Common sense suggests that if a trailer’s doors are open, its refrigeration unit ought to be shut down. But many customers disagree, thinking the products will be better protected if cooled air continues to circulate as freight is being unloaded.

This bothered Shelley Koch, president of K&J Trucking, Sioux Falls, S.D. She had observed that with doors open, fan-driven air flow inside the trailer pulls in warm air that actually hurts the product. Koch started using a doors-open/reefer-shutdown mode that’s an option on the fleet’s Carrier Transicold and Thermo King units, using door sensor-switches. But dock workers and indifferent drivers were getting around the switches and forcing reefers to run.

She needed to know when that was happening and had the right tool: Blue Tree Systems’ R:Com tracking devices that were installed on her 165 reefer units.

“We were spending a lot of time tracking the trailers and wanted to get something back in return,” Koch says. “There’s still a cost for the tracking, and I was hoping to defer that in monthly bills in fuel. The door switch is supposed to do that, but they can trick it with a magnet. Working with a programmer, we found that there’s a voltage change when they do that. But that’s sometimes hard to detect.”

However, data transmitted by the R:Com units tell dispatchers at K&J where their trailers and tractors are, and drivers report in when they’ve reached their destinations.

“If he’s arrived at his receiver and he’s opened the doors, and boom, the reefer starts up again, then we know something’s wrong,” she says. “We can contact the driver and tell him to shut it off. Orders are orders and he will, though some customers resist.” When that happens, Koch says, “we go back to the receivers and tell them there’s a problem and if it continues, there’ll be an extra charge. And that gets a lot of their attention.”

But “shippers have been awesome” about the procedures. “They see how this can benefit their products, especially with new food safety rules coming.”
Shutting down the reefers is easily paying the monthly tracking charge, which for K&J is $18 per unit.

Monthly charges vary with the number of units in a fleet agreement, as does the cost of an R:Com unit, says Chip Powell, Blue Tree’s director of U.S. operations.

Reefer tracking provides so much data that “it can be overwhelming,” says Koch, but especially valuable are records of en route product temperatures and yes, open doors, that can settle disputes with receivers. “So it’s saved us quite a bit of money and heartache.”