The costs of BHP’s runaway train derailment in the Pilbara continued to grow yesterday, with the mining giant revealing iron ore stockpiles at Port Hedland would not be enough to cover the full period of interruption from the incident.

BHP’s crucial transport link between its mines and the port was severed on Monday morning after it was forced to derail a fully-laden iron ore train about 120km south of Port Hedland.

The train, comprising four locomotives and 268 cars, had careered for 50 minutes at an average speed of 110km/h over 90km with no one at the controls after the driver got out to check a carriage and the train continued on its journey.

More than 130 workers with a fleet of heavy equipment are scrambling to clear wreckage from the crash site and fix 1.5km of damaged track.

BHP said it expected to have partial rail operations back up within a week and would liaise with customers in relation to its contractual commitments concerning missed deliveries.

Industry sources said it was unlikely the company could declare “force majeure”, which might protect it from incurring penalties for failing to deliver product.

BHP may also be on the hook for demurrage as iron ore carriers begin stacking up off Port Hedland.

Demurrage is a charge payable to the owner of a chartered ship on failure to load or discharge the vessel within an agreed time.

About 29 vessels were off the coast of Port Hedland yesterday, which could rise to almost 50 in the next week unless BHP can cancel charters.

An industry source, who previously worked as a senior executive connected to the Pilbara iron ore sector, estimated BHP would lose about 800,000 tonnes of ore worth about $80 million in revenue each day it was unable to ship from Port Hedland.

He predicted BHP would run out of port stockpiles by Friday.

“I reckon the earliest they could have a track back up is Tuesday morning, and that would be 5.5 million tonnes in lost production,” he said.

“That is my minimum assessment of the total impact over the next two to three weeks until things return to normal, (but) it could be much higher.”

The source said BHP would also need to replenish port stockpiles to about 20 per cent before it could resume shipping at normal rates.

The company has not yet revealed what effect, if any, the incident could have on its full-year production estimate of 273-283 million tonnes.

However, it is expected to struggle to make up for lost production with its system already operating near full capacity and with cyclone season approaching early in the new year.

Image: BHP Train Derailment Wreck, Synarah Murphy North West Telegraph.