Below the mud: Beneath Chelsea Street's new bridge, another work in progress

The Longfellow Bridge has its design challenges ahead, and the BU bridge has been no picnic for engineers.

But another bridge in Boston – the Chelsea Street bridge between Chelsea and East Boston – is a simple affair. By the end of the summer, the new bridge, designed by HNTB and built by J.F. White of Framingham, may be complete. It may even happen ahead of schedule.

Although the men working with iron above the river are having no trouble, the men who move mud below it have been facing a dozen daunting engineering tasks for over a year.

They’re all trying to figure out how to make the channel for oil tankers wider. Engineers, pilots, tug captains, oil companies, private landowners, and Coast Guard and Army personnel have been at the drawing board for two years now.

The new bridge, after all, will span the more than 200-ft. wide channel without interruption. That’s thanks to two superstructures that now dominate the Chelsea skyline (anyone can see them from the Tobin Bridge). So the bridge, when opened, might be wide enough to fit a “Panamax” oil tanker headed to the Gulf, Irving and Global tanks upstream.

Since the tight turn through the old bridge’s narrow opening deemed it a hazard to navigation back in 1992, ship captains have dreamed of a new bridge that would allow such passage. The wider the tanker, the more oil it can bring per visit. The more oil, the more savings there might be for drivers at the pump – or at the airport, in the case of jet fuel.

Congressman Michael Capuano fought to secure $120 million in funding for the bridge. By 2008, fifteen years had elapsed without the Truman Hobbs Act—which guarantees money for such progress—getting the state a nickel in federal funding. In that time, there had been a few bumps and bruises as tankers and tugs made their way through the narrow old bridge. Look over the side of the bridge and you can see its wear and tear from too many tight squeezes.

"The impetus to fix the bridge was to widen it so that the bridge would no longer be a hazard to navigation," said Capuano's spokeswoman, Allison Mills. "That will be accomplished. In order to take full advantage of the new bridge, it will be necessary to widen the channel [below]. I expect that whatever outstanding issues exist will be resolved."

In January 2010, the U.S. Army Corps of Engineers, which digs up plenty of mud in rivers each year, issued an engineering opinion on the matter. They said that while the new Chelsea St. bridge might be wide enough, the waterway beneath it might not be. If a dredged 200-foot-wide channel isn’t possible, some suggested, 175-feet might be. That still might be enough room for those Panamax super-tankers.

Gregg Farmer, the President of the Boston Harbor Pilot Association, is one of the pilots who navigates those tankers up the Creek.

Farmer was as frustrated as anyone else last year when the Army’s opinion came out. "The whole reason the bridge is getting built is because it's a hazard to navigation, and here we are spending 125 million of yours and my money, and we're not getting the channel right," Captain Farmer said.

Dredging tons of mud from a 200-foot wide creek is an unpredictable business. And there are a dozen or more private landowners whose land includes walls on the creek, walls that might collapse with too much tinkering of the mud beneath them. Then there’s the Mass. Water Resource Authority’s water line that runs under the bridge. Over the winter, stakeholders discussed whether that line would have to move.

Finally, there’s that old troublesome 45-degree bend in the river, which requires a hairpin turn for a 600-foot tanker accompanied by three tugboats. A channel must be marked for that turn, one that will require a buffer zone of some meters on either side.

Army Corps project manager Mike Keegan knows every inch of the river bend in question. At the January 19 meeting of the Port Operators Group, the who’s-who of Boston Harbor stakeholders, Keegan laid out the work still left before a possible 175-foot channel could be dredged.

Keegan has worked to coordinate with federal and state agencies since 2009. After the new bridge gets built and the old one taken down, he says dredging can begin.

“You don't just draw two lines on a map and say ‘there's your channel,’” Keegan said in a phone interview last summer. “The bulkheads are old, and the mudline is 12-13-feet deep. You're talking about removing 20 feet of mud to get to a 38-foot deep channel, and you can't assume that you can cut it vertically. If you dig a hole in organic material, it's going to slough off and the wall will collapse.”

Before the Army moves an inch of mud, they need design plans from engineers and permissions from every landowner along Chelsea Creek. That has taken several months to do and still wasn't done by this spring, according to Keegan.

Over the winter, John Vitagliano, HNTB’s consultant for the bridge, had been working to get the MWRA’s line moved, too.

Vitagliano is used to complicated projects. He was the city's traffic commissioner for Mayor Kevin White in the 1970s.

"The information gathering process is underway right now, and I'm spearheading that,” Vitagliano said in a phone interview last fall. “We have to have it together in the next few months, because to put together an appropriate dredging program, it needs to be synchronized with bridge construction,” he said.
All that behind-the-scenes planning continues while the bridge continues to rise over Chelsea.

With a 200-ft. span over the water, it would be a disappointment for all parties if that money were spent with no significant improvement to commerce beneath the bridge.

"The consensus is that widening [the channel] to 140 feet is not good enough,” said Coast Guard Lieutenant Commander Pamela Garcia, who regularly attends the bridge meetings on the Coast Guard’s behalf. “It's not safe, and it's not an improvement.”