Big derrick barge plucks million-pound iron truss off Hood Canal Bridge
The west truss of Hood Canal Bridge is lowered onto a barge by the DB General, the largest crane barge on the West Coast. -- Photo by Jeff Chew/Peninsula Daily News
By Jeff Chew
Peninsula Daily News
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"Amazing" was a word uttered often on the mostly sunny day as work continued on removing an old portion of the bridge to replace its eastern half.
It was a surreal scene for onlookers standing on the shore at Shine Tidelands State Park, many who waited all day to see the lift that, by engineering standards, was no big deal considering the DB General's 700-ton lift capacity.
Once the 280-foot-long, 70-foot-wide and 40-foot-tall truss was in the air -- almost a million pounds of steel hanging there like a toy -- tugs gently pulled the DB General directly backward. Two other tugs then nudged another barge into perfect alignment under the truss.
The derrick barge slowly lowered the truss onto the barge without a sound.
The DB General "came through big" for the Hood Canal Bridge project, spokesman Joe Irwin said on the www.hoodcanalbridge.com blog Friday.
The bridge was closed May 1 for the project, which is estimated to cost nearly $500 million. It is scheduled to be completed in mid-June at the latest, the state Department of Transportation has said.
On Friday, the lift was originally scheduled at 8 a.m. but hit construction delays, including difficulty torch-cutting through a 3-inch steel plate attaching the truss to the east pontoon and a Navy submarine passing through the more than 1,500-foot bridge gap left by the missing draw span and connecting pontoons.
The truss on the east end of the bridge was removed Wednesday.
Once General Contractors barges the trusses to Tacoma, workers with bridge contractor Kiewit General will dismantle them for recycling.
The new trusses will connect the floating pontoons to the concrete approach roadways that have foundations in Kitsap and Jefferson counties.
The new steel trusses weigh about 1.6 million pounds each -- more than four Boeing 787 Dreamliner airliners, state Department of Transportation officials said.
They will be nearly 100 feet longer and 30 feet wider than the old trusses to match the widened bridge roads atop the pontoons, allowing Transportation to increase capacity on the bridge from two to four lanes.
The trusses are designed like hinges to rise and fall 16.5 feet with the tidal ebb and flow, maintaining the connection between the stationary roadway and floating bridge.
The trusses, the only ones of their kind in the state, are primarily made of structural bridge steel members that range from 20-inches to 42-inches in diameter.
Port Townsend-Jefferson County Editor Jeff Chew can be reached at 360-385-2335 or at jeff.chew@ peninsuladailynews.com.
Last modified: May 10. 2009 12:37AM