Trains roll down one of Canada's two major freight rail lines.

TORONTO (AFP) – A union threatened to strike on one of Canada’s two major freight rail lines on Friday, just hours after the company resumed running after a potential disruption. Destructive stop. Trains are expected to continue running until at least Monday morning.

Canadian National and Canadian Pacific Kansas City Ltd. locked out their workers on Thursday when negotiations for a new labor contract broke down. That led to a near-total shutdown of the country’s freight rail lines for more than a day, until Air Canada resumed service. CPKC-operated trains remained grounded and its workers, who had already been on strike since Thursday, remained on the picket line on Friday.

The government has forced the companies and the union, the Teamsters Canada Rail Conference, into arbitration — an order the union is challenging. The union filed a 72-hour strike notice against CN on Friday morning shortly after announcing it planned to challenge the arbitration order, union spokesman Marc-André Gauthier said.

It was not clear whether the latest action would lead to CN trains being grounded again when the strike notice expires at 10 a.m. Monday. The entire matter could be decided before then by the Canadian Industrial Relations Board, which is overseeing the arbitration. In that case, CN employees could continue to work and CPKC workers could return to work while the union continues to challenge the arbitration order in court. All parties met with the CIRB that began Friday morning and continued into the afternoon.

“We do not believe that any of the issues we have discussed over the past few days are insurmountable, and we remain ready to discuss a resolution to this matter without further disruption to work,” the union said in its letter to CN management.

Canadian National, which has about 6,500 workers involved in the dispute, said the impact of the strike notice would depend on the timing of the CIRB’s decision. “It is in Canada’s national interest for the CIRB to rule quickly, before further damage occurs,” the railway said in a written statement. CPKC has about 3,000 engineers, conductors and dispatchers.

“The union’s latest actions will prolong the damage to our economy and put at risk the well-being and livelihoods of Canadians, including union and non-union workers in many industries,” said Perrin Beatty, president and CEO of the Canadian Chamber of Commerce.

Labor Secretary Stephen McKinnon announced the decision to force the parties into binding arbitration Thursday afternoon, more than 16 hours after the shutdown that shut down rail lines, saying the economic risks were too great to allow them to continue. He had rejected the arbitration request a week ago, saying he hoped negotiations between the companies and the union on a new contract would succeed. A spokesman for McKinnon declined to comment Friday.

“It’s not about disobeying the minister’s order. It’s about exercising our right,” Teamsters Canada President Francois Laporte said Friday as he announced the strike. “We will exercise our right within the legal framework.”

Canadian National trains began running at 7 a.m. across Canada, said CN spokesman Jonathan Abecassis. The development initially appeared to have at least partially ended a work stoppage that had threatened to wreak havoc On the economies of Canada and the United States. Both countries, in all industries, depend on railways to deliver raw materials and finished products.

“While CN is focused on its recovery plan and supporting the economy, truckers are focused on getting back on the picket line and holding the North American economy hostage to their demands,” Abecassis said following the union’s strike notice.

Getting one rail line back up and running is a relief for companies. In most previous rail labour disputes, only one Canadian rail line was shut down and the economy was able to weather the disruption.

Negotiations that began last year have been hinging on issues related to how workers are scheduled and contract rules designed to prevent fatigue. The railroad has proposed switching from the current system, which pays workers based on the number of miles they travel, to one based on their hours worked. The railroad has said the switch would make it easier to provide predictable schedules. But the union has resisted, fearing the proposed changes would erode hard-fought protections against fatigue and jeopardize safety.

similar Quality of life concerns Tough schedules and lack of paid sick time pushed U.S. railroads into bankruptcy strike edge Two years ago, before Congress and President Joe Biden stepped in and forced workers to accept the deal.

In Canada, another CN issue is the railway’s intention to expand a system that allows it to temporarily transfer workers to other parts of its network when there is a staff shortage in a particular area.

As for wages, the railways said they offered increases in line with other recent deals in the industry for what are already considered well-paying jobs. Canadian National said its engineers earn about $150,000, and ticket drivers earn about $121,000 for working 160 days a year, though some of their vacations are spent stuck in hotels en route between train journeys while they get much-needed rest. CPKC says its salaries are comparable.

Almost all of Canada’s freight by rail — worth more than C$1 billion ($730 million) a day and adding up to more than 375 million tonnes of freight last year — was halted Thursday along with rail shipments crossing the U.S. border. A number of small, short-haul freight rail lines that handle domestic deliveries continued to operate but were unable to deliver to any of the major rail lines while they were out of service.

About 30,000 passengers in Canada were also affected because their trains use CPKC lines. CPKC and CN trains continued to operate in the United States and Mexico during the shutdown.

Billions of dollars worth of goods move between Canada and the United States by rail every month, according to the U.S. Department of Transportation.

“There are a lot of goods and services that are shipped across the border,” Sean O’Brien, president of the International Brotherhood of Teamsters, said at a rally in Calgary, Alberta, on Friday. “If this company chooses to continue its bad behavior, it will have an impact. … They have a lot of decisions to make. And they have to make the most important decision: Reward these workers with what they’ve earned, and don’t try to compromise safety until they need to feed their bottom line.”