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Pier 3 at MOTCO

LOCATION:

Concord, CA

DESCRIPTION :

This project was a contract with the U.S. Army Corps of Engineers to repair and maintain operational capacity at Pier 3 Military Ocean Terminal Concord, otherwise known as MOTCO.
MOTCO is the Army’s major military cargo shipment port for the West Coast. The project required an underwater pile protection system be installed on 2,055 timber piles within a window of 10 months.

MOTCO terminal is the location of the 1944 Port Chicago Disaster, the worst home-front disaster of World War II, in which an ammunition ship detonated while carrying over 4,600 tons of explosives. The area is considered a Munitions Response Site and therefore, prior to any underwater work, an underwater Unexploded Ordnance (UXO) Munitions/Explosives of Concern (MEC) clearance is required.

Power Engineering paired up with a DVBE UXO/MEC commercial diving company to complete the UXO/MEC clearance. A team of military trained UXO/MEC divers spent several weeks performing munitions clearance that rendered the construction footprint safe for work by Power Engineering’s dive teams.

The quantity of repairs was remarkable and the Power Engineering crew, made up of craftsmen and ADCI certified commercial divers, could now get to work. Here is how the operation was executed despite challenges of strong currents and scheduling at an active military marine terminal:

A two-man support crew, mobilized by boat, started the process by removing any bolts or braces that prevented the wrapping of each pile. With obstructions eliminated, a diver would pressure wash marine growth off of the timber piling. As that diver moved onto clean the next pile, another diver followed and excavated 2-ft of mud away from the diameter of the pile base. (Pile repairs ranged from 9-ft to 40-ft in length – with the repair length related to depth of water under the pier). A third diver, along with a member of the support crew working topside from a float, wrapped each pile with the DENSO North America® SeaShield 90 pile protection system. The DENSO system consists of an inner petrolatum tape wrap and an outer HDPE protective shell. After taping the pile, a fourth diver and another topside support crew member wrapped the piles with an HDPE outer cover for protection of the inner piling tape. Once the divers completed the installation of the protection system, a fifth diver – a 3rd party Quality Control inspector diver, examined each and every pile for confirmation that it was cleaned, excavated, taped and wrapped to specification. This process happened 2,055 times!

Meanwhile, in addition to the pile wrap dive teams, the UXO/MEC dive team remained on UXO/MEC stand-by, on-site, during the entire project. An environmental biologist was also on-site at all times. The biologist monitored the area for marine mammals, sampled water turbidity levels and ensured that all precautions were being taken to protect the environment and marine life.

This was Power Engineering’s fourth project completed on the piers at MOTCO. As with the other projects, this work was completed on budget and on time – despite an 30% increase in the quantity of piles being wrapped – and with no time extensions. There were zero environmental or safety incidents and U.S. Army Corps of Engineers project leaders expressed “exceptional” ratings upon evaluation of the job.