Preparing a Port for Larger Container Ships

Wilmington, NC 

i+iconSOUTHEAST is performing numerous structural improvements as part of a $29M multi-phase project for the North Carolina State Ports Authority’s Berth 7 in Wilmington, NC. The port is upgrading Berth 7, which was built in the mid-1960s, in order to accommodate larger container ships and a larger 100 foot container gantry crane.

This project includes the demolition of the existing wharf and rebuilding of a pile-supported wharf structure to withstand increased lateral loads from the larger container ships. One of the key differences in the design of the new wharf is that it will be built upon 24 inch square piling, versus the previous 16 inch octagonal piling. Also, i+iconSOUTHEAST is adding a 100 foot crane beam needed for the larger gantry cranes.

All work is being performed on a fast track schedule and expected to be completed in 2019. The project is being conducted in a total of six phases to allow for as little disruption as possible to the facility’s operations, continuing to permit existing ship-to-shore container cranes to load/unload at the adjacent wharf and other wharfs at the facility. Additionally, access and use of the warehouse facility needs to be maintained throughout construction.

Piling for the New Berth

Initial phases of the project were related to preparation for the construction and demolition of existing structures that were being replaced. These preparatory phases were completed in 2018. One of the tasks in the early phases was to reduce the current warehouse space to make room for the new crane rail that will be used for access to the cargo. This required the demolition of 84,000 sf of existing warehouse and the construction of a permanent wall to enclose this space. This new east-west exterior wall with overhead coiling doors was installed and a loading dock and canopy were constructed for the warehouse. This demolition was completed 20 days ahead of the required completion date.

In replacing the wharf, a total of 103,000 sf of the previous berthing structure was demolished and will be replaced with a new 104,000 sf pile-supported wharf, as well as fender systems with mooring hardware consisting of new tie-downs and stowage pins for 100-foot gauge container cranes. A total of 682 prestressed concrete piles are needed and currently about half have been driven. These piles are 65-70 feet in length and are driven into approximately 40 feet of water depth using a D62 hammer and one of three Manitowoc 4100 cranes on site. Two pile driving crews are working simultaneously to accomplish this feat, while an additional two carpenter crews are performing the concrete work including the installation of cast-in-place concrete bent caps, crane beams, a front fascia beam, precast concrete deck panels, a cast-in-place topping slab, and two-way flat plate slabs.

Finally new railroad will be installed for two parallel tracks to service the land transportation of the cargo entering the port.

One challenge that this project has overcome was a two week delay due to Hurricane Florence. Luckily the hurricane did not cause damage to the wharf, but it did cause a power outage and difficulty in accessing the site. The project was able to continue and we are thankful that there was only a time delay.