Dockworkers at 29 West Coast ports were locked out by the Pacific Maritime Association, representing shipping lines and terminals, when the association accused them of deliberately staging a work slowdown after contract negotiations stalled amid disagreements over pensions, benefits and whether jobs created by new technology would be unionized.

Officials for the 10,500-member International Longshore and Warehouse Union said their members were paying particular attention to safety rules following five work-related fatalities since May. One worker was run over by a huge forklift and killed. It's like working in the middle of a freeway, said an ILWU spokesman.

The ten-day lockout cost the economy up to $2 billion per day by some estimates. U.S. District Judge William Alsup in San Francisco ordered it ended, and union and government lawyers agreed to an 80-day cooling off period.

Dockworkers vowed to adhere closely to safety rules as West Coast ports reopened, raising the prospect of further conflicts with management. In some cases, employers said cargo wasn't being moved quickly enough.

Longshore workers say they are pressured to bypass safety rules to meet production expectations. Their contract sets a 10 mph speed limit in dockyards, but workers routinely drive more than 30 mph, according to reports.

Also, workers should wear a harness and tie onto a fixed object when standing atop cargo containers. But to save a couple of minutes, workers jump onto containers without tying off.

Union members promised to work as hard as they can without sacrificing safety.

It could take an estimated six to seven weeks to clear the backlog of cargo. About 200 ships were lined up outside ports, waiting to pick up or unload containers held up by the dispute. These congested conditions might threaten the safety of workers, and the union hinted at further slowdowns.

The relatively high pay of dockworkers has made it difficult for unions to generate worker solidarity. Dockworkers earn about $106,000 on average. The highest paid workers, such as foremen, earn an average of more than $166,508 for full-time work.