WENATCHEE — Darth Vader-like breathing sounds from the communication system inside the Chelan County PUD’s dive trailer amid gauges, timers and computer screens.
Team supervisor Vance Fletcher gazes at underwater images of Rock Island Dam projected from two submerged divers’ helmet cameras.
His instructions to them are concise, but delivered with the camaraderie of a truck driver over a CB radio. Their breathing sounds and quick responses tell Fletcher that all is going well with the dive.
“Hello, Mike. Give us an estimate of the depth, width and length of the erosion around that pipe,” he says into a microphone.
Learner-diver Mike Ledbetter, responds from about 100 feet underwater. “Around the south side?”
“Yeah, Matt’s going to look at the north…”
“I’m guessing it’s three-quarter length from the corner… and probably goes out 50 inches; about six feet,” Ledbetter says.
“OK. Thanks, Mike. Matt, what do you see over there, bud?”
Journeyman diver Matt Treat describes what his helmet camera is projecting.
“Alright, Matt. Copy that… Get your slack up. Let’s get ‘er down and we’ll get out of there.”
The Chelan County PUD is the only utility in the region that has an on-staff team of hydromechanics that double as specially trained, deep-water divers. It’s a proud tradition that will hit the 50-year milestone next year, and one that draws a crowd.
Diving exhibits at PUD-hosted public events draw throngs curious kids eager to try on the gear and view the team’s dive trailer, complete with hyperbaric chamber to treat cases of decompression sickness.
Yet, despite these recent outreach efforts, few people know the dive team exists.
In fact, neither did the team members, themselves, until they hired on as hydromechanics. All are trained on the job. None had previous diving experience.
The 58-year-old Fletcher is a veteran of 33 years at the PUD, including 22 years as a dam diver. He heads a very tight-knit, six-man team, each hand-picked for his work ethic and temperament. Each receives special training to perform tasks that often require intense physical exertion at depths approaching 125 feet.
Wearing special dive suits topped by 33-pound, fiberglass helmets, the divers resemble the iconic deep-sea divers of decades ago.
The dive program began in 1964 when the PUD hired Bill Harris, a construction-industry veteran who dove at several dams, including Grand Coulee and Rocky Reach.
In those early days, dives totaled a modest 25 to 30 per year, but increased ten-fold starting in 1984 with new federal requirements to monitor and ensure survival of migratory fish past the dams.
The divers today use state-of the art technology and equipment to make around 400 dives a year. Their lifeline to the surface, once just a tube that pumped air, is now a multi-function umbilical that includes cables and hoses for communications, light, camera, hot water to warm the suit and the a breathing hose that supplies a richer-than-air mixture of nitrogen and oxygen, called “nitrox.”
The nitrox mixture allows them to work longer underwater and reduces the chances of decompression sickness, also called “the bends,” when divers surface too quickly.
“This is hard-hat diving,” Fletcher said. “It’s about long, hard exertion under water. This is not an old man’s gig.”
Divers currently range in age from 37 to 52. Those who retire from the team continue their above-water hydromechanic duties, fixing things at PUD dams.
They work together, moving with their dive trailer from dam to dam, as needed, taking turns diving, tending air hoses and monitoring dive operations from the trailer.
Fletcher’s teams have not logged any serious injuries, although a few have had to spend some time in the hyperbaric chamber over the years.
“I’m the guy that keeps everything together, and if something happens it’s solely on my shoulders,” he said. “I’ve got the best guys in the district to work with, when it comes down to it. That’s how it is.”
They clear debris from dam trash racks, perform inspections and carry out underwater repairs using specialized hydraulic or pneumatic tools, including a submergible chainsaw.
The team installed the underwater sensors used around the dams for counting migratory fish.
Earlier this month, they were out at Rock Island Dam working with the aid of a massive overhead crane to lower a “head gate” into place on the up-river side of one of the big turbine units in the dam’s second powerhouse.
The gate, a 30-foot tall, 40-ton mass of steel, blocks flow to the unit for servicing. With the giant head gate in place, hydromechanics will drain the turbine’s chamber to prepare it for a $1.5 million upgrade and overhaul.
The divers inspect the base of the head gate’s water-filled slot to remove debris or other obstructions that could cause the gate not to sit squarely on the bottom.
“That’s the challenge of this job,” said Brent Thrapp, 42, a 13-year PUD hydromechanic who’s been diving for the last six. “Everything you do on the surface — if you do it underwater it’s three times harder.”
This time of year, the pesky milfoil plant packs the dams’ trash racks — large metal grates that keep river debris from entering and damaging the turbines. The divers must remove the milfoil by hand, dropping each fistful into a channel along the dam’s bottom, so a mechanical crane can scoop it out.
To work most efficiently and reduce the time needed to gradually and safely resurface, divers can only spend a limited time under water.
“When you have 28 minutes and you have to get something done, you have to be proficient,” Fletcher said. “We expect these guys to concentrate.”
Divers have found everything from dead raccoons in the trash racks to a water-logged teddy bear, Fletcher said. A small plastic mermaid that one of them found on the riverbottom at Rocky Reach Dam has become a sort of scraggly haired figurehead, now painted with a Fu Manchu moustache and named “Russ” for its so-called resemblance to team member Russell McPhetridge.
Dive-team candidates receive training in dive medicine and standards developed by the U.S. Navy.
They undergo a physical exam and start out with shallow dives, accompanied by an experienced diver. If they take well to the water, the work and the teammates, they head to a dive institute in Seattle for seven weeks of training.
“Learner divers” go down with an experienced diver for their first 11 dives. They need to complete 33 working dives to earn journeyman status. The entire training process can take six or more months.
“These guys right now are benefitting from the guys who came before them,” Fletcher said of changes made over the years to improve safety and efficiency on the job. “We’ve done a lot of different things over the last 10 years to keep divers safe and keep this program going. We’re probably the best-kept secret in the district.”