W.A. Chester L.L.C.
If you can imagine fishing with a 3,000-foot line, you can get a sense of what it’s like to lay high-voltage electrical cable underground. You can’t see what you’re doing, and anything could be happening to that line downstream unless you control all the factors faultlessly. The cables are pulled thousands of feet from massive reels through underground pipes from manhole to manhole and then spliced together. Additionally, the carbon steel pipes must be welded together perfectly to allow no leaks or sharp edges that could damage the cable as it is pulled through the pipe.
Then the pipe is vacuumed dry and a vacuum is created inside the pipe. It is filled with a special dielectric oil to promote conductivity and keep moisture away.
“There are some big bucks in this kind of work,” remarks Don Parris, vice president of W.A. Chester LLC. “These big jobs can be $80 million. That’s why you wouldn’t necessarily go underground unless you had to because it is costly. All the digging and fancy preparation of the pipe is not cheap, but then again, it lasts.
“Some of this cable we’re pulling out in San Francisco has been in service since 1948 and still is chugging right along,” he emphasizes. “The only reason they’re replacing it is to get greater capacity from a cable with bigger conductors so they can send more juice into the city.”
For the utilities, power generation or distribution companies that are W.A. Chester’s customers, hanging the high-voltage transmission lines above ground in cities and suburban areas is not an option because of crowding. In many cases, the infrastructure for these underground systems is already in place.
On a recent job in Boston, an extra underground pipe that had been laid previously and left empty for future expansion was utilized for a new cable pull. Handling such long cable pulls becomes an issue as weight and size mount.
“Sometimes we have a crane service pick these reels and set them off on trucks that bring them to us and onto our trucks,” Parris states. “These reels can be huge – 79,000 pounds, 12 feet in diameter and 8 feet wide.
“You’ve got to handle very heavy reels, get them out at the manhole that you’re going to pull the cable into, pull the cable, then tear it down and get out of there in a matter of hopefully an eight-hour shift,” Parris explains. “You can’t be out overnight doing this stuff because the longer the cable is exposed, the greater the hazard that it might get rained on or something big could happen. So we have the system set up to be very efficient to handle these big heavy reels.”
The recent job in Boston job entailed cutting-edge techniques. “Every job is different, every job has its own set of challenges, but we built some new equipment for this job that’s better than anyone else in the industry would have by a considerable margin,” Parris asserts.
For the Boston and San Francisco projects, the company used heavy-duty trailers, each one loaded with a huge reel on which was spooled one of the three cables laid together in the pipe. “They back up one another to keep the length of the overall setup down to a reasonable distance,” Parris explains.
Electronics on the trailer measure the condition, tension and speed of the cable as it is pulled. Three high-definition video cameras document the condition of the cable as it comes off the trailer to go into the manhole.
“I don’t think anybody else is doing that in the pipe cable business,” Parris explains. “All of that is captured electronically, and we watch it as we go along and make sure nothing is going out of whack. At the end, we make a series of charts of all this information to give to the client so they are comfortable that the cable was never overstressed.”
The underground pipe is tested to ensure that the bends in it are not too sharp. Welds are tested with X-rays. Pressure tests ensure no leaks are present. Vacuum pumps dry out the pipe. All these precautions are taken to reduce cable failures. Splicing of the cable is a specialty few people in the world can do.
Pipe inspection technology has progressed over the years to the point where it now uses video developed for water or sewer inspection inside the pipe itself. “Their systems really aren’t that well-suited to what we do,” Parris insists. “We’re building our own. It will be unique. No one else will have that capability.”
Besides innovation, the corporate culture of W.A. Chester includes quality. “We have an emphasis on doing a quality job, servicing our client the way they might have been serviced in the 1950s,” Parris says. “I’ve been told we’re like a 1950s company.”
W.A. Chester says that it goes above and beyond with each of its projects. “Because a failure would be so costly, we go to greater pains to make sure everything is right,” Parris says. “It’s not a commodity business, it’s a quality business we’re in, and hence, we take our time more – making sure it’s done right – than most construction companies would.”