railways around Canterbury not badly damaged from quake

Fortunately damage to railways around Christchurch from the earthquake seems fairly limited.  Extracted from yahoo nz news:

"A coal train derailed in the Christchurch suburb of Heathcote with seven wagons affected, but remained up.
The train driver reported cracks in the Martindale Bridge, so the police could stop traffic.

KiwiRail chief executive Jim Quinn said track inspections had begun.
Damage to track include:
- Buckles in the Addington area
- Buckles between Belfast and Rangiora
- A slip on the city side of the Lyttelton Tunnel."