As construction workers looked on, a skilled crane operator lowered a 60-foot wooden pole dangling from a 10,000-pound machine called a vibratory hammer into the water below Blaine Public Pier. When the hammer turned on, the pole sank slowly into the mud below the harbor, and within a matter of minutes a new pile for the pier had been driven.
Repairs to the pier are moving along rapidly, and the dramatic work of pile driving has given way to less visible repairs such as replacing pile caps and decking. The pier has been closed to all traffic while crews replace piles and decking that have weathered and rotted past their prime. Project managers estimate repairs will last another two or three weeks.
Project engineer Norman Gilbert said workers uncovered the problems during a routine inspection. “We do a conditional survey every year, and last year we discovered some dry rot and marine damage to piles, pile caps and decking,” he said. Nine structural piles and seven “fender” piles were slated for replacement. Fender piles encircle the pier and act as bumpers to protect it from floating debris and wayward boats, while structural piles hold up the decking.
The Port of Bellingham operates the pier, which is a popular place for bird watchers, crabbers and picnickers. The repairs are expected to cost approximately $200,000, and IMCO General Construction based out of Ferndale is the project contractor.
Using a large crane and a vibratory hammer, construction workers pulled out the old, rotted piles and replaced them with new piles driven 30 feet into the sea floor. The old piles, covered with barnacles, clams and seaweed, were stacked nearby, offering a giant buffet to throngs of seagulls.
To push the new piles into the seabed, the vibratory hammer shakes them rapidly. “Off-center weights spin and shake creating vibrations which, combined the weight of the hammer, drive the piling down into the ground,” Gilbert said. The vibrations are nearly imperceptible from a distance, but the poles push slowly and steadily into the soft mud below the pier.
Crews wrapped up the pile driving last week, and will continue replacing pile caps, stringers and decking before cleaning up the work site and reopening the pier.
“The project should take a couple more weeks as they replace the last couple pile caps and nail down the decking,” said Blaine harbormaster Andy Peterson. “Folks won’t see as much activity out there as when they were using the crane.”