Container ships are still unable to berth at the Port of Lyttelton because of quake damage and it could be Friday before a backlog of vessels can begin to be cleared.
The port was extensively damaged in the September and February quakes, and was particularly hard hit by the latest shakes on Monday.
Chief executive Peter Davie says the quakes further damaged the coal-loading facility and container terminal.
But he says rail operations in and out of the port are running as usual and the oil berth should be operating by the time the next tanker arrives on Monday.
