Power Only
A dispatch arrangement where a carrier supplies only the tractor to pull a shipper- or broker-owned trailer.
Power Only in Practice
No Trailer Ownership Costs
Power only carriers skip the purchase price, insurance, maintenance, and depreciation of owning a trailer entirely, which can meaningfully lower the capital needed to run an operation, especially for a new owner-operator.
Inspect the Trailer You're Hooking To
Since the trailer belongs to someone else, its maintenance history and condition aren't in the carrier's control. A pre-trip inspection of tires, lights, and brakes on an unfamiliar trailer is essential before pulling it any distance.
Clarify Trailer Interchange Terms
Power only arrangements often involve a trailer interchange agreement specifying who's liable for damage to the trailer while it's in the carrier's possession. Reading those terms before accepting the load avoids surprises later.
Power Only: What It Means and Why It Matters
Power only loads let a carrier generate revenue from the tractor alone, without owning or maintaining a trailer, which appeals to owner-operators who want to skip the cost and hassle of trailer ownership. It shifts the equation in meaningful ways though: trailer condition, detention risk, and rate structure all work a little differently than a standard dry van or reefer load.
How Power Only Works
In a power only arrangement, a carrier supplies just the tractor, the power unit, to pull a trailer that the shipper or broker already owns or has staged. The carrier hooks to that trailer, hauls the load to its destination, and then either drops the trailer or continues under a similar arrangement for the next leg. It's common in intermodal drayage and with shippers or brokers who maintain their own trailer pools.
A Practical Example
A broker has a loaded trailer sitting at a distribution center and needs it moved 400 miles to a retail warehouse. Rather than requiring a carrier with matching dry van equipment, the broker posts a power only load. Any carrier with an available tractor and a valid trailer interchange agreement can bid on it, widening the pool of carriers who can take the load.
This also means the carrier isn't tying up their own trailer on that lane, freeing it up to run other freight elsewhere with a second driver or a separate load, which is part of why some fleets use power only strategically to keep tractors and trailers decoupled and both assets earning independently.
Why It Matters for Owner-Operators
Power only lowers the capital barrier to running freight since there's no trailer to purchase, insure, or maintain, which can make it attractive for an owner-operator watching cash flow closely. It does introduce risk in the form of unfamiliar equipment though. A trailer with a slow tire leak or a wiring issue the carrier didn't cause can still become the carrier's problem once it's hooked and moving, so understanding the interchange agreement's liability terms matters.
Common Misconceptions
A common misconception is that power only always pays less than hauling with an owned trailer, when in practice rates depend on the lane and the shipper, not the arrangement itself. Another mistake is skipping a full pre-trip inspection on a trailer that isn't the carrier's own, assuming it's someone else's responsibility, when in most interchange agreements the carrier is on the hook for its condition once it's hooked and rolling.
Related Calculators
Related Equipment Terms
Carriers on Power Only
“Power only let me start hauling without saving up for a trailer on top of the tractor. I just make sure to walk every trailer I hook to like it's my own.”
“I read the interchange agreement closely now after getting stuck with a repair bill on a trailer that wasn't even mine. That paperwork matters more than people think.”