Nebraska City Station thaw shed

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WHAT IS IT? A shed used only in winter to thaw the coal in train cars prior to emptying them for use at Nebraska City Station (NCS). As the coal travels from Wyoming, condensation from the moisture in the coal (about 30 percent) – and sometimes rain and snow – can cause the coal to stick together.

Coal moves down the first of several conveyor belts on its way into the power plant. In the background, a machine scoops the coal down onto the belt from where it was released from the train cars.
Coal moves down the first of several conveyor belts on its way into the power plant. In the background, a machine scoops the coal down onto the belt from where it was released from the train cars.

FUN FACT: Just like when you bake a cake, a spray is used to line the train car to aid in the coal’s removal once it gets to the plant.

HOW DOES IT WORK? The first stop once it gets to the plant, the train cars move into the shed until they are situated over the heaters in the floor. The cars are thawed one of two ways, depending on the weather. During frigid temperatures, the cars are moved in seven at a time and stopped completely over the heaters. There they will sit for 15 to 30 minutes to thaw completely. Eric Bender, supervisor of material handling at NCS, said it can take up to 16 hours to thaw a train with 150 cars if it’s really cold outside.

The second thawing method slows the train to about ½ mph and moves it slowly over the heaters. This method is used when winter temperatures are a bit warmer. The average time it takes to empty a train is between six and eight hours. When a train is thawed using the second method, it can take between 2 and 2 ½ hours.

Eric Becker, supervisor of material handling at Nebraska City Station, tests the air temperature inside the thaw shed at the plant. When the heaters are on, the air can be as hot as 150 degrees.
Eric Bender, supervisor of material handling at Nebraska City Station, tests the air temperature inside the thaw shed at the plant.

HEAT INDEX: When at full-power, the heaters can register at more than 500 degrees. The air temperature inside the thaw shed can be as high as 150 degrees when the heaters are on. At that temperature, crews have to be mindful of surfaces that can burn their skin at such a high heat.

The temperatures are a delicate balance. If the coal is heated for too long, it could catch fire due to its combustible nature.

Bill Creek, yard equipment operator first class, demonstrates the switches that open train cars to deliver coal at Nebraska City Station.
Bill Creek, yard equipment operator first class, demonstrates the switches that open train cars to deliver coal at Nebraska City Station.

SHED CREWS: Three-person crews are used to operate the thaw shed and dump the coal. A crew leader is stationed in the office to oversee the operation. Another member is inside the shed spotting the cars and ensuring they are over the heaters. A third crew member is stationed in the operations tower, operating switches that open the cars to be emptied beyond the shed.

 

Laura King-Homan

About Laura King-Homan

Laura King-Homan is editor of The Wire and a communications specialist at the Omaha Public Power District. She has nearly 20 years of print journalism and design experience, most of that time spent at the Omaha World-Herald.

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