Rail congestion has slowed deliveries. Minneapolis Star Tribune/Zuma Press Saying they are running short on coal, electric utilities from Minnesota to Texas are trying to pressure Warren Buffett ’s BNSF Railway Co. to speed up deliveries on its congested tracks before the worst of the winter weather hits. One group of utilities has petitioned federal regulators to impose a timetable on BNSF to add workers and improve tracks leading east from coal fields in Wyoming. Utilities also are negotiating directly with BNSF. In Minnesota, politicians and regulators warn that consumers could pay millions of dollars in extra charges if utilities have to buy high-cost backup power because they can’t operate their coal-fired power plants. BNSF, which is owned by Berkshire […]