Story Photos
 Photo by Bill Wagner Giant off-road dump trucks carry boulders weighing up to 30 tons past the grappling claws of an idel crane on the South Jetty near the mouth of the Columbia River last week. |
Workers nearly finished patching South Jetty
Saturday, August 18, 2007 11:11 PM PDT
By Andre Stepankowsky
Printable version
E-mail this articleIt involved 171,000 tons of rock, including boulders weighing up to 30 tons each, and a fleet of dump trucks and grappling cranes that dwarf the workers running them.
Massive as it is, though, a $21.5 million project to shore up the South Jetty at the mouth of the Columbia River was tiny compared what's needed long-term to protect the structure, which is key to Columbia River shipping.
The South Jetty repair project, spread over two summers, is expected to wrap up by Labor Day, according to U.S. Army Corps spokeswoman Diana Fredlund in Portland.
Sections of the jetty have been badly eroded by wave action and currents, which are strong enough in the open sea to dislodge car-sized boulders and eat away the shoals on which the jetty was built in the 1880s. The Pacific Ocean was threatening to eat right through the segments of the seven-mile long structure, compromising its ability to help keep Columbia River shipping lanes silt-free.
The South Jetty, which juts seaward from Warrenton, Ore., works in tandem with the shorter North Jetty near Ilwaco. The jetties confine the river, creating a flushing action to move sediment out to sea.
The North Jetty had similar repairs in 2005 at a cost of $6 million.
"This work was just to shore up some seriously eroded locations," Fredlund said Friday.
Both jetties need more major rehabilitation, and engineers have previously said that work could cost hundreds of millions of dollars. A study recommending steps to reinforce the structures for another 50 years is due out in March.
The jetties are among the most significant public works project ever undertaken in the Lower Columbia region. They helped tame the notorious Columbia River Bar, often referred to as "The graveyard of the Pacific" for the ships it has claimed, and made it possible for the Columbia to become a major highway for water-borne commerce.
When the South Jetty was built, workers hauled rocks out to sea by building a railroad trestle out into the the open sea. Rocks were simply dumped off flat cars, and eventually the jetty emerged as rock piled up upon the sea bed.
In this repair project, Corps contractor Kiewit-Pacific built a road atop the jetty and used off-road dump trucks and cranes with grapples big enough to grasp a tank. About a 16 workers were involved in the project.
Boulders used for the project were so large -- weighing 15 to 30 tons each -- that they had to be carried out one at a time and came from a special quarry near Sedro-Wooley in Northwest Washington.
Crane operators ordered up rocks of specific shapes, Fredlund said, because boulders need to be wedged together like a jigsaw puzzle to keep waves from jarring them loose.
Though requiring brute force, the project also required careful choreography to keep trucks moving on the one-lane road with turnouts. A round trip from the rock stockpile near Warrenton, then out to the work site and back took about 20 minutes.
This project involved repairs only to the first two miles of the jetty, but the isolated location made equipment maintenance challenging. The threat of swells swamping men and machines was a constant concern, Fredlund said.
The work site had a kind of savage beauty: The scene could be awe-inspiring but frightening because of the power of the ocean.
"I sure understand why they tell people not to be out there," Fredlund said. "It is a scary place."
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