A looming rail work stoppage in Canada is worrying U.S. businesses and threatening deliveries of cars, timber, petroleum products, grains and other crucial supplies. Already, scheduled shipments of perishable and hazardous products have been halted. …Canadian Pacific Kansas City advised that starting Tuesday, it would stop all shipments that start in Canada, as well as those originating in the US headed for Canada. The U.S. railway Union Pacific has said a shutdown would sideline more than 2,500 railcars from crossing the border each day. One of the largest U.S. rail unions, which is affiliated with the Teamsters, has told members that they can refuse to operate the two Canadian companies’ trains in the United States. The companies say they had planned to continue operations in the United States. …Edward A. Hall, president of the Brotherhood of Locomotive Engineers and Trainmen, instructed the union’s 51,000 members not to cross any “picket line they encounter”.