Freight trains in east Waikato were delayed about four hours yesterday and phone lines to the Waikato University, Waikato Hospital and Department for Courts were affected after a suspicious fire in a rail tunnel under Hamilton city.
Four fire crews were sent to the tunnel about 12.50pm yesterday after smoke
was seen coming from one of its entrances, Hamilton's chief fire officer Roy Breeze said.
The firefighters were reluctant to go into the seat of the fire because a high-voltage power cable was shorting out and insulation was burning, he said.
Once the cable's source was found and power cut, the crews were able to move in and get the fire under control, but not before several trains on the Hamilton-Tauranga line were stopped along the line.
The fire had affected electronic signals on the line and the trains were held until the signals were reset.
The 800m tunnel goes underneath central Hamilton and there is a closed and unused underground station in the area.
Mr Breeze said the old station had been set on fire recently and materials found at the seat of yesterday's fire indicated the cause was suspicious.
Toll Holdings spokeswoman Sue Foley said the North Island main trunk railway line was not affected and services on that line were running on schedule.
However, several freight and coal trains were held up on the east Waikato line.
Toll Rail driver Dave Jurgeleit was driving towards the tunnel in a train loaded with coal when he noticed smoke billowing out of it.
"I thought 'I don't think I'll go in there', it's all coal so I wouldn't have liked to stop in there," he said.
Mr Breeze said the tunnel went under several commercial buildings and because there was smoke seepage, occupants were warned but no building evacuation was necessary.
The fire also affected phone lines to the university, hospital and courts offices.
Two TelstraClear fibre optic cables which run through the tunnel were affected.
Telstra spokesman Mathew Bolland said the fire affected voice and data circuits which meant those affected could not make calls or send data such as emails. Services were expected to be restored by this morning.
Contractors were working last night to splice around the affected parts of the cables, bypassing the damaged sections.
