CAPE DISAPPOINTMENT — Workers have placed about 18,000 tons of rock on the North Jetty at the mouth of the Columbia River over the last few months. That’s about one-seventh of the total amount they plan to place by next fall.
The project is on schedule and should wrap up for this year in late October, Army Corps of Engineers spokesman Jeff Henon said on Aug. 3. After a hiatus during the winter months, work will resume in March 2019 and continue through November 2019.
River vs. jetty
The three jetties at the mouth of the river were built between 1885 and 1939. They’ve each received periodic updates, but the notoriously rough conditions on the Columbia Bar have taken a toll. Waves constantly batter the rocks, and river and ocean currents eat away at the jetties’ foundations and change the contours of the shipping channel. The jetties play a critical role in the region’s economy by making it safer for ships to navigate the Bar.
The Army Corps finished refurbishing the mile-long “A” Jetty in 2017. Work on North Jetty, which is located near Waikiki and Benson beaches at Cape Disappointment State Park, began in February. Restoration of the South Jetty will commence in 2019 and last through about 2023.
Pieces of a puzzle
The Chico, California-based marine contractor J.E. McAmis was awarded a $27.8 million contract for the project, which consists mostly of placing a total of 140,000 tons of rock on the jetty.
According to Henon, the stones are barged from a quarry in Bellingham to Fort Stevens State Park in Oregon, where they’re loaded onto tractor trailers by crane. The largest stones are about the size of an SUV, and weigh as much as 60,000 pounds, Henon said. When a barge arrives with new stones, truckers have to make about 40 trips a day to transport their cargo to Cape Disappointment. There, another crane crew offloads the rocks to a staging area.
At the jetty, workers do a quality inspection on each rock, then mark it with spray-paint to signal that it is ready to be placed. A crane operator moves the stones from the staging area to the work area, where workers use an excavator with custom jaws to put the stones on the jetty.
“When the jetties were first constructed, stones were dumped on top of each other, but with modern technology the stones are now carefully placed so that they interlock like a puzzle, which makes the jetty more resilient to wave action,” Henon said.
Everything falling into place
The number of people working on the project varies, depending on what kind of work is happening. But most days, there are 10 to 20 workers. These include crane and excavator operators, spotters and project managers and engineers from J.E. McAmis. The Corps also has project managers and engineers overseeing the construction.
So far there has been only one minor accident, Henon said. On July 23, an operator made an error that caused damage to two lattice support beams on a crane. It was repaired onsite and returned to work the following day. There have been no significant worker injuries to date.
Once the jetty construction is done, crews will restore the site by removing equipment and replanting vegetation, Henon said.