Crew slides steel bridge over gap in Glacier road

GREAT FALLS – Workers slowly slid a massive metal bridge over a gaping hole in Glacier National Park’s Going-to-the-Sun Road on Wednesday.

“We’re on track to open this road on Sunday,” said John Schnaderbeck, project engineer for the Federal Highway Administration.

Last November, a powerful storm nicknamed the Pineapple Express dumped more than 9 inches of rain on Glacier Park in three days, washing out the 75-year-old, 50-mile alpine road in three places.

Two of those washouts already have been filled in, and a crew from Neil Structural Repair of Noxon was bridging the third under brilliant blue skies Wednesday.

The Mabey bridge, designed for the military to replace bombed-out bridges in battle zones, rests on heavy-duty steel beams, each 32 feet long and 2 feet high.

Steel guardrails rise 5 feet high on each side of the 22-foot roadway, which will be covered with 120 steel plates, each about 6 inches thick and weighing several hundred pounds.

On Wednesday, crews had the bridge assembled, except for the plating, and were gingerly sliding it on steel rollers over the 108-foot chasm.

Schnaderbeck said he expected to have the bridge secure by day’s end Wednesday.

Park officials had originally planned to put the bridge on top of the existing roadway and anchor it to the mountain, but changed their minds and created below-surface concrete pads for the ends to sit on.

The bridge is strong enough to handle a full load of Glacier Park traffic, including tour buses, Schnaderbeck said.

Even as traffic flows over the bridge this summer, crews will be working beneath it.