LOUISVILLE, Ky. (WDRB) -- It is a Louisville-based operation you probably have never heard about, but it is now playing a significant role in the East End Bridge Project.

At the end of East Chestnut Street you find a green metal building. Inside some heavy industrial work is underway.

Wednesday was the first day that DSI Underground Systems began using its giant pressers to bend steel beams.

"What we are doing," explains DSI General Manager Bob ILiff, "is building the supports that will support the tunnel and eventually all of our material will be covered up and you won't be able to see it, it is one of the reasons we have a low profile, because our product is always hidden in a hole."

ILiff further explains how the beams work. "The beams will take the load of the earth that is pressing down and pressing on the tunnels so it will give stability to the tunnels and that will allow motorists to drive safely through them."

The German-owned DSI has been in Louisville for many years, but has stayed mostly under the radar even though it conducts business all over the globe.

If you have driven through just about any tunnel anywhere, chances are DSI's work is keeping that tunnel from caving in.

"We've done the Cochran Hill Tunnel (I-64 in Cherokee Park) years ago, the tunnel through the historic Cumberland Gap in Kentucky and the Big Dig in Boston, and the New York and Washington D.C. subway systems," says ILiff.

Mary Ellen Wiedorwohl from the city's economic arm toured the operation on Wednesday.

She was impressed. "Here we have the world leader in these underground metal supports for tunnels right here in Louisville," she says, "which has an historic base as an advanced manufacturing hub."

DSI has 40 employees in Louisville, most whom are trained on the job.

"The beam bending press is a learned thing," says ILiff, "it is not something you can learn outside this plant because nobody else does this kind of work."

The first of the steel beams is scheduled to be delivered to the tunnel site on Thursday.

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