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Creating a Dependable Electrical System for a High-Traffic Bridge in Maryland
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Infrastructure Market
By Joe DiGiorgio, Project Engineer
In November, Cianbro completed the Bay Bridge 5kV electrical improvements project, a massive system upgrade for the Maryland Department of Transportation. The project created a dependable electrical system for the east- and westbound bridges spanning the Chesapeake Bay in Baltimore. Not only was the work scope a massive undertaking, but the team also encountered two significant challenges they tackled head-on: Lane closures and weather conditions. These challenges directly affected access to our work areas, and both persisted for the project’s duration. Nevertheless, the team persevered and developed contingency plans to ensure they completed the work on time.
The scope of work included the installation of new structural steel supports for the 5kV and 480V cable, 23 new platforms for electrical equipment, directional boring on the east and west abutments, roughly five miles of new 5kV and
480V cable on land and the bridge, new concrete pads for the electrical equipment, a pre-fabricated precast building, new generator, new integrated SCADA (supervisory control and data acquisition) system, cable relocation on the west-bound bridge (north bridge), and the demolition of the existing 5kV electrical cable and equipment.
During the installation of the new supports for the 5kV/480V cable, the team encountered multiple design issues, which led to modifying and re-installing the supports three times. While installing the medium voltage switches, the team had to plan and execute the operation carefully due to the switch’s size and the space between the steel members on the bridge. Once the team hoisted the switch, they had to finish assembling the platform before setting the switch in its final resting position. Upon review of the new electrical system, MDTA/EOR discovered a weak point within the system, and MDTA granted a change order to replace roughly two miles of 5kV cable on the west-bound bridge, which extended the contract another year.
Due to the complexities of the new electrical system, multiple design issues were discovered, however, the project team, our subcontractors, the MDTA, and the engineer of record worked tirelessly in unison to solve and overcome each challenge.
This job presented several unexpected hurdles and logistical troubles, but it was completed successfully thanks to the dedication of our team members and their commitment to provide quality work while collaborating to ensure each other’s safety. Due to their focus on safety, our team completed the project without any incidents.
