Construction of the St. Croix River bridge remains on track despite recent difficulties finding equipment small enough to fit on an on-ramp, a Minnesota Department of Transportation spokeswoman said Friday.

Discussions with the general contractor, Lunda/Ames Joint Venture, centered on finding a smaller jack to stretch tension cables at one of the on-land piers that will support the eastbound ramp, said Kristin Calliguri.

"This back and forth is not unique to this section or to the bridge," she said. "That process happens at bridges all across the state."

The work stoppage on a small portion of the ramp from Hwy. 95 onto the bridge won't delay the bridge opening — set for the fall of 2017 — and isn't considered serious enough to require tearing down any ­portion of the ramp and starting over, Calliguri said.

Neither Michael Beer, the MnDOT bridge project manager, nor Lunda Vice President Brent Wilber were available to comment Friday.

Calliguri said Lunda/Ames had proposed using a jack that was too big to fit the space available and is working on a solution that MnDOT will review. No deadline has been set for that solution, she said.

"It isn't a serious problem" and doesn't affect construction of spans over the water, she said.

Three engineering letters exchanged with Lunda/Ames show MnDOT engineer Paul Kivisto first raised concern over the jack problem on May 24. The jack stretches cables, inside the bridge segments, that hold them tightly together to form the driving surface.

In January, MnDOT and the Wisconsin Department of Transportation announced the 2017 opening, a full year after originally planned because of equipment problems, material shortages and weather delays. However, the bridge span is now 80 percent complete.

The project's final cost is estimated to be between $617 million and $646 million, according to MnDOT, with the greatest amount going to bridge construction at $376.5 million. The two-state project includes new roads leading from the bridge in Minnesota and Wisconsin, money set aside for water quality studies, and provisions for cultural and historical resources.

Construction of the bridge hasn't been without other hiccups. The original metal fabricator, J&L Steel of Hudson, Wis., left the job after complaining that designs for steel framing were flawed, leading to the same work being done over and over.

Wilber, speaking then on behalf of Lunda/Ames, acknowledged problems in fitting steel, but said they constituted less than 1 percent of the total cost.

At the time, Beer said he expected some unforeseen problems given the bridge's size and complexity.

Kevin Giles • 651-925-5037