More than 3,000 Canadian National Railway Co. train operators went on strike just past midnight on Tuesday morning, shutting down Canada’s largest rail network.

The workers, represented by Teamsters Canada Rail Conference, and CN failed to reach an agreement on a new contract after several months of mediated talks, the union said.

“We’re on strike,” said Christopher Monette, a spokesman for the Teamsters.

Talks to replace an agreement that expired in July are scheduled to continue today at a downtown Montreal hotel.

“They talked right up until midnight and continued talking well past midnight,” Mr. Monette said by phone. “We’re still in negotiations. We broke to get some rest but it’s going to resume a little later today.”

CN has been winding down operations ahead of the possible strike, a safety measure taken to avoid leaving loaded trains in storage or on tracks. The railway stopped picking up some hazardous goods and interchange cars from other railways in the past couple of days, according to an internal memo seen by the Globe and Mail.

CN said in the memo it will use qualified managers to move operate some trains, focusing on container shipments.

However, the grain companies, farmers, chemical makers, miners and retailers that rely on CN to get their goods to and from market have no real shipping alternatives. Many are captive to CN, given their location, and trucks are too small.

The two sides failed to reach an agreement despite the urging of two federal ministers on Monday night. Transport Minister Marc Garneau and Labour Minister Patty Hajdu met with CN and union representatives separately in Montreal to try to settle their differences.

The union says the main issues are on drug benefits, time off and remote control train operations. Wages are not in dispute.

CN did not immediately respond to a request for comment.

CN and the same group of CN employees reached an agreement in 2015 after then-labour minister Kellie Leitch warned she would block any strike with legislation.

The strike comes at a difficult time for Jean-Jacques Ruest, CN’s chief executive officer. CN is laying off about 1,600 management and union staff as it faces declining freight volumes amid global trade tensions that have dampened exports. The world’s economies are also showing signs of slowing. Mr. Ruest was named CEO in July 2018, after serving as interim CEO for a few months. He took the lead at CN at a time it was facing complaints from shippers and the government about poor service, and oversaw a period of increased capital spending and hiring.

CN, which employs about 24,000 people in Canada and the United States, made a profit of $1.2-billion in the latest quarter and posted a 4-per-cent rise in revenue to $3.8-billion, compared to the third quarter of 2018. CN reduced its profit outlook due to the weakening economy.

Via Rail, Canada’s passenger train service that operates mainly on CN lines, will not be adversely affected by the strike, the union has said. Similarly, commuter rail operations in Vancouver, Toronto and Montreal will be unaffected.

This is the first strike at CN since 2009, when train engineers walked off the job for three days before settling. The Progressive Conservative government was preparing back-to-work legislation to avoid harming the economy.

Canadian pacific Railway Ltd. has had had three strikes by train crews since 2012. The 2018 walkout last less than a day, and the brief strikes of 2015 and 2012 were ended by legislation or amid the threat of legislation.

Today’s Liberal government has shown no interest in legislating ends to strikes. “The government of Canada supports and has faith in the collective bargaining process,” Ms. Hajdu said in a statement on the weekend. ​

The Globe and Mail, November 19, 2019