A Mountain of Work

Fifteen minutes up the Snow Bowl work road, over rocks and ruts and through ankle-deep mud, four men are engineering the removal of the enormous wheel that holds the cable at the top of the Bailey Falls lift. It’s just a few minutes past eight in the morning and these guys have been at it for an hour already, confident that they can remove the 6,700-pound “bullwheel” before the day is out.

Rob Swift, Snow Bowl mechanic, atop the bullwheel

Built in 1987, the Bailey Falls triple-chair lift serves the “back side” of Worth Mountain. Its cable holds 115 chairs and extends over three-quarters of a mile up the mountain, and on this mid-summer morning, Snow Bowl employees are taking the tension off the cable so they can slip it off the bullwheel.

After 24 winters of service, the bearings inside the bullwheel are starting to wear out, so the major project at the Snow Bowl this summer is to remove the wheel, replace the bearings, and put it all back together again. It’s a major job, not only because the de-tensioning of the cable involves the use of heavy equipment and bolts that require precise amounts of torque, but also because the steel bullwheel is 13-feet in diameter and requires an excavator to lift it.

Once they got the bullwheel up and off its shaft and safely on the ground, the crew dismantled the housing that holds the shaft and bearings. They soon discovered that the upper race (one of the grooves inside the bore in which the bearings roll) had shifted. This requires an overhaul of the bullwheel’s bore, a project that has taken a machinist working within tolerances of two- or three-thousandths of an inch several days to complete.

At the Middlebury College Snow Bowl, five full-time employees are busy tackling a to-do list of maintenance projects large and small every summer.

“The summer months are when we make certain that our lifts are safe and reliable,” said Snow Bowl Manager Peter Mackey ’74. “It’s when we work to ensure that our equipment doesn’t break down over the winter. Because no matter how well lubricated and well maintained your equipment is, moving parts do wear out.”

The biggest category of summer labor at the Bowl is called “line work.” The simplicity of the name belies the complexity of the work. Once a year, according to national and state safety codes, the position of every chair on every lift has to be moved. This reduces the possibility that a grip holding a chair could cause a cable to wear out prematurely. Each grip gets released, moved a set distance, and re-tightened. Snow Bowl personnel do this every summer for all 296 chairs at the mountain.

Also, the code requires that 20 percent of the chairs and grips have to come off the cable for non-destructive testing, or NDT, performed by an independent testing laboratory. Called “magnaflux testing,” it involves the use of dyes, magnetism, and a black light to search for cracks or flaws that could compromise the integrity of each grip.

If any single grip fails, the Snow Bowl has to take down another 20 percent of the chairs and submit to another round of testing.

When all the grips are back on the cable, they are slip-tested using a hydraulic ram to make sure they do not slide on the cable.  Finally, the crew spray-paints a mark on the uphill side of each gripping mechanism so they can see if any of the chairs move during the season. The cable itself is lubricated in the summer, and a certified inspector spends a day at the Bowl examining the cable, grips, and splices.

Line work also includes annual maintenance on the sheaves, or guide wheels, located on top of every tower that holds a cable at the Snow Bowl. Traveling in a work chair, the Snow Bowl crew stops at every tower top, uses a mechanical device to take the tension off each sheave, and spins each one by hand to make sure the bearings are not worn out. Every sheave and sheave assembly must be greased. And just in case there are problems, the crew carries replacement sheaves in the work chair so the worn-out ones can be switched out on the spot.

Summer at the Snow Bowl also means inspecting the bearings in the gearboxes that drive the three lifts and sending the gearbox oil to a lab for testing. The crew also performs annual service on the snowmaking air compressors, and on the entire fleet of motorized vehicles used at the Snow Bowl and Rikert Ski Touring Center including four trail groomers (“snow cats”), two one-ton trucks, a pick-up truck, five snow machines, and assorted tractors and four-wheelers.

“And,” said Peter Mackey exhaling, “don’t even get me started on the mowing. We spend almost three weeks this time of year cutting down the growth at the Bowl. Can you imagine? Some people think that mowing is all we do up here in the summer.”

When all the maintenance projects are completed, the Snow Bowl is ready for its annual inspection performed by the Tramway Division of the Vermont Department of Labor and Industry.

The Bailey Falls lift looking east toward Hancock

 

 

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