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By Daniel P. Bearth, Senior Features Writer
This story appears in the April 16 print edition of Transport Topics. Click here to subscribe today.
What cigarettes are to smokers, corrosion is to highway trailers.
That’s the analogy Phil Pierce likes to use to explain why as many as 90% of dry van trailers used by carriers his company surveyed last year are being scrapped after seven to 10 years of service because corrosion in steel cross-members, door frames and coupling devices has rendered the trailers unusable.
The problem is “a lot bigger than people want to believe,” said Pierce, president of PRP Industries in Muskegon, Mich., a company that markets an anti-corrosion metal treatment.
“It may seem odd to compare corrosion to smoking, but it’s actually a very accurate analogy. Smoking is the leading preventable cause of death among adults,” Pierce said. “Corrosion is the leading preventable cause of trailer death. It’s the tobacco of the industry.”
Glen Merkel, president of Davis Cartage Co. in Corunna, Mich., said his company has been forced to sell or scrap dozens of trailers after five to seven years of use because of “severe corrosion” of upper coupler assemblies and cross-members.
“Our philosophy is to keep trailers 14 years,” Merkel said. “The technology is out there to offer equipment with better corrosion protection, but it’s not currently offered.”
Virtually all trailer makers contacted by Transport Topics said they were taking steps to protect against corrosion by substituting noncorrosive materials, such as galvanized and stainless steel, applying rust inhibitors to the undercarriage and using trailer components with improved protective coatings.
“We’re doing a lot of little things in design,” said Bill Wahlin, vice president of engineering for Stoughton Trailers, Stoughton, Wis. “We’re welding some joints that don’t need to be to keep water and road salt out of crevices. We’re constantly evaluating new coatings.”
Hyundai Translead, which manufactures trailers in Mexico, began using a hot-dip galvanizing process for its whole trailer assemblies about four years ago, said�� Howard Yurgevich, the firm’s vice president of research and development.
The exposed upper coupler assembly is painted, although buyers can specify a stainless steel option, he said.
Yurgevich said the changes have been made without raising the price for the customer. The industry may want all other things, he said, "but are they willing to spend the money?”
Craig Bennett, senior vice president of sales and marketing for Utility Trailer Manufacturing Co., City of Industry, Calif., said the company completed a corrosion upgrade on its refrigerated van trailers about 10 years ago and believes it is still doing a good job at stopping corrosion.
“We made the box tighter, so chemicals don’t get inside. For the underside and exterior parts, we went to a wax-based coating that has proven to work extraordinarily well.”
Kingpin and upper coupler assemblies, which are dipped in a 400-degree wax bath to coat internal and external parts, show no signs of corrosion after 12 years in service, Bennett said.
Lynn Reinbolt, president of Road Systems Inc., a trailer manufacturing division of trucking and logistics service provider Con-way Inc., said his company has been able to increase the projected life of its dry van trailers to as long as 20 years. This endurance has been accomplished through a combination of new designs, the substitution of plastics and stainless steel and the use of rust inhibitors and metal treatment processes, he said.
“The number one reason that trailers don’t last that long is corrosion,” Reinbolt said.
Despite the claims of trailer makers, fleet operators say manufacturers aren’t doing enough to help with corrosion issues.
“Fleets generally expect dry van trailers to last 10 to 15 years, depending on the application and the maintenance cost they are willing to pay to keep them road-worthy,” said John Sullivan and Jerry Thrift, in a joint statement to TT.
Sullivan is chairman of a corrosion task force for the Technology & Maintenance Council of American Trucking Associations. Thrift is senior manager, maintenance, for Ryder System Inc.
A survey of 50 fleet maintenance mangers in 2004 by TMC found that 87% had premature failure of a component and 63% had a road call because of corrosion. Nearly nine out of 10 managers surveyed said they would be willing to pay more for corrosion protection.
Corrosion has existed since motor vehicles began hauling freight, but the problem got much worse in the mid-1990s when state highway officials began using new combinations of chemicals and salt to prevent ice and snow buildup on roadways.
Almost immediately, trucking companies began seeing signs of corrosion on relatively new trailers and on component parts, such as electrical connectors and brakes.
More than 2.6 million tons of salt and nearly 10 million gallons of liquid de-icer are applied to U.S. roads every year, according to a study conducted for ATA by Douglas Moore, director of the Technology Transfer Center at the University of Idaho in Moscow, Idaho.
Moore estimated it costs the U.S. transportation industry $23 billion annually to repair and replace corrosion-damaged equipment.
Another study by the Government Accountability Office in 2006 put the bill for corrosion damage on equipment used by the U.S. Army and U.S. Marine Corps at between $10 billion and $20 billion a year.
To minimize the effect of corrosion, the GAO recommended that the Army examine the feasibility of temporary shelters to protect assets currently stored outdoors.
The broadest study ever done of corrosion was completed in 2002 by NACE International, a Houston-based organization that represents engineers who specialize in corrosion prevention. That study, which has not been updated, put the total direct cost of corrosion in the transportation sectors at $29.7 billion a year, with $23.4 billion attributed to motor vehicles.
“Corrosion can be controlled but at a cost,” the report’s authors stated in a summary of findings.
Motor vehicle costs included $14.45 billion in depreciation, $6.45 billion in repairs and maintenance and $2.56 billion in increased manufacturing costs.
The most commonly used methods to control corrosion are coatings, alloys and plastic materials and polymers, and cathodic processes that use electric current to protect pipelines.
