and train control while in Tunnels 1 and 2.
In view of safety actions taken by the operator to address these issues, no safety recommendations are included in this report.