A Kramer machine on snow clearing duty
Many countries had their most severe winter for years, but it could have been much worse without the right equipment and technology as Patrick Smith reports
As many countries faced up to the 2010-2011 winter, hard-pressed maintenance teams did their best to keep things moving on the roads. With some of the lowest temperatures and heaviest snowfalls on record, the UK, Republic of Ireland, Switzerland, France, Scandinavia, Germany, and Belgium were among those affected. Russia, eastern Europe and the USA did not escape. But while worldwide, billions were lost through traffic chaos, closed airports and reduced output with people unable to get to work, without winter maintenance the situation would have been much worse.Indeed in the UK, the
However, the organisation says: "Good winter maintenance is rarely noticed: only when things go wrong does it become a public issue.
"When sudden bouts of cold weather bring traffic chaos, icy roads receive high-profile coverage in the media and local authorities are criticised, often unfairly, for not affording greater protection."
With a membership of well-known companies, HTMA says it is committed to optimising winter maintenance practices in order to protect the environment.
The same is so in other countries including the USA and Canada, where maintaining highways is also expensive, particularly in the winter. Billions of dollars are spent annually by state and local agencies on snow and ice control operations, including the application of road salts.
Resources spent on winter maintenance, coupled with concerns about corrosion, environmental impacts and traffic safety, have prompted transportation agencies to explore more efficient strategies for snow and ice control.
One system that has found favour among many states is the use of a Maintenance Decision Support System (MDSS).
The
"In an effort to mitigate the challenges associated with winter maintenance decisions, the
The MDSS is a tool that merges weather forecasting with roadway maintenance rules of practice and generates treatment recommendations on a route by route basis.
"Although NCAR/RAL has been the lead laboratory in terms of MDSS development, several national laboratories have contributed considerably during the life cycle of the system, including the
Meanwhile,
"It adds new functionality and combines Vaisala's existing winter road maintenance products into one solution, enabling collection, quality control and archiving of data; customised forecasting, and display of information collected from various sources, such as road weather stations, radars and satellites," says the company.
The new interface, developed following extensive consultation with road engineers, makes the most of the latest web technologies to improve access to information, and it enables a high level of customisation for the users.
Vaisala's RoadDSS offers a number of interface levels so that users can choose the service most closely suited to their operations.
The primary aim of the Vaisala RoadDSS is to focus on the decision-making process. Each step provides all facts for the user.
The service includes the latest versions of two existing products: Vaisala Road Weather Observer and Road Weather Navigator 2.0.
Antero Jarvinen, director of the roads market segment at Vaisala explains: "A key challenge facing road maintenance engineers today is data overload. To ensure sound decisions, several parameters need to be considered. This, however, impacts the timeliness of the decision-making process. The new service reflects customer demand and will allow us to offer a one-stop solution for weather sensing, analysis, forecasting, display and post-event analysis, and facilitate quick and correct decision-making." Colorado Department of Transportation (CDOT), which uses MDSS, says that for winter it utilises a variety of products and techniques for the most effective treatment of snow, slush, ice and black ice on its state roadways, including sand, a sand/salt mixture, and various liquid anti-icers and de-icers. The type of storm and temperatures will dictate the products used.
"There are numerous benefits to using liquid anti-icer and de-icer techniques.
Advantages of these solutions on roadways at higher elevations include reduction in the use of salt and sand mixtures and improvement of road conditions during storms beyond what is possible by the use of sand and salt mixtures alone. "Since CDOT began using these products, it has reduced the consumption of sand used for winter road treatment in Colorado by up to 50%.
"Since increasing use of liquid anti-icing and de-icing products, there has been a significant reduction in the number of days that state highways are closed due to inclement weather," says CDOT.
The HTMA also points to the various materials used for 'gritting' UK roads including rock salt, which works by lowering the temperature at which water freezes, and prewetted salt, which reduces salt usage by about 25%; can be spread more evenly in the target areas, and can be applied at a faster application rate with a more immediate anti-icing effect.
An innovation is rock salt treated with agricultural by-products or molasses, which although slightly more expensive, is more widely being used. Manufacturers claim that 30% more material ends up on the road surface.
There are a number of other alternative anti-icers that are effective in preventing ice forming on carriageways including Urea and Konsin, acetate and ethylene glycol, but these are less widely used - being more expensive than rock salt; difficult to store, and requiring expensive plant.
Arlanda action plan
In December 2010, some of the largest airports in Europe were forced to cancel hundreds of flights because of the heavy snowfall.
At Stockholm's Arlanda Airport in Sweden a team of 130 people tackled snow and ice to keep the airport moving: the airport, operating since 1962, has never closed due to bad weather.A special fleet of
Arlanda has among the world's largest snow blowers, powered by Volvo, and the fleet of 17 Volvo A25D articulated haulers, nine wheel loaders of various Volvo models and a number of Volvo trucks, is fitted with special snow accessories.
The Volvo A25Ds have 7.3m wide ploughs to shovel snow from the tarmac, followed by a brush that sweeps away snow and ice and a blower, which blows away any remaining snow. By driving nine A25Ds alongside each other, it is possible to clear a 3.3km long, 45m wide runway in less than 10 minutes.
"This makes us the world's fastest airport snow-plough team," said Stefan Sundkvist, field coordinator at Arlanda Airport.
"We have a total of 250,000m² to clear, but aircraft have to continue taking off and landing at the same time. All the traffic has to be controlled and planned."
Kramer says that wheel loaders are primarily used to clear streets and parking areas as quickly as possible and to ensure that link roads also remain free of snow.
Its machines have two attachment points and a line-up of attachments, and can be deployed as a single snow blower or a combined snow plough and salt spreader, for example.
Kramer says it also offers features supporting a range of attachments, including auxiliary hydraulics, low-speed control, unpressurised return flow, manual throttle, load stabiliser and float positioning.
Meanwhile,
Intended for spreading salt, sand and deicing materials on roads, driveways, parking areas and recreational paths, the machine comes with a receiver hitch mount, and optional mounting kits include a utility mount and three-point mount for tractors. Spread width is variable from 1.2-12m, and the unit is designed to carry up to 158.7kg of salt, sand or de-icing material.
The Mini Pro 575 is recommended for use with utility vehicles, compact pick-ups, sport utility vehicles, pick-up trucks, small to mid-size tractors and skid steer loaders, says SnowEx, a product division of TrynEx International.
