American Railcar Industries says it plans to hire about 230 workers at its Arkansas plants in Paragould and Marmaduke over the next several months. The company plans to hire about 70 employees by the summer at Marmaduke, where tank cars are built. Another 160 people are to be added at Paragould, where a new 70-foot car is being built. Currently, about 270 people work at the Marmaduke plant and about 280 at the Paragould plant. American Railcar is based in St. Charles, Missouri.