A method of supporting a trailer using a portable trailer stabilizer, the method comprising: (i) contacting a trailer engagement element of a portable trailer stabilizer with a forward end portion of a parked trailer using a tractor coupled to the portable trailer stabilizer; (ii) compressing a hydraulic cylinder containing pressurized hydraulic fluid and directing the pressurized hydraulic fluid to a hydraulic accumulator via an open isolation valve by pressing the trailer engagement element against the forward end portion of the parked trailer to compress the hydraulic cylinder to move the trailer engagement element from the fully extended configuration to a partially extended configuration by positioning the portable trailer stabilizer at least partially beneath and the forward end portion of the parked trailer using the tractor, the hydraulic cylinder operatively coupled to extend the trailer engagement element relative to a support surface engagement element, the isolation valve fluidically interposing the hydraulic cylinder and the hydraulic accumulator; (iii) extending the hydraulic cylinder while maintaining contact between the trailer engagement element and the forward end portion of the parked trailer by lowering the support surface engagement element to engage a support surface beneath the trailer; and (iv) shutting the isolation valve and securing the trailer engagement element against the forward end portion of the trailer by disengaging the tractor from the portable trailer stabilizer, shutting the isolation valve preventing compression of the hydraulic cylinder, where disengaging the tractor from the portable trailer stabilizer actuates a valve operator mechanism operatively coupled to the isolation valve, the valve operator mechanism being operative to open the isolation valve when the portable trailer stabilizer is coupled to the tractor and to shut the isolation valve when the portable trailer stabilizer is uncoupled from the tractor, and where the hydraulic cylinder, the hydraulic accumulator, and the isolation valve are operatively connected in a closed hydraulic system.

A portable trailer stabilizer includes a support surface engagement element, a trailer engagement element, a hydraulic cylinder that extends the trailer engagement element relative to the support surface engagement element, an on-board, self-contained energy source including a hydraulic accumulator for the hydraulic cylinder, an isolation valve fluidically interposing the hydraulic cylinder and the hydraulic accumulator, a positioning element engagement element to selectively couple with a trailer stabilizer positioning element of a tractor, and a valve operator mechanism to (i) open the isolation valve when the positioning element engagement element is coupled to the trailer stabilizer positioning element of the tractor, and (ii) shut the isolation valve when the positioning element engagement element is uncoupled from the trailer stabilizer positioning element of the tractor. The hydraulic cylinder, the hydraulic accumulator, and the isolation valve are operatively connected in a closed hydraulic system containing a hydraulic fluid.

Devices are for compensating for the roll of a fifth-wheel coupling, such as on a prime mover towing a semi-trailer. An automated compensation system for a fifth-wheel coupling mounted on a towing vehicle unit includes a first pivoting support to support one lateral side of the fifth-wheel coupling; a second pivoting support to support an opposite lateral side of the fifth-wheel coupling; an actuator configured to cause movement of the first and second pivoting supports; a sensor to sense a parameter relevant to determining whether roll compensation is required for the vehicle; a controller configured to receive a sensor output of the sensor and to determine whether roll compensation is required based on the sensor output, the controller being further configured to issue a control signal to cause the actuator to move the first and second pivoting supports when the controller determines that roll compensation is required.

An embodiment of a connector for a fifth wheel system of a tractor-trailer includes a stinger, a kingpin, a material support, and a trailer hitch. The stinger has a length extending from a first end to a second end. The kingpin is positioned at the first end of the stinger. The trailer hitch is positioned at the second end of the stinger. The material support is position above the kingpin and is rotatable with respect to the kingpin about a vertical axis of rotation. An embodiment of a trailer may be connected to both the kingpin and the trailer hitch, and material is loaded upon the material support.

A method of stabilizing a trailer includes driving a tractor, operatively coupled to a portable trailer stabilizer, forward to position the portable trailer stabilizer at least partially beneath a forward end portion of a trailer that is parked; operatively decoupling the portable trailer stabilizer from the tractor to retain the portable trailer stabilizer at least partially beneath the forward end portion of the trailer that is parked; and driving the tractor, operatively decoupled from portable trailer stabilizer, rearward to vacate a position immediately in front of the forward end portion of the trailer while parked.