July 29, 2020

The Balfour Beatty project team recently completed two of the longest electrical wire runs on the Caltrain Peninsula Corridor Electrification Project (PCEP), in record time.

As the prime-design builder, Balfour Beatty was tasked with building an Overhead Contact System (OCS) with an alternating current (AC) at 25 kilovolts (kV) to transmit electricity along the 52-mile rail corridor.

Instead of using traditional methods, the team strung the OCS wires using a wire train that enabled them to install the system safer and more efficiently.

The wire train is a self-driven maintenance vehicle, complete with a work platform, four cable reel stands, a wire positioning arm, a hydraulic crane, and an inspection pantograph unit.

Balfour Beatty first used the wire train on the Eagle P3 project, where it proved its effectiveness resulting in significant schedule reductions and significant savings to the project.

Traditional methods for catenary wire installation used to boom and bucket trucks, which impose the installation of the messenger wire and contact wires independently at much lower tensions, followed by the adding of balance weights to bring the catenary up to full tension – a process that can take up to several days for each individual wire run averaging 4,000 feet.  

“The wire train works at a speed of about 1 to 3 miles per hour,” OCS Manager Steve McColl stated. “Although installation speed is ultimately driven by craft workers, we’ve been able to safely complete wire runs in a single day’s shift.”

On the Caltrain project, the wire train’s ability to provide a safer, more efficient, and more reliable method for stringing the OCS wires resulted in simultaneously stringing two wires extending about 5,800 feet in one day – a much higher production rate than traditional methods.

“Our goal was to use the safest, most reliable method for installing the OCS system,” says Davie McCulloch, project construction manager. “Not only is the wire train a significant benefit to our client, it gives us a competitive advantage for safely installing OCS on future rail projects.”