Thus it’s high time to examine some of the ongoing winter preparatory activities across the transportation spectrum.
Let’s start with the roads and let’s use the Virginia Department of Transportation (VDOT) in my home state as an example.
[Though the video below dates from 2008, it provides a nice overview of the agency’s overall winter weather strategy.]
VDOT Commissioner Charlie Kilpatrick noted recently that his agency prepares “year-round” for snow with a wide variety of resources:
- A $202.4 million “winter weather” budget;
- Some 2,500 VDOT crewmembers in addition to contractors available for snow removal statewide;
- A fleet of 13,173 pieces of snow-removal equipment, including trucks, loaders and motor graders;
- A supply of 657,162 tons of salt, sand and treated abrasives plus 1.7 million gallons of liquid calcium chloride and salt brine.
VDOT is also testing four new “wing plow” this year, with four trucks in the Staunton District fitted with the unique front-and-side-blade design that will allow each vehicle to cut a 21-foot path of snow with each pass, essentially doing the job of two traditional plows.
VDOT is also recycling “runoff” to generate more road-clearing brine solution as well.
“When VDOT loads salt onto snow-removal trucks on a paved area – called a ‘mixing pad’ – at its salt-storage facilities, the runoff is directed either to impermeable ponds or underground tanks, since the mixing pad is normally wet during the loading process due to water or snow,” Kilpatrick noted.
“To manage this runoff, we’re reusing some of this water from the ponds or tanks to produce brine, a solution of salt and water, to turn an environmental challenge – disposing of that runoff – into a supply opportunity,” he added.
Indeed, VDOT said it is relying more on brine as it can prevent frozen precipitation from bonding to pavement while also reducing the overall amount of salt used.
Brine is also more environmentally friendly than salt and VDOT noted that its Richmond used more than 193,000 gallons of brine last winter, most of which came from runoff processed from its holding ponds.
Of course, vehicles large and small – commercial and non-commercial – need to be prepped to handle Old Man Winter’s charms, so many OEMs nowadays factor such “charms” into their vehicle design process right from the start.
Take Ford Motor Co.’s climatic wind tunnel in Allen Park, MI, which tests the winter-readiness and reliability of all the automaker’s vehicles – from its cars on up through the F-150 pickup – in blizzard-like conditions.
This climatic wind tunnel allows Ford to take cold weather testing off the roads and conduct it inside, where engineers can replicate wintry conditions year-round. At the facility, Ford subjects its vehicles to “worst-case” winter scenarios so they are prepared to handle snowstorms.
Of course, winter in not the only climatic condition Ford’s engineers can simulate at this facility, as they can drop temperatures down to as low as minus 40 degrees Fahrenheit or crank them as high as 130 degrees Fahrenheit.
Back on the snow front, Ford said its climactic wind tunnel can generate hurricane-like wind speeds of up to 125 mph, blowing snow at the front of the vehicle to simulate a blizzard.
Since snow can choke a vehicle’s engine, Ford said its engineers continuously monitor air intake, also checking whether shift linkages freeze up, and where on the vehicle snow accumulates.
Besides a four-hour test in the climatic wind tunnel, Ford said all of its vehicles also undergo two days of snow-related testing in the Upper Peninsula of Michigan, near Sault Ste. Marie.
Where diesel-powered trucks are concerned, though, a few other winter-season pointers are in order.
For a broad list of winter preparedness tips, make sure to visit Ryder System’s Winter Preparedness Hub.
- Cooler ambient temperatures decrease engine efficiency and increase aerodynamic drag, with every 10 degree drop in Fahrenheit equating to a 2% increase in aerodynamic drag.
- Tires lose pressure as temperatures drop and rolling resistance increases, thus reducing fuel economy.
- Rain, snow and slush all increase tire rolling resistance as well, with cold water significantly cooling tires plus transmission and rear axle lubricants. This results in a 0.2 to 0.3 MPG loss as cited by the Society of Automotive Engineers (SAE) data.
- Headwinds/crosswinds impact MPG as well, with every 10 mph worth of wind equating to a 13% drop in MPG.
- Engine idle time increases in the winter months as drivers seek to stay warm, while poor driving conditions brought on by the cold and snow lead to decreased use of cruise control.
