Detours and lane restrictions during the coming years of construction work to replace the Alaskan Way Viaduct will smack Ballard's maritime and fishing industries harder than it will affect other maritime interests south of the viaduct.

That's because Seattle's railroad yards, where freight trains are assembled, are in the Sodo area south of the viaduct. To reach the rail yards, Ballard's maritime and commercial fishing businesses will have to drive through or around the Alaskan Way construction zone, said Dave Gering, executive director of the Manufacturing Industrial Council. His organization advocates keeping industry operating on the city's remaining industrial lands.

Gering made the observation as a panel member at a Feb. 27 transportation forum at West Seattle High School sponsored by the West Seattle Chamber of Commerce and the West Seattle Herald. Joining him on stage were City Councilwoman Jan Drago; Grace Crunican, director of the Seattle Department of Transportation; and Peter Sherwin, formerly a leader of the monorail campaign and now a proponent of a repairing the existing viaduct.

About 150 people attended the forum. It was moderated by C.R. Douglas, host of a city politics program on the Seattle Channel.

A survey indicates Seattle's maritime industry generates $28.5 billion a year, Gering said. "That's more than Boeing."

He called replacement of the Alaskan Way Viaduct "the most disruptive project in state history." Ballard's maritime businesses and its homeport for commercial fishermen would be economically threatened if they couldn't move easily through and around the downtown waterfront for an extended time, Gering said. Many businesses would either move or shut down if the closure goes on too long.

The Manufacturing Industrial Council wants to protect the "through capacity" of the downtown waterfront nexus because it represents shoreline businesses all around Elliott Bay, Salmon Bay and the Duwamish River. Gering worried about getting goods and materials through the waterfront during the estimated seven to 10 years of construction to come.

"If after a decade, we still have no 'through capacity,' it will be a disaster for Ballard and a disaster for West Seattle," he said.

Audience members at the transportation forum questioned the wording of the March 13 ballot, which instructs voters to select either yes or no to building a four-lane tunnel, and yes or no to building a new viaduct.

"You invented this ballot, Jan Drago," Douglas said in mock accusation.

"We didn't want a ballot," Drago replied. "Three times we expressed our preference (for a tunnel)." Then the governor ordered a public vote, and too early at that, she added. Drago would've preferred to vote in April so the hybrid tunnel proposal could be further vetted.

Although she doesn't think there should be a public vote on the matter, Drago warned of the outcome. "You better listen to it," she said.

Peter Sherwin called the upcoming election "ridiculous." He recommended the existing viaduct be repaired in stages, focusing on sections that all agree need fixing.

"Band-Aids lead to healing," he said.

Drago also said three economic-impact studies were done. One said a tunnel would provide "substantial economic benefits." Another study concluded the lengthy construction period would "devastate" the local economy.

An audience member asked, since the Washington state officials have declared the hybrid surface tunnel proposal unsafe, why is it still on the ballot?

Crunican pointed out that the Washington State Department of Transportation published a 1,000-page study in January declaring the hybrid tunnel safe. One month later, higher state officials announced a 56-page study claiming the hybrid tunnel would be unsafe because emergency vehicles couldn't get through its rush-hour traffic.

"With so many studies thrown out, I don't know who to believe anymore," said one woman at the audience microphone.

Several people from the audience, including former Port Commissioner Jack Block, asked about additional water taxi service during the prolonged construction period. That includes money to pay for larger vessels as well as a permanent dock with adequate parking on the West Seattle side of Elliott Bay.

Before the existing Alaskan Way Viaduct is taken down, other transportation improvements will have to be built. They'll include widening the Spokane Street Viaduct, the stretch of elevated roadway connecting the West Seattle Bridge to Interstate 5.

Another planned improvement will be a new Fourth Avenue exit from the Spokane Street Viaduct down to ground level at Fourth Avenue. The ramp will have two lanes: one for cars and trucks, the other for buses, Crunican said.

There also is to be a new overpass planned from Lander Street over the railroad tracks.

All of those changes are to be built before the Alaskan Way Viaduct is scheduled to close in 2011, Drago said.

The best way for West Seattleites to get around during the long construction period will be by bus, Crunican said.

People asked what exits there would be for a hybrid tunnel.

For West Seattle motorists headed north, the main exit for downtown would be at King Street. Drivers would then continue northward on the Alaskan Way surface street and turn eastward to get on downtown streets. It would take about nine months to build the King Street interchange, Crunican said.

There would be another exit at Western Avenue as there is now.

Ballard drivers going south would get off at Western Avenue or at King Street to enter downtown streets.

Another audience member asked how steep the grade would be between the hybrid tunnel and the Battery Street Tunnel.

It would be a 7 percent slope, which is the same as on the West Seattle Bridge, Crunican said.

A man in the audience who said he was a retired civil engineer asked why not repair the existing Alaskan Way Viaduct?

"It would be so simple," he said.

Structural engineers for the state and city departments of transportation considered that, Crunican said. Fixing the old viaduct would cost about 80 percent as much as building a new viaduct, and the finished product would be good for about 25 more years, she said. But if they built a new viaduct, it could be expected to last 50 to 100 years. Officials decided building new would be more cost-effective.

Tim St. Clair can be contacted at tstclair@robinsonnews.com or 932-0300.