Another trailer peeve;
The trailers all have an emergency brake, it is a spring-loaded lever similar to the one in a package car. You connect it to the bumper of the tow vehicle with a "breakaway" cable, so that if the trailer seperates from the tow vehicle the cable will pull on the brake lever and activate the brake.
The geometry of this brake lever is such that the rubber sheath that encloses the brake cable has its open end facing upward. Whenever it rains, or the trailer is washed, a small amount of water will run down into the cable sheath and collect at the lowest point in the line, which is underneath the trailer half way back to the wheels.
When the trailer is parked at night, the brake is set to keep it from rolling. In the winter when the temp gets below about 25 degrees, that water will freeze and bind the cable up in the sheath. When you try to deactivate the brake, the cable will kink because it cannot move. It is basically like trying to push a piece of string thru a drinking straw full of ice. Once this happens, the trailer is immobilized and the only way to move it is to take a torch to the cable housing to melt the ice (illegal if the trailer is loaded) or to crawl under the trailer and disconnect the emergency brake completely (illegal to drive in such a condition). Neither "solution" is acceptable; if you melt the ice it will just freeze up again the following night, and if you disconnect the cable you are defeating the entire purpose of having an emergency brake in the first place.
I have been complaining to EVERYBODY (automotive, center team, safety committee) about this for the last 15 years, and no effective solution has been found. Last winter they tried injecting antifreeze into the sheath with a syringe. Didnt work. One morning we had at least 8 trailers frozen in place and unable to move. Major dispatch headaches, yet it happens over and over again every winter.
My solution is simple; I do NOT set the brake when I park at night, instead I secure the trailer with some wheel chocks that I stole from Automotive. To keep carwash or preload from forgetting and setting the brake on accident, I padlock it in the "off" position until I am ready to hook it up and leave with it. The brake will still deploy if the trailer seperates, because you are "pullling" the cable thru the frozen sheath instead of trying to "push" it.
Apparently my simple and cheap solution is still too complicated and expensive, because the company feels that it is more cost-effective to pay a mechanic to crawl under the trailer and try to repair the the problem in the morning while the driver waits and the packages miss service.