The Arctic’s vast oil and gas treasure will remain buried for another year. Shell has announced it will postpone its controversial drilling program off the coast of Alaska until next year, after a device on its oil-spill containment vessel broke during testing.

In its quest to be the first company to drill offshore in the Arctic since the 1980s, Shell has already encountered lawsuits from environmental advocates, an accident in which its drill ship dragged its anchor shoreward, months of unrelenting sea ice that forced it to scale back its plans, a traditional whale hunt by native Alaskans during which drill ships can’t operate, numerous air quality problems with its oil-spill recovery vessel, and now the impending return of seasonal ice cover to the Chukchi and Beaufort Seas, where the company holds permits.

The final straw was the failure of equipment on Shell’s oil spill recovery barge, the Arctic Challenger, during testing of the vessel near Seattle this week. As the ship lowered an oil collection “dome” into the water, the dome cracked for reasons that are still unclear, according to Shell spokesperson Curtis Smith.

Environmental groups are feeling vindicated. In a statement, the Sierra Club said: Shell’s announcement is recognition of what we’ve been saying all along - the company cannot safely drill in our Arctic waters.

The US Bureau of Safety and Environmental Enforcement has said Shell cannot drill into oil-bearing rock until government inspectors approve its oil-spill recovery barge. So yesterday, the company decided that it would take too long to repair the dome and determine what went wrong with the barge, putting it past the 24 September deadline when it must stop drilling in the Chukchi.
In a statement issued yesterday, Shell said: We are disappointed that the dome has not yet met our stringent acceptance standards; but, as we have said all along, we will not conduct any operation until we are satisfied that we are fully prepared to do it safely.

The drill ship Noble Discoverer started on the first well in the Chukchi on 9 September. But the drill bit had barely made a dent before an iceberg moved into the area, endangering the ships and forcing Shell to halt operations after a single day.