Downtown Omaha businesses and residents are lucky to have a particularly durable electrical system — an extensive network of underground cables and equipment vaults.
So durable is this type of electrical system that rarely does it experience an outage during storms.
Thus, Hurricane Sandy provided what was a first for some Omaha Public Power District employees trained to work on downtown's system — a chance to travel to another community and help it recover from a storm. By contrast, above-ground crews routinely travel to storm-stricken communities as part of the utility industry's mutual aid agreements.
OPPD sent about half of its downtown crew to New York City — six of 14 “splicers.” Along with those workers went a seventh person, foreman Jerry Benedict.
These workers are specially trained, not because they work underground, but because they work with lead cable, the backbone of the downtown systems in Omaha and New York.
Lead cabling is a technology that is decades old, highly reliable but also extremely expensive. It no longer is widely used. Instead, polyurethane cables are in common use.
The lead cables themselves didn't fail in New York. Power was lost when floodwater in the underground vaults damaged the transformers and protectors. It was in these vaults where OPPD crews worked repairing and replacing network protectors.
Omaha has about 250 such vaults in downtown, while Manhattan has about 25,000.
Lead cable requires special expertise because of the weight, configuration of the cable and the greater amount of time it takes to do the work. Additionally, the equipment and cables in these vaults expose workers to live electricity — sometimes as much as 13,000 volts.
Surprisingly, the greatest danger isn't electrocution, but an arc flash fire. As a result, the workers wear fire-resistant clothing, which includes fire resistant shirts and special high-voltage gloves.
When in proximity to energized equipment, they wear an extra layer of fire-resistent clothing and a helmet similar to what welders wear.
Sources: Jerry Benedict and Tom Larsen, Omaha Public Power District