Storm exposes problem in bridge’s backup system

HANCOCK/HOUGHTON – The powerful storm which passed through the western Upper Peninsula early Thursday disrupted operation of the Portage Lake Lift Bridge Thursday and Friday, but a solution seems to have been found, according to Dan Weingarten.

Weingarten, Michigan Department of Transportation communications representative at the Ishepeming Transportation Service Center, said after the power outage caused by the storm, auxiliary power for the bridge was turned on, and then there was a problem with moving the deck.

“Something malfunctioned at that point,” he said. “They had trouble moving it under auxiliary power.”

The bridge was running normally after about 30 minutes, Weingarten said.

At about 9 a.m. Friday as the National Park Service’s Ranger III was leaving from Houghton to Isle Royale National Park, Weingarten said the bridge became stuck again in about the same position, again for about 30 minutes.

“The bridge crew attempted to lift the bridge with the auxiliary system,” he said. “They wanted to identify the issue that came up (Thursday).”

Both Thursday and Friday, the deck wouldn’t lower completely. There was a gap of about nine inches between the lower deck of the lift section and the road, and Weingarten said the bridge crew determined a malfunction of a sensor caused the problem both times. The sensor is supposed to let the bridge operator know where the decks are in relation to the road.

A tentative solution was found for the problem, which Weingarten said will work even if the power is lost again.

“There’ll be a permanent fix in place next week,” he said.

The apparently defective sensor, which caused the problem with the lowering of the bridge deck was part of the upgrades during the 18-month long maintenance of the bridge, which finished in April, Weingarten said.