To meet regional growth and corresponding increased load requirements, crews on this $40-million project turned to technology to help solve significant space restrictions. The project replaces a 1920s substation, which needed to remain in operation during construction. The new substation had to be located between the existing substation and the site’s southern boundary. The permit required the site boundary to be set back 15 ft from a neighboring levee, and city zoning for an adjacent industrial site required an additional 25-ft setback from the site boundary.

“We had real space constraints because we had to keep the [industrial site] fully functional,” says Mike Drew, project manager at Burns & McDonnell. “We also had to minimize the amount of downtime for the various users of this power—hospitals, schools and others in the community.”

Working with vendor Siemens, the team designed a compact 115-kV three-in-one gas insulated switchgear substation. According to the team, the design includes a first-ever application in the U.S. of a Siemens circuit breaker monitoring system. The system allows prioritization of maintenance and detection of circuit breaker-related failures. Future crews can use the system to proactively repair a circuit breaker before a faulty and disruptive operation takes place.

The system also features gas density monitoring that provides advance warning of leaks as well as historical data and generates gas inventory reports. A unique overhead monopole design transitions from overhead lines to gas-insulated substation bushing. The overhead lines spiral down the monopole structure from a vertical to horizontal overhead line configuration.  “I loved seeing the care with which all of these pipes and fittings were put together,” one judge said.

The project also created 13,000 sq ft of open space for future site expansion.

At the inception of the project, the Burns & McDonnell team performed a systematic overview of the project’s scope, with a focus on identifying potentially hazardous tasks, conditions and toxic or hazardous materials. Special training and procedures were developed to perform work activities. “Where we couldn’t mitigate things with design, we had additional workplans that reduce any potential risk down toward zero,” Drew says. During 125,000 worker-hours on the project, the team saw no OSHA recordable incidents and no lost-time accidents. Despite encountering some extreme winter weather conditions, the project was completed three months early and within budget.