Original Date: 08/26/1996
Revision Date: 01/18/2007

A fleet of 22 refractory-lined, steel rail cars called torpedo bottles are used by Weirton Steel Corporation (WSC) to transport molten metal from the blast furnace operation to the BOP facility. Torpedo bottles have a 225-ton capacity and can maintain the metal in a molten state for pouring into the BOP vessel for up to 22 hours. The refractory linings in the torpedo bottles are periodically replaced, causing critical transport capacity to be removed from the process flow. The frequency of the replacement process is constantly reviewed and improved.

In the past, torpedo bottles were relined after carrying 350,000 to 400,000 tons. In 1996, the number had grown to 500,000 tons and was still expanding. This increase has been achieved through various means. The refractory bricks are coated with a special gunning material to protect them. Inspections are conducted to monitor the shell temperature; visually inspect the linings; track the tons carried since the previous relining and gunning; and drill test holes. Thermographic readings are recorded each week. When data indicates the barrier is failing in a particular area, test holes are bored into the brick to determine the remaining thickness. These readings allow partial regunning in specific areas that extends the life of the bricks. These practices are expected extended the lining usage to more than 600,000 tons.

For more information see the Point of Contact for this survey.