READING (AP) — An MBTA employee from Reading has figured out a way to save the transit agency thousands of dollars annually in trolley engine repairs by using a simple hair cap and some electrical tape.

The Massachusetts Bay Transportation Authority, challenged by a high debt load and facing an unpopular fare increase, has to deal every winter with Orange Line train motors failing when air intakes get clogged with snow.

The engines are expensive to repair and even costlier to replace.

But Tom McHale of Reading, a repair foreman for the agency, was in a Boston wholesale butcher shop buying steak tips for a New England Patriots playoff game in late 2004, when he hit upon an idea.

The fine-mesh hair covering he was required to wear looked to be about the same size as the air intake on the Orange Line motors.

McHale, 42, took the hair cap home and a few days later taped it over an air intake. "It fit perfect," he said. Air was still able to pass through the mesh, but snow could not.

A major snowstorm can cripple motors on the Orange Line, T officials said.

Snow can be sucked up by a moving train and drawn into an air intake designed to cool the motors. As the train stops and starts, the snow melts and refreezes into thick squares that block the intake, causing the motors to overheat and fail.

Repairing a motor can cost $9,000. Replacing it costs between $35,000 and $50,000. Using the polypropylene hair caps, which cost $50 for a box of 1,000, will save the agency $126,000 in repairs in an average year.

Last winter, which was mild, the T did not experience any engine failures on the largely aboveground Orange Line, thanks in part to McHale's idea.

Before McHale came up with his idea, the T tried a number of different methods to block the snow. But nothing has worked as well as the hair cap, which is now part of the T's standard operating procedure.

Orange Line operating documents read that before a snowstorm, "All traction motor intake filter cage assemblies shall be wrapped with a protective hair net, taking care to fully cover any possible opening where the ingestion of snow is possible. The hair net shall then be secured using standard 1 1/2-inch electrical tape."

The mesh hair caps are removed when it gets warmer to allow the motors to cool properly.

McHale is scheduled to be promoted and honored for his idea on Thursday.

The solution does not work on Red Line cars because of difference in their configuration, T officials said.