Having grown up in Northern Idaho and Eastern Washington around heavy equipment, seeing a dump truck transfer was about as common as seeing an pickup with a rifle in the rear window during hunting season. Transfer units are also very popular in California, although you usually won’t see the rifle in the rear window there.
Whenever I travel, I take special notice of heavy equipment configurations in different areas of the country. I find it fascinating that different areas can use such different equipment configurations for the same type of job.
One configuration that seems to be a rarity on the East Coast is a dump truck with a transfer trailer. For anyone unfamiliar with this set up, it’s a standard dump truck pulling a trailer with a dump box (Box “B”). Box “B” is powered by an electric motor, pneumatic motor or hydraulic line. It rolls on small wheels, riding on rails from the trailer’s frame into the empty main dump box on the truck (Box “A”). Unlike a common pup trailer, it doesn’t have its own hydraulic ram, but instead utilizes the hydraulic ram of the dump truck when the trailer box is transferred into the truck box.
This maximizes payload capacity without sacrificing the maneuverability of the standard dump truck. Transfer dump trucks are typically seen in the Western United States. Some say it’s because of weight restrictions in the East, but since the total pounds per square inch in this configuration are still within the Federal Department of Transportation (DOT) guidelines, it could be that the DOT or local jurisdictions in the East are simply unfamiliar with the configuration.
The transfer unit has its pros and cons, as any truck configuration does. A truck pulling a pup trailer can dump its load faster, but generally the pup trailer will only haul 8 to 10 cubic yards of material, where a transfer trailer can haul 10 to 12 cubic yards. While a transfer trailer may not be as fast as a pup trailer, it has benefits other trailers don’t have, such as maneuverability. Because of the design of the transfer unit, a driver can easily maneuver them in tight spaces instead of having to abandon the trailer all together for jobs where it may not fit.
This is really the biggest reason why many companies use dump truck transfers. It allows them to haul almost two loads of material per trip and get each load into very confined spaces. With the high cost of fuel the more material you can move with less trips, the more profitable the job is. And anytime you can haul two loads while only making one trip, that’s maximizing your bottom line.