CANTON – Like the jaws of a tyrannosaurus rex, a giant pair of shears bit into one steel beam after another that had held the Gilbertville Bridge together for 70 years.

The huge clippers attached to an excavator roared like the prehistoric monster as they chewed their way through one span, then began on the next.

Clang, creak, clunk.

By the end of last week, the first 200 tons of steel that had once been one of the bridge’s two spans was reduced to a scrap heap.

This week, the monster shears were working on the second span. A second pile of scrap metal should be completed by early next week.

Nearly 400 tons of steel went into the bridge in 1934 when it was built by PGH-Des Moines Steel Co. of Pittsburgh, which built many of the remaining steel-trussed bridges dotting western Maine. It is being taken down by Reed and Reed of Woolwich, which will recycle most of the steel, and use some of the girders to build temporary bridges on other projects.

Robert Stevens, a lifelong resident of Canton, watched as the bridge was built 70 years ago. Now, he’s watching it come down.

He wasn’t too happy about plans to remove the bridge at first, but now he says he’s used to it.

Stevens is also a member of the Canton Historical Society. He said the group is working to get at least one of the two steel plaques that had been attached to either end of the bridge. The plaques showed the date the bridge was built and the name of the contractors.

The new $4.4 million bridge is wider and longer than the old one, with a sidewalk that can accommodate both pedestrians and snow machines.

The project should be completed by the end of September, said Maine Department of Transportation engineer Catherine Mettey.