A mystery has persisted during the two-year saga of labour turmoil at the Port of Portland, which expects a decision by Hanjin Shipping any day now whether the port's biggest ocean cargo carrier will pull out.

Why would longshore workers stage slowdowns-which they deny, but which federal judges ruled they have conducted-and risk losing Hanjin, jeopardizing their own jobs?

An answer appears in Section 20 of the 241-page contract between the International Longshore and Warehouse Union and the Pacific Maritime Association, which represents West Coast cargo carriers, terminal operators and stevedores that employ dockworkers, reported Associated Press Newswires.

The contract provision, called the Pay Guarantee Plan, requires employers' group to establish a US$20 million annual fund to pay senior union members when they don't work.

The extraordinary practice of paying longshore workers who aren't working also may help explain why a longshore lockout by Portland-area grain terminals has lasted almost a year with no sign of resolution.

Portland longshore workers have received $547,000-more than a quarter of amounts paid for not working along the entire West Coast-since July 1, when the fiscal year began.

Payments to the idled Portland dockworkers are running at about $17,000 a week, according to the Maritime Association, which responded to questions this week concerning the practice after months of inquiries by The Oregonian.

Pat McCormick, a spokesman for the grain handlers, says that in general the long-standing payment plan "creates an opportunity for union members to be kept close to whole, and that results in less incentive for them to get the dispute resolved."

In the separate case of the port's container terminal, he says, the pay guarantee "lowers the threshold of pain for the longshoremen if those jobs did go away because of Hanjin."

Seoul-based Hanjin is expected to announce next week whether it will continue weekly transpacific calls on Portland, a service that supports 650 jobs including those of longshore workers.

Hanjin managers say the main reason they'd drop Portland is low longshore productivity, which hasn't significantly improved since December 12, when Governor John Kitzhaber announced a deal giving the union disputed work handling refrigerated containers.

Oregon exporters and importers anxiously await Hanjin's decision, because they would have to pay extra to transport each container back and forth to Seattle, Tacoma or other terminals if the shipping line departs.

Port of Portland commissioners, hoping to keep Hanjin, which handles 78 percent of the terminal's cargo, have approved subsidies of at least $20 a container to be paid to shipping lines.

Most unions use a portion of their members' dues to build up strike funds, to tide over workers in case of labour disputes. But the San Francisco-based longshore union negotiated the employer-financed pay guarantee plan, known as PGP, into its contract years ago.

"PGP is funded by employers of longshoremen coast-wide through an assessment on tonnage," said Wade Gates, a Pacific Maritime Association spokesman. The association, he said, "has not projected the impact on PGP if Hanjin leaves Portland".

If Hanjin pulled out, the longshore union overall wouldn't lose work, because all container handling at West Coast ports is conducted by its members. Some Portland longshore workers could be reassigned to other ports, or choose to move.

But remaining union members with seniority, so-called Class A and Class B longshore workers, could be eligible for guaranteed pay if work wasn't available at other Portland terminals. The pay can last indefinitely, the only cap being the West Coast maximum, currently $20 million a year, Gates said.

Portland has 361 Class A longshore workers and 78 Class B workers who could qualify for the guaranteed pay, Gates said. Another 219 so-called casual dockworkers aren't eligible, he said. He did not release numbers of Vancouver longshoremen, or amounts of PGP pay they've received while locked out by United Grain Co.

"After applying for state unemployment," Gates said, "Class A longshoremen are eligible for up to 38 hours of PGP per week at their individual basic pay rate, and Class B longshoremen up to 28 hours per week, up to $35.68/hour."

That pay, translating to about $70,000 a year for Class A longshore workers, isn't much compared to many senior union members' incomes, which range into the six figures including shift premiums and overtime.

Jennifer Sargent, a longshore union spokeswoman, said in an e-mail that "the Pay Guarantee Plan is a negotiated benefit designed to provide limited income to longshore workers when work is not offered to them and they are otherwise available to accept it."

"In the case of the Marubeni grain elevator in Portland," said Sargent, referring to Columbia Grain Inc, "the company has aggressively locked out the workforce and are not offering any work. Still, any displaced worker is required to accept other work throughout the port before being eligible for PGP."