“Corrosion is so prevalent and takes so many forms that its occurrence and associated costs cannot be eliminated completely,” the NACE report said. “However, it has been estimated that 25% to 30% of annual corrosion costs in the U.S. could be saved if optimum corrosion management practices were employed.”
So what is being done?
Vic Suski, an engineering consultant who recently completed a study of the cost of corrosion for ATA, said the first job is to convince state highway departments to use less-corrosive chemicals on the highways.
Chloride-based chemicals mixed with corn or cane-based liquids are less corrosive, and some additives may actually protect metals against corrosion. Calcium magnesium acetate and potassium acetate are considered safe for vegetation, groundwater and concrete. “It is less corrosive than distilled water,” Suski said.
Though some states have tried the new less-corrosive formulations, cost is a major roadblock to widespread use.
Suski said road salt costs about $30 a ton, but products using a corrosion inhibitor cost about $100 a ton and CMA costs $200 a ton.
“Washing is the only option offered to fleets,” Suski said.
Meanwhile, equipment manufacturers, have been forced to re-design their products.
Engineers at Phillips Industries, a manufacturer of electrical components in Santa Fe Springs, Calif., came up with a new waterproof design for the seven-pin connector that carries electrical power from the tractor to the trailer.
“We found a way to isolate the connectors and not allow moisture or chemicals to migrate into the electrical system,” said John Jacobs, vice president.
Since Phillips offered the new design about three years ago, warranty claims have fallen by 20% to 25%, Jacobs said.
Despite that success, he said, more research needs to be done to make de-icing compounds less damaging to the large amount of copper and brass in truck and trailer wiring systems.
Keeping electrical connectors free of corrosion also requires some extra attention to maintenance.
“We recommend frequent washing and greasing the contacts,” Jacobs said.
Another priority for truck operators and component manufacturers is stopping an increase in corrosion on brake parts.
Longhaul truck fleets, in particular, have experienced an increase in what is called “rust jacking,” or the buildup of corrosion between the brake shoe and lining, causing the lining to crack, according to researchers at Oak Ridge National Laboratory, Oak Ridge, Tenn.
The frequency of this type of brake failure has doubled since the adoption of new road-clearing chemical mixtures, said Philip Sklad, a project manager at Oak Ridge who published a study on the problem in 2005.
The study found that longhaul trucks were exposed to a wide variety of de-icing and anti-icing compounds in various concentrations and order of exposure.
“While brake failure is reported to have increased,” Sklad said, “it is unclear how the new exposure factors contribute to the failure mode and rate.”
Another expert who has studied the effect of de-icing agents on truck equipment is Patricia Olsgard, director of safety for the Colorado Motor Carriers Association. She said road salts and chemicals do more than corrode brake components. The spray coats windshields and lights; shorts out wiring and electrical connectors; pits hoses, belts and tires; and attracts moisture from the air, making road surfaces slippery long after the snow and ice have been removed.
SAF Holland, a manufacturer of trailer fifth wheels and suspension products, said it applies a coating to its landing gear to prevent corrosion. The substance, called Black Armour, reacts to any metal that oxidizes, is impervious to water and remains intact when struck or if the surface is scratched or bent.
The primary focus of trailer manufacturers continues to be the use of galvanized steel and aluminum to replace carbon steel on their products.
“We use a lot of galvanized product for the rear frame, the understructure, down to the mud flaps,” said Bob Taylor, director of trailer sales for Vanguard National Trailer Corp., Monon, Ind.
A 4-foot section of galvanized steel is installed beneath the trailer coupling device to deflect road debris and keep road spray from seeping into the trailer floor, Taylor said.
In March, Great Dane Trailers, Savannah, Ga., introduced a new package of corrosion prevention features, including CorroGuard, a thermoplastic elastomer coating applied to suspensions and support gear.
CorroGuard is airtight and watertight and will not crack, warp, flake or split under the harshest of conditions, said Rick Mullininx, Great Dane’s vice president of engineering.
The company’s standard offering was an undercoating for steel components and an epoxy primer-urethane combination for rear door frames and platform trailers.
“We’ll never be able to do enough,” said Stoughton’s Wahlin. “The new road salts are a little more difficult to wash off. They adhere to surfaces to the point where a pressure wash isn’t enough. To really get it clean, you need to wipe it down.”
Because it’s not practical to physically wipe down the undercarriage of trailers after every wash, Wahlin said, he recommends that fleets reapply some kind of wax-based protective coating about every seven years.
Another issue for trailer makers tackling corrosion, Wahlin said, is the fact that prices for zinc and nickel used to make galvanized and stainless steel and some coatings are rising rapidly.
Wahlin said most trailer makers also are looking at a variety of coatings and liners to protect trailer components.
“There is a lot of testing,” he said. “The difficulty is the cost.”
Rod Ehrlich, chief technology officer at Wabash National Corp., Lafayette, Ind., said his company is replacing all incandescent lights with water-resistant LED lamps, has designed sealed components for brakes and landing gear and has replaced plywood in its swing doors.
Wabash is evaluating several types of metal coatings to protect the undercarriage, Ehrlich said.
“You have to be careful,” he said, “because something that is very corrosive-resistant, if damaged, can actually accelerate the process of corrosion.”
Use of high-pressure washing equipment also can have an effect on trailer corrosion, Ehrlich said.
“A strong cleaning solution that is blasted into some parts of the trailer, you will not get out and it becomes a vessel for a very corrosive material,” he said.
“Wash it often, but water and a little elbow grease works best,” he added.