When the Presses Replaced the Hands

The machines that built the secret.

In 1942, when Robert Wagner came to work at Harbison-Walker's Mount Union plant, hand molding accounted for 90 percent of production. The company had patented special impact presses made right here that transformed the work. These machines produced denser brick that could better withstand the extreme temperatures inside coke ovens. By the late 1970s, about 95 percent of the coke oven brick shapes leaving Mount Union were made by machine.

The presses were a competitive advantage worth protecting. When the plant closed in 1985, former customers needed replacement brick for coke ovens still in use. The plant's retired manager, with three of his former workers, shipped the molds to a plant in Utah where replacements could be made. The remaining presses were destroyed, and the company regarded the press design as a valuable industrial secret.

The photo shows the molding room bucket line feeding materials into the machines that built an industry.

If your grandfather or great grandfather worked at the brick plant, there's a chance he ran one of those presses or watched them transform the work.

Checked 2026-10-05 · Historic Mount Union collection

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