Then there are the age-old issues regarding winter’s impact on diesel fuel, Spence said. “Most winter fuel problems start with moisture in the fuel. It is critical to keep water out of storage tanks and out of the fuel tanks on the truck,” he explained.
When a truck is parked and allowed to “cold soak,” any water in the system will settle out of suspension and freeze in the lowest place in the system or component.
“In the case of the tank, the water will freeze on the bottom of the tank. In the case of the filter, the water will freeze in the bottom of the filter,” Spence said. “A low place in a fuel line will also allow water to settle out and freeze in the low area. All of these situations can cause a flow obstruction and stop the flow of fuel and prevent the engine from operating.”
Then there’s the problem of diesel fuel “waxing” or “gelling” in cold weather; a problem typically addressed by added chemical to the fuel to lower its “pour point,” he noted.
“At temperatures around 20 degrees Fahrenheit – or even higher in some cases – the paraffin wax molecules in No. 2 diesel fuel begin to adhere together and slow the flow of fuel,” Spence pointed out. “This is commonly known as fuel gelling.”
That wax “gel” cannot pass through the fuel filter media and will eventually clog the filter, stopping the flow of fuel and ultimately shutting down the engine, he emphasized.
“The use of a ‘pour point depressant’ chemically alters the ability of the wax molecules in diesel fuel to cling together and therefore allows the fuel to flow at lower temperatures, typically to below 0 degrees Fahrenheit,” Spence added.
Another truck component in need of “winterizing” is the air dryer.
According to Richard Nagel, director of marketing and customer solutions for Bendix Commercial Vehicle Systems, the complications of lower temperatures with truck air systems center less about the air itself and more on the moisture it contains.
“When the compressor draws in air, it also brings in that moisture, pumping both into the air dryer,” he said.
“If the moisture makes it past the air dryer, it can condense inside the air tanks and find its way into the rest of the braking system," Nagel stressed. "Moisture in the air system is a problem at any temperature, but in cold weather, the condensed water can freeze, increasing the chance of malfunctions in brakes and valves.”
Trapped water can also freeze and prevent valves from functioning properly, while the stress of freeze-and-thaw cycles creates additional strain on components and chemicals applied to roads can corrode the dryer’s purge valve, he noted.
Thus it can often makes sense to replace air dryer cartridges annually in the fall, especially in cold climates, or on vehicles that consume higher air volumes, such as those in vocational applications.
Bendix also recommends using an oil-coalescing cartridge – designed to remove oil from the air – as oil aerosols passed by the compressor can be particularly harmful to air systems, deteriorating seals and contributing to premature damage in a variety of other components.
A second simple step toward keeping the air system moisture-free in winter, Nagel pointed out, is manually draining the air tanks periodically, based on the truck’s air usage.
“Up to once a month for vehicles with high air demand or every three months for a typical line haul truck is recommended,” he emphasized. “If moisture hasn’t been removed by the dryer – whether due to contaminated desiccant, a malfunctioning purge valve, or a lack of purge air supply – manually draining it from the tanks is a fail-safe method of removing it from the system.”
Nagel stressed that an air dryer’s purge valve is especially susceptible to contamination in winter due to the abundance of water, chemical treatment, salt, and sand on many roads.
“On vehicles operating in conditions involving long-term exposure to cold or contaminants like road salts, annual purge valve replacement is good preventive maintenance that can be scheduled along with installation of a new dryer cartridge,” he explained.
If part of a vehicle’s air system does freeze, however, the “traditional fix” has been to add alcohol or similar de-icing solutions until the affected area clears – but Nagel emphatically advises against doing this.
“The term ‘alcohol’ covers a wide variety of chemicals, many of which can corrode the compounds used in brake system seals, or break down valve lubricants, causing leaks or valve malfunctions,” he stressed. “Even methanol, a commonly used alcohol in de-icing solutions, can cause long-term damage.”
If alcohol does get added to the air system, Nagel said it’s important to check for leaks around the brake valves if the O-rings were exposed to the anti-freeze compound. “Leaks can be audible, or they can be detected through the use of a soap spray,” he noted. “If a valve is leaking, either replace the O-ring with a new one, or replace the entire valve with a new or remanufactured component.”
Advice to keep in mind as winter starts closing its icy grip around us.