NRG Intake Forebay Structure Demolition Project

Port of Long Beach, Ca.

Tugboat Vessel Design + Fabrication

Removing a structure that is subsea in order to widen the channel for ships to pass through safely.

Removal of approximately 4000 tons of concrete to depths of up to 52 feet.

Project Facts

• Removed 3045 Tons of concrete over the course of 70 days
• 200-ton elements are lifted using 825-ton crane that we’ve mobilized on our Eel Pt. barge

• When the project is complete the channel will be 52 feet deep
• Curtin Maritime was able to efficiently rig these pieces of concrete utilizing custom design softeners that allowed the straps to safely lift it without tearing on the rough concrete edges

What we’re doing is we’re removing a structure that is subsea in order to widen the channel for ships to pass through safely. What that entails is the removal of approximately 4000 tons of concrete to depths of up to 52 feet. In order to accomplish the demolition of the structure, we mobilized dive teams that perform core drilling in specific locations on the structure.

NRG Intake Forebay Structure Demolition Project

The entire time the divers are drilling and tending the wire saws or rigging they’re in constant communication with the lead diver at the surface who is relaying information to the Curtin Maritime team to make sure that we’re performing demolition within the tolerances of the specifications.

This project was substantial enough to Curtin Maritime that Martin Curtin; the C.E.O. actually stepped in as barge master in order to facilitate the communication and make sure that it was being done as properly and efficiently as possible.

We then utilize those core drilled holes to run underwater wire saws and cut the structure into approximately 200-ton elements that will be lifted out from underwater. Those 200-ton elements are then lifted using 825-ton crane that we’ve mobilized on our Eel Pt. barge. One of the requirements of recycling the concrete was that it be clean concrete and the marine growth needed to be removed from it in order to deliver it to the Long Beach facility.

We offload them at Pier S where the shore side crew receives them. One of the limitations of lifting concrete in such large sizes and weights of 200 tons is rigging. Curtin Maritime was able to efficiently rig these pieces of concrete utilizing custom design softeners that allowed the straps to safely lift it without tearing on the rough concrete edges. Upon receipt of it, they continue to demolish it into smaller pieces and it ultimately gets delivered to the Port of Long Beach’s crushing facility to be recycled. When the project is complete the channel will be 52 feet deep and significantly wider allowing the ships that are passing under the new Gerald Desmond Bridge to continue without risk of damage from the structure being in their path. Curtin Maritime is really proud to be a part of this project because not only does it benefit the Port of Long Beach and the City of Long Beach as a whole, but it benefits Curtin Maritime because it’s right here in our own backyard.