Bridge backers give a Knik Arm tour

July 15, 2005

DAWN DE BUSK\Frontiersman reporter

KNIK ARM -- Mat-Su's deep-water dock stands as testimony to the feasibility of a proposed bridge that could withstand Knik Arm's extreme tidal currents and heavy ice floes, according to the deputy executive director of a government entity formed to tout construction of such a bridge.

Darryl Jordan of the Knik Arm Bridge and Toll Authority on Tuesday aimed to illustrate the feasibility of a Knik Arm bridge by inviting media reporters and photographers aboard a twin-engine vessel for a cruise around the Arm, viewing spots where a proposed bridge might cross the gun-metal gray water.

The tour, which left the Port of Anchorage's small boat launch, included zipping over to Eagle Bay, where the Eagle River empties into the Arm, and an up-close view of Port MacKenzie's $14.7-million dock.

Whale-watchers nestled on the bluffs on both the Anchorage and Valley sides of the Arm. A skiff of workers readied a net to capture sea-creature samples for studies associated with the proposed project's environmental-impact statement. From various angles, sunlight sparkled on the water and threw a rainbow behind the boat's engines as the tide ebbed and flowed during the two-hour ride.

"This reminds me of Chesapeake Bay when it's like this -- beautiful, calm, warm," Jordan said.

Of course, most of the year in Knik Arm, weather is not described as warm and the water cannot be called calm. Structures like oil platforms, which are built in the water, must contend with tidal action, ice floes and wind. Not to mention Alaska's seismic activity, which knows no season.

"The bridge is programmed to go in water that's more shallow and has less current," Port MacKenzie Port Director Marc Van Dongen said in a phone interview Wednesday.

Jordan hesitated about getting too specific about designs for the proposed bridge, saying he would delve into that matter after completing and reviewing the environmental impact statement. Without an approved EIS and $200 million in federal transportation money being pushed by U.S. Rep. Don Young, R-Alaska, the project doesn't exist.

Jordan admired the dock on the Mat-Su shore and asked fellow boaters to imagine multiplying the 400-foot structure 20 times . That's also how Jordan arrived at the $400- to $600-million cost for the project.

Jordan focused his energy and conversation on a proposed route for the bridge, where it would connect to the Valley side and where it would tie into Anchorage.

One prime location for the Mat-Su approach could be about a mile north of Port MacKenzie, near Anderson Dock. Jordan said Carl Anderson, the former tugboat operator who reportedly owns the property might be willing to sell.

If the three-lane bridge came in near Anderson Dock, it would be less disruptive to dock activities at Port MacKenzie. However, connecting a new road system to that area might require filling in wetlands.

A second, shorter corridor takes advantage of existing roads, Jordan said. The proposed bridge traffic could travel to the middle of the port's industrial zone.

The Port MacKenzie connection shaves one-quarter mile off the route.

Also, the sea floor there is more compact, creating a more stabilized bridge without driving the piles as deep, Van Dongen said. For example, piles for the Mat-Su-side dock went 38 feet into the ground. Those piles received the required number of design blow counts -- the number of times the impact hammer hits the pile.

"If it takes 50 hits to go three inches, that's good," he said.

At the Port of Anchorage, where the new Ship Creek Bridge is being built, they drove piles 220 feet down and still didn't get design blow counts, he said.

"The earth is very well compacted. Millions of years ago, the Elmendorf Moraine used to be a 250-foot earth bridge that went across the inlet," he said, referring to the proposed bridge route across the narrowest part of the inlet.

Van Dongen said the bridge could use the same design as the dock: Batter piles, or piles at angles, reinforced with I-beams and concrete, capable of breaking up ice in the inlet.

The dock builders came up with value engineering, he said. "The original plan called for sliding rebar into the pilings, which is very difficult. We thought the I-beam would be better and easier to construct," he said. Construction crews welded four I-beams together in the shape of a cross, slid it down inside the piling and filled it with concrete, he said.

"We brought our first ship in during the coldest week of the winter. The ice went from 6 inches thick to more than 2 feet within about three days. The dock handled the ice," he said.

Could this grand-scale project really happen?

"I'll believe it when I see the money," Jordan said.

He heard promising comments during a workshop on project financing that was held in Boston. There were more than 40 state highway officials learning how to obtain bond revenue for transportation projects, he said.

"I was surprised that everyone in that group had heard of the bridge project. Our project does have national attention," he said. "Many people said that because of Don Young's chairman position, he will get what he wants."

Contact Dawn De Busk at 352-2252, or dawn.debusk@frontiersman.com.