August/September 2009 Pond/Canoe photo by Becky Hart
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Vol 25 No 6
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Cable guy Phil Karper zips and dips for data
Hydrologic technician Phil Karper muscles his cable basket back across the Missouri River after taking river-current measurements. Starting out, he zooms across the river to get as high up the other end of the curve a possible. [Photo by Craig Larcom]
By Craig & Liz Larcom Phil Karper stands in a small cable car, ready to release the brake and start sliding through the air above the Missouri River, just downstream of Morony Dam, near Great Falls. Down below, melt water races downstream. The hydrologic technician from Helena hollers, “Are you ready?” at the photographer who stands nearby, hoping to catch the action. At the sound of, “Yep,” Karper the cable guy shifts his hand and suddenly the car is zooming down the line across the river, and then slowing as it climbs the other side. From the far side of the river, Karper is ready to begin an hour and a half of measurements for his employer, the U.S. Geological Survey. About 30 percent of the places Karper monitors have a cable car. The rest are measured from bridges, or in the case of small streams, waded. The one at Morony, where he is substituting for a fellow worker this particular day, delivers an especially quick ride across the river. Tramway cable makes the difference. Other sites use wire rope, which, being rougher, doesn’t let the cable car slide so rapidly. Karper remembers when the cable was installed. “We repaired the cable with a wire patch after a bullet hit it, but as soon as there was a safety inspection they replaced it,” he remembers. He wasn’t concerned about the cable’s safety between the damage and the replacement, though. “There was plenty of cable left. That cable’s way thicker and stronger than it needs to be,” he says. For the first half of the work above the river, Karper releases the brake to move to the next stop, typically one of 25 or 30 current measurements that he will make on the way back. When he reaches the bottom of the sagging cable, he has to ratchet himself back up the rest of the way by hand, continuing to stop and take measurements as he goes. “I haven’t worked with anyone who didn’t have enough muscle to do it. It takes some effort though,” he says. His procedure is to take a reading on an outside gage when he arrives on site, then check inside a little house that protects some equipment, to see if the recording gage agrees. A seismograph-like device, it records time versus the depth of the river where the gage’s sensor is set. He checks the batteries, sees that the clock has the right time, and then checks the outside measurement again. Then he jumps into the cable car to measure the river’s flow with a current meter. He also measures depth, to learn what’s going on beneath the surface of the water. “The bottom of the river changes throughout the year,” he points out. To keep the measurements accurate to within five or ten percent, technicians visit many (Continued on page 31)