KiwiRail is laying on extra trains to protect Auckland's pre-Christmas freight supply lines during a four-day closure of Auckland's container port, which began last night with a strike.
The Maritime Union intends holding two 24-hour strikes, until 10.30 tonight and on Monday, which will be exacerbated by a 48-hour lockout by Ports of Auckland of 327 workers in the intervening period.
That has already disrupted six ships, three of which have been diverted to Tauranga and another to Wellington.
A fifth will wait out the disruption in Auckland and another has yet to decide what to do.
The disruption comes at a busy time of year, and is expected to cost the Auckland Council-owned port company $1.2 million in direct losses, not counting the impact on importers and exporters.