One of the challenges when upgrading coal-conveying equipment at Superior Midwest Energy Terminal, a high-volume coal transshipment terminal at the western edge of Lake Superior, was its ambitious loading schedule. Downtime at the facility is limited, which doesn’t afford much opportunity for maintenance and equipment changes. System upgrades are usually handled during the annual January and February maintenance outages. Martin Engineering of Neponset, Illinois undertook the project at the terminal. The company custom-engineered coal transfer chutes specifically to address the flow rate and physical characteristics of the terminal’s coal, to help avoid blockage and minimize fugitive material, reducing costly interruptions to clear plugged sections and clean up spills.
Uptime is key
Director of Terminal Operations Marshall Elder explained: “We load ships around the clock, so it’s difficult to find time to make changes to our system. We cannot keep vessels – and our customers – waiting for coal while we make changes to our equipment,” he said. The entire transfer chute system was designed and constructed off-site by Martin Engineering, then installed in just four weeks of scheduled downtime.
Superior Midwest Energy Terminal handles approximately 22 million tons of western coal annually. The terminal unloads the unit trains bringing coal from mines in the Powder River Basin and transfers it onto vessels for transport to utility power plants in the U.S. and Canada. Located on a 200-acre site at the mouth of the St. Louis River, the 30-year-old facility has become one of the largest coal handling terminals in the world.
To receive its coal, the terminal unloads more than 1,400 trains from the Burlington Northern and Santa Fe (BNSF) and Union Pacific railway lines each year. “We unload railcars at 5,000 tons per hour, roughly 45 cars an hour, or a full 123-car train in about three hours,” Elder observed. The terminal then loads that coal onto approximately 450 vessels during a 305-day shipping season. Shiploading operations run from late March until mid-January, when ice closes the Wisconsin port.
According to Fred Shusterich, President of Midwest Energy Resources Company (MERC), a DTE Energy Company that owns and operates the terminal, “This is the largest-capacity coal terminal having only one si ngle-car railcar dumper. We put more coal through that single-car dumper than any operation in the world,” he said.
“MERC is a high volume operation,” Shusterich emphasized. “And because of that fact, we make the investments to maintain peak performance levels of our primary coal-handling operations.”
Benefits of custom-engineered chutes
Engineered specifically for the Superior terminal, the Martin® Inertial Flow™ Transfer Chutes have minimized previous problems with plugging. “When a chute used to plug up, the material would spill onto the floor and around the conveyor idlers,” Elder explained. “And at 11,500 tons per hour, it doesn’t take long to put a large volume of material outside the chute. That’s a lot of spilled coal, and a lot of man-hours to clean it up. Minimizing the plugging problem has been a very positive aspect of these engineered chutes.”
