It's not enough to write the correct specs for trailer insulation values when you order. Proper maintenance and repairs are vital. The Technology & Maintenance Council of ATA has a task force on preserving reefer insulation values,
headed by Lori Coleman, Gordon Food Service. Members plan to write a TMC Recommended Practice on the subject.
Early on they identified a basic problem: When trailers are damaged, repairs too often don't get done, because there's always pressure from operations people to keep the trailer busy moving cargo. "Triage repairs" are the best the maintenance department can do, said one fleet manager during a meeting of the task force at TMC's recent annual meeting. Some rips and punctures in a trailer's inner or outer skins are ignored or simply patched up in a hurry.
Why is this a problem? Damage allows moisture to enter the walls, ceiling or floor and degrade the foam insulation. Water crushes the foam's bubbles and forms voids. Heat can then move easily between outside and inside the trailer, and the reefer unit has to work harder and use more fuel while trying to maintain the desired interior air temperature.
How much water can a reefer trailer absorb? Hundreds and even thousands of pounds, said Chuck Cole of Utility Trailer Manufacturing. He cited one example where 2,500 pounds of water had accumulated where insulation had been. The easiest method of determining water contamination is to weigh the trailer. Top off all fluids in the reefer unit, fill the fuel tank and park it on a scale. Of course, you have to know what it weighed when new, so scaling it the same way should be part of a delivery procedure. Failing that, the manufacturer should be able to provide an estimate of a trailer's as-built weight.
The most effective solution to timely repairs is regular inspections of reefer trailers and giving the maintenance department the ability to sideline it for enough time to repairs things right. "That's the ideal," said Coleman, a manager at Gordon's facility in Grand Rapids, Mich. "Then there's the real world."
Inspections should be part of regularly scheduled preventive maintenance visits. Repairs to forklift-inflicted tears and other damage to walls, floors, ceilings and doors must be done quickly but effectively, using good quality sealants. Use methods approved by trailer builders.
"Do what they say," advised Bud Rodowick, a former fleet manager who now represents Thermo King. "The information is available. Just ask 'em." Among other things, badly damaged panels should be pulled out and replaced, and insulation repacked. Hire third-party repair specialists if you can't do it yourself.
Water also gets in through seams between side sheeting and along roofs, Utility's Cole noted. There are 400 to 500 linear feet of seams along the sides and top of a typical 53-foot reefer trailer. Age and road vibration cause caulking to dry and shrink and the seams to gradually open. These should be recaulked and repaired where necessary.
Doors, particularly the relative merits of swing versus rollups, occupied about 10 minutes of the task force members' time. Most agreed that gaskets on swing doors did a superior job of sealing in cooled air. Rollups, while convenient in some operations, cannot press hard enough against their brush-type seals to keep out summer heat or winter cold. No matter which type of door is in use, inspect them regularly for damage and deterioration and do repairs promptly.
One remedy for a weak rollup door seal is to place a movable bulkhead against the rear of the load, Coleman said. But that takes up valuable floor space.
Floors are another problem area. They can leak like sieves and you won't know it unless you look at them closely, said Cole. Crawl under the trailer and look up and you might see points of light from the interior lamps. Or look down from inside a dark trailer and you might see daylight. Acidic cleaning solvents used for flushing out debris and sanitizing trailer interiors can etch aluminum floors and eventually form tiny holes. Cleaning must be done, but beware of potential damage.