Adam Spencer, The Triplicate

The first month of full-bore reconstruction work on Crescent City Harbor's inner boat basin - damaged by a tsunami in 2006 and destroyed by one in 2011 - has progressed like clockwork, with dock pilings being installed at a rapid rate and repairs to rock slope walls more than halfway done.

With many projects under way and with rocks and other construction material being delivered by semi-trucks daily, officials are urging extreme caution and patience in the harbor.

There haven't been any recent accidents, but plenty of close calls, harbor officials said.

With 49 pilings installed in June, Dutra Construction, the lead contractor for the inner boat basin project, is on track to finish drilling around late-September to mid-October if there are no major setbacks, according to the harbor's lead engineer, Ward Stover, of Stover Engineering.

Dutra has been able to install two to three steel pilings every day it drills, thanks to a new technique employed this year, according to harbor district officials.

A more efficient method was actually discovered by accident during the first week of drilling, when the drill bit became stuck inside the piling that had just been installed. The entire piling with the drill stuck inside had to be removed, and after the drill bit was dislodged, the piling was vibrated back into the hole.

Now, Dutra is using a piling as a conductor case to drill the hole and returning to slide the piling into the hole later, according to Stover.

D dock and C dock are structurally complete and have working electricity, but are still in need of water hookups and a few other minor details.

Repairs to the inner boat basin's rock slope wall continue to move at a quick pace, with the wall running parallel to U.S. Highway 101 almost complete. The first step of rock wall work, excavation, has started near A Dock in the southeasterly corner of the basin.

Four-ton armored stone will be installed, providing added protection from tsunamis.

Sixty thousand tons of rock for the inner boat basin are needed, and they're being delivered 20 tons at a time for at least 3,000 truckloads.

A second barge crane and rock slope repair crew arrived recently and is working on the walls at the entrance to the inner boat basin, adjacent to the harbor district office.

Boat traffic to the inner boat basin has been constrained by the position of the barge crane, and skippers are asked to be extra-careful entering and exiting the inner basin.

Rock slope walls at the entrance of the inner boat basin were heavily scoured due to the effect of lots of water being forced through a narrow passage.

The dredging division of Dutra Group said that its dredge vessel, the Paula Lee, is en route to Crescent City and expected to arrive Thursday. Dredging of the outer boat basin, which was filled with silt from the 2011 tsunami, is expected to begin Friday and continue around the clock, as the Paula Lee has other dredge projects to complete this summer in the Bay Area.

The Crescent City Harbor Commission will hear an update on construction work from harbor district staff tonight at 6:30 in the Del Norte County Supervisors chambers.

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