Featured Article: Intelligent vehicle systems defy bad weather

Better Roads Staff

 

iPlowing

iPods are for more than just downloading and listening to your favorite songs. Some U.S. agencies are now using them for Audio Route Technology (ART) — essentially turn-by-turn instructions for snowplow drivers. The instructions can be pre-recorded and traded around. “It’s a lot cheaper than getting a GPS turn-by-turn,” says Bill Hoffman, chief maintenance and operations engineer for the Nevada Department of Transportation. “And a GPS unit might not take you on the exact same plow route each time. It would try to calculate the shortest or fastest distance.”

Hoffman says, although a GPS unit is a great asset in some situations, for a snowplow route, “it doesn’t dial operators in to the level of details a driver usually needs.” With ART, special instructions could be included such as, “This pavement is usually five degrees cooler so application rate should be increased,” or “Railroad crossing ahead; Please lift your plow,” Hoffman points out. “Direction for each and every plow route can be specifically recorded and timed at an approximate plow speed. If someone gets sick, a substitute could just take the iPod and take it on the route.”

Hoffman says he finds this technology so valuable that he is trying to kick-start implementation of it in Nevada. “People know about the benefits,” he says. “I just need to get them to sign on the dotted line. In the winter maintenance community, we are trying to link technology and performance to safety and mobility in the winter. It’s up to winter maintenance transportation leaders to find ways to communicate with public and top transportation officials the need for [continued and increased] funding.”

 

Blades: It’s not a case of one blade fits all

In fact, the size, material and configuration of snowplow blades have a pretty big impact on how efficiently and effectively roads and highways are cleared, and the Iowa Department of Transportation (Iowa DOT) has been experimenting with just how unique blade configurations can be, says Bret Hodne, public works director for the City of West Des Moines, Iowa, and a current member and past chairman of the APWA Winter Maintenance Committee.

Typically, a plow blade has three elements that make it effective: the cutting angle, down pressure and the thickness. These three components affect how well a blade can cut through snow and ice. “If you try to cut a piece of meat with a dull blade that was 2 inches thick, it would be hard to,” Hodne says. “The thinner and sharper the blade, the more effective it is. It’s the same principle with a knife. You want to be able to slice down through snow and ice, and if you get some down pressure, you can provide better cutting action.”

Front plows typically use the weight of the plow, while a motor grader or underbody scraper will provide down pressure, Hodne explains. “If you can get an optimum blade with down pressure, it promotes excellent cutting action.”

The Iowa DOT and the City of West Des Moines have been experimenting with various types of blades such as the Joma, manufactured by Black Cat. “Both agencies have been using the Joma blades and have had really good success with them,” Hodne says, adding that the price has been falling on the blades so they are becoming more cost-effective for agencies to use.

The Joma blade is mounted by means of a bushed rubber mounting, so there is no metal-to-metal contact between the blade and the plow, which allows the blade to absorb shock transmitted from the road surface. This shock-absorbing feature, in turn, protects the insert from severe impact, so it allows a longer insert life which results in longer wear life. Hodne says that the rubber mount also absorbs most of the vibration — also known as “chatter” — that would normally be transferred to the plow and the truck. Vibration can be a chief cause of many structural failures and also contributes to operator fatigue, so the reduced “chatter” makes it less noisy and more comfortable for plow operators, Hodne says.

The City of West Des Moines has also found the use of a Kyuper blade — ceramic with carbide embedded in it — to be effective in snow and ice clearing. “It’s the same principle as with a single steel blade, but there is greatly increased wear life,” Hodne says.

The biggest experiment going on currently with multiple states has been DOTs working with a handful of snowplow manufacturers (Monroe Truck Equipment, Falls Equipment, Henke, and Viking) in the quest to develop an optimum snowplow configuration. One prototype plow includes a front-cutting blade, followed by one or two other hydraulically-activated blades behind it that provide a squeegee action to clear the residual slush. A rubber-type blade or blades (Iowa DOT has also been experimenting with triple blades) behind the standard front plow blade controlled by the operator can provide very effective plowing action, Hodne says. “When conditions are optimum, the operator can lower down the secondary blades and take off some of the slush or residual material off and achieve a safer pavement condition,” he adds. v

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