Kiwirail staff yesterday declared confidence in their emergency procedures should a train break down in the Rimutaka tunnel.
In the wake of Monday's train breakdown near Featherston, one passenger raised concerns at the lack of an evacuation plan should the train fail in the tunnel.
Johnny Johnson, from Carterton, said he'd been concerned for some time about the safety of the trains when underground. The Rimutaka tunnel, at 8.8km, is New Zealand's second longest.
The Pike River disaster last year had prompted Mr Johnson to look into the issue, and yesterday's hold-up strengthened his concerns.
"If the train breaks down, what happens?" Mr Johnson asked. "If it happens, we've been so ill-prepared for so many things.
"After this business yesterday concerning an engine that wouldn't push the train uphill into the tunnel, I don't know ... we seem to be going backwards."
Among Mr Johnson's concerns were access for firefighting equipment, response time, ventilation, and a lack of instructions for passengers about what to do in the event of an emergency.
Greater Wellington regional councillor Gary McPhee said he'd been reassured by Kiwirail staff that three-yearly drills were held with emergency services.
The most recent drill was in 2008.
Angus Gabara, regional council rail projects manager, said there were no on-board instructions for passengers because staff were trained to manage the situation.
The Kiwirail spokesperson said the Rimutaka tunnel was designed so that "there is always the opportunity for a disabled train to leave the tunnel by simple gravity".
The spokesperson said the tunnel had "good natural ventilation", and carriage materials were flame resistant to an international standard.
If necessary rail capable vehicles could be used both to evacuate passengers and transport firefighters.