Shell workers knew days in advance that a company drillship which went aground in stormy conditions in Alaska could be facing disaster.
An official at the oil firm has told a US coastguard panel he had been planning for a crew evacuation four days before the Kulluk grounded off Kodiak Island.
Norman Custard, Shell’s Alaska emergency response leader, said it was clear towing failures could lead to an incident.
The Kulluk, having completed preliminary drilling on an exploration well in the Beaufort Sea, broke away from its tow lines then support vessels attempting to regain control of the drillship developed their own engine and mechanical problems on December 31 last year.
Mr Custard said he began planning for a crew evacuation on December 27. On the opening day of the coastguard hearing into the grounding, Mr Custard said: “My first and foremost concern was those 18 people on board.”
Crew members were eventually evacuated by a coastguard helicopter on December 29. Shell has spent at least £3billion since 2005 acquiring offshore Arctic leases and preparing to explore in remote basins believed to hold vast oil riches, but the company has yet to complete an exploration well in either the Beaufort Sea, off northern Alaska, or the Chukchi, off the north-western coast. Legal, environmental and marine woes have stalled its progress.