Amtrak announced in October 1976 that the "North Coast Hiawatha" would be the second train, after the "Empire Builder", to receive the new bi-level Superliner coaches, then on order from Pullman Standard. In the end the train was cancelled before the Superliners entered long-distance service. In the spring of 1977 Amtrak added seven hours to the schedule, increasing it to 52 hours 30 minutes. The change was prompted by new speed restrictions on Amtrak trains after a rash of derailments involving the new EMD SDP40F diesel locomotives. In September Amtrak eliminated the off-day Chicago—St. Paul service, leaving the "North Coast Hiawatha" with three trips a week. Amtrak reduced the "Empire Builder" to quad-weekly service as well. The "Twin Cities Hiawatha" returned as a daytime service between Chicago and Minneapolis.