Omega Morgan slides 3,400-ton Sellwood Bridge on a curve; at 1,100 feet, it is likely longest bridge structure ever moved
PORTLAND, Ore.—January 21, 2013 — Deemed the longest bridge span ever relocated and one of the most complex “translations” ever attempted, the Sellwood Bridge move was celebrated at its successful conclusion Saturday evening, Jan. 19. The most highly traveled two-lane bridge in Oregon, the Sellwood was jacked up a few inches by Portland-based Omega Morgan (www.omegamorgan.com) and slid at an angle to a new position nearby. The span moved is 1,100 feet long and weighs 3,400 tons or 6.8 million pounds.
Omega Morgan won the bid to move the bridge with its plan to save Multnomah County, Ore. millions of dollars and by reducing up to a year of construction time. The company’s proposal was to save the original span by moving it to the side, reopening it to traffic Jan. 24 and leaving room at the original site for construction of a new $307.5 million bridge. The project will be completed in 2016.
The company’s plan was the only one that did not require destruction of the old bridge which would have required 30,500 vehicles a day to re-route miles away to other bridges over the wide Willamette River. Other benefits of the Omega Morgan proposal: include reducing environmental impact and improving safety for bridge users and workers.
The Biggest Bridge Move in History?
Multnomah County encompasses the most populous area in Oregon, including the city of Portland. The 87-year-old Sellwood Bridge project is one of the largest the county has undertaken in decades, according to officials managing the project. Research by the county’s managers say the move was “historic” because the truss is a single continuous structure and it is one of the oldest bridge structures ever relocated in this manner. In a presentation, Multnomah County wrote, “This is one of the longest, oldest structures to be moved in this way.”
“We are proud to be an important part of this significant project,” said John McCalla, Omega Morgan’s CEO/President. “Our employees enjoy a challenge and this one presented several opportunities to test our skills. We are pleased that the move came off smoothly and will save commuter time, construction time and taxpayers’ dollars.”
How It Was Done
Omega Morgan assigned a team led by Vice President of Engineering Ralph Di Caprio, whose experience in executing complicated moves includes the removal of Portland’s Sauvie Island Bridge and installation of the new bridge, managing the Third Avenue Bridge project in New York City, moving two 900-ton spans on the Hood Canal Bridge and the transport and launch of the Kalama River Bridge.
The move took place over 12 hours amidst regional media coverage and thousands of spectators along the river bank. Some of the viewers called the sight “a once in a lifetime event.”
The Omega Morgan crew raised the truss span vertically by several inches and then pushed it north by hydraulic jack-and-slide beams. It was then slowly moved twice as far on the west end (66 feet) than at the east end (33 feet) to accommodate for the new, permanent bridge being wider at the west end, flaring from two to four lanes to add traffic capacity. The truss span was then moved on a radius, along a curving path, adding to the complexity of the execution.
During a news briefing, it was revealed that a common dishwashing soap was being used to lubricate pads on the slides, bringing a moment of levity to the serious, informational event.
CONTACT: Molly Streuli for Omega Morgan, firstname.lastname@example.org; 503-295-1918