Caltrans crews clearing an avalanche from Highway 50, along the summit area, around what is called Frog Pond. Courtesy of Darrell Uppendahl, CalTrans.


Outside with Charlie: An inside look at snow control on Highway 50

By From page A11 | April 06, 2012

From the early snow in Autumn to the closing day at Tahoe ski resorts, you’ve been heading up Highway 50 for fun on the slopes and in the back-country.

Through rain, wind and all kinds of snow storms over Echo Summit, you and yours have made it to Sierra-at-Tahoe, or into the Lake Tahoe Basin, safely, every time.

How is this possible? From Placerville to Riverton, 50 its four lanes, uphill till just east of Pollock Pines, and then it’s downhill again to Riverton. From there it is a two-lane, twisting mountain road, in the American River Canyon, uphill to Echo Summit, before dropping into Tahoe. From November to May it’s likely to snow from a little to quite a lot.

Keeping 50 open during snow season is a multifaceted task, a finely tuned dance between Caltrans and Mother Nature. Darrell Uppendahl, a 26-year Caltrans veteran, coordinates the dance and is in charge of making sure that the road is open and safe.

Caltrans starts to get its crews ready by about October 15 each year. The season for plowing snow generally ends by May 1. There is a core of 35-40 permanent equipment operators and an additional 40 or so are brought on for the season. During a vigorous storm, another 25 to 30 operators are added.

The season begins with a review of policies, safety procedures, chaining classes, and assignments. Every driver shows up already qualified to operate the various pieces of equipment needed. Newbies generally put in quite a few hours in the smaller trucks, and are mentored by veteran operators. Moving to bigger plow trucks comes with experience. Moving these big trucks through snow takes a good bit of skill.

Caltrans uses three main pieces of equipment to keep the roads clear: 5-ton dump box trucks with plows, most with side mounted “wings” and rear mounted sand spreaders, road graders, and rather impressive rotary plows. The trucks, with all the trimmings, cost in the neighborhood of $225K. A road grader, in the $150K range. Those fantastic looking rotary plows? Around $400K each. They are worth every penny.

When the snow starts to fall, the crews head out to cover assigned routes with a lead worker on each route. For instance, one route would be from Camino to Pollock Pines, another from Pollock Pines to Riverton, and so on, up through the American River Canyon to Lake Tahoe. Uppendahl said that the routes are established like this so the trucks can prevent a build-up of snow on the road. It’s all very flexible though. As the snow level moves around, so do the plows. Plows travel in teams of two or three.

Plow trucks do most of the clearing work. They can only push so much snow to the side of the road before the road needs to be widened, and depending on the storm, ice and snow build-up may need to be removed. This is especially true on the two lane road through the American River Canyon.

The road graders come in at this point, as they can get down to the road bed, and are able to push more snow to the side of the road. The big rotary plows come along and throw the snow that’s pushed to the side off the roadway entirely.

The plow trucks continue to work the road, doing spot clearing, and spreading sand, long after the storms are gone. Until the road is clear and dry, the teams are out there.

The storms dictate how the crews work. There are two 12 hour shifts, 6 am to 6 pm, 6 pm to 6 am. There are very few breaks involved in the day. For as long as is needed, the crews work these shifts. There is no limit, as keeping up with the snowfall is critical. When the storm is over, and the roads are clear, everyone gets some down time, but only then.

During the storms, the plows have to be fueled, and if necessary, repaired. It’s all done as efficiently as possible. The mechanics who keep the plows running work long days as well. A broken down plow doesn’t do anyone any good.

Caltrans maintains a dorm in South Lake Tahoe. There are 24 beds, bathrooms, and a fully equipped kitchen. A staff of four cooks, along with cooks helpers, are stationed here. A shop, fully loaded with the parts needed to keep the plows working, along with the mechanics, complete the set-up. When the snow is falling, the comings and goings of drivers and mechanics is a steady flow of skilled workers.

Caltrans moves chain control up and down the highway as needed. It can be perplexing to anyone having to put chains on and then finding themselves driving on a road without much snow, or driving into an area where the snow seems to have left the roadway.

Uppendahl points out that Highway 50, heading east out of Placerville, generally is uphill. Leaving Pollock Pines though, it is downhill to Riverton. The elevation drop is sometimes enough for the snow to turn to rain, or very slushy snow. It is a steady uphill from there though, and the need for chains becomes apparent not far up the road.

He and Ed Ingram, 32 years with Caltrans and Supervisor of the Placerville area, said that the chain control points along the highway were established long ago. They both said that the old timers choose well, and there has been no need to move them over the years.

One of the last places for chain control before getting into the American River Canyon is Pollock Pines. Traffic is sometimes held here while work continues on the highway. Uppendahl said having traffic come to a standstill in the canyon means that the plows can’t plow. The result is a build up of snow and ice on the roads, which simply makes for a slippery and unsafe situation.

The highway is rarely closed during a storm. When it is, Pollock Pines and Meyers are typically the places where motorists have to wait. The reason for closing the highway is very simple: safety. In all things related to keeping 50 open, safety is paramount, according to Uppendahl.

Echo Summit is where Highway 50 hangs onto the granite cliffs above Christmas Valley, Meyers and the Lake Tahoe Basin. It is steep, and avalanches are a constant concern during snow season. When Highway 50 is infrequently closed during a storm, it’s most likely due to avalanche control.

Caltrans prefers to trigger avalanches rather than have them occur on an unknown schedule. Long ago, crews would throw hand charges down onto the slopes from the ridge high above the road. At the bottom of the grade, just outside of Meyers, there was an old gun mount. A 105 millimeter recoilless rifle was mounted there, and the crews would also fire rounds onto the slopes, triggering avalanches. While these are sometimes called controlled avalanches, in reality there is no such thing. They are simply unpredictable.

The 105 millimeter rifle is gone, and the crews no longer hike to the ridge and toss explosives over. In place of that, there are 11 Swiss made Gazex avalanche control canons spaced out along historic avalanche spots along the summit. These “canons” are propane fired, and are computer controlled from South Lake Tahoe.

The gun mount station at the bottom of the grade has been rebuilt and looks like it might be a nice cafe.
There is a small air propelled canon behind the double doors that face the cliffs above Highway 50. It fires an 80 millimeter shell, and is used only as a back-up in case the Gazex system is down. There are some spots that the it can’t reach, so keeping the Gazex system up and running is very important.

Once an avalanche has been triggered, the crews swing into action, clearing the snow from the roadway with loaders, rotary plows and trucks. While they prefer to do the avalanche control early in the morning, when there is very little traffic to hold, reality is that this task is done when necessary.

Consider that somewhere around 20,000 cars per year head to Tahoe on 50, in all kinds of weather. The economies of communities along the way, and into Tahoe, rely heavily on the ability of travelers, year around, to arrive safely.

Uppendahl stressed that keeping Highway 50 open in snow season is always contingent on safety first, for his crews, and the motorists who use the road.

Next time you get to drive to your favorite resort, or favorite back-country skiing spot, during a snow storm or just after one, you have over 100 Caltrans equipment operators, mechanics, cooks, supervisors, some very good, big equipment, and a few explosives, working around the clock, to thank for the experience of doing so.

Charlie Ferris

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