Tow Plow Trailer Product

Overview

A tow plow is a simple, single-axle trailer that trails behind a pickup truck, using the truck's steering input to automatically angle a rear-mounted moldboard. Unlike traditional truck-mounted plows that require separate hydraulic controls, the tow plow integrates steering and plowing into one motion: when the driver turns the steering wheel, the trailer's steerable axle angles the blade left or right automatically, throwing snow in the direction of travel.

The design is economical and leverages the truck's engine and transmission. The truck provides hydraulic pressure via its PTO shaft; the trailer contains a proportional valve that reads the tow vehicle's steering signal and meters flow to the steering cylinders. A single operator clears secondary roads efficiently, and the optional Optional Salt Spreader applies de-icing material in one pass.

Trailer frame and chassis

The Trailer Frame is a simple welded-steel platform. The Frame Rails run the length of the trailer, with cross-members every meter for rigidity. The Hitch Tongue receiver extends forward and accepts a standard 2 inch ball coupler from the pickup truck hitch. The Axle Mount subframe carries the rear steerable axle and isolation bushings that dampen vibration.

The Frame Gussets gussets are critical: as the plow blade cuts, it transmits reaction forces (called draft force) along the moldboard. Without frame rigidity, the trailer twists and the blade angle drifts. Modern designs use welded diagonals and box-section reinforcement to keep frame deflection under 5 mm even under heavy cutting loads.

Plow blade and pivot

The Plow Blade Assembly is the simple working end. The Cutting Edge is a hardened-steel bar bolted to the Moldboard Plate. The blade pivots at the Blade Pivot — a large-diameter king pin mounted at the trailer centerline. As the trailer's steerable axle articulates, it pushes or pulls the blade, rotating it left or right around this pivot.

The Return Spring are heavy coil springs (two sets, one on each side) that center the blade when steering input is neutral. If the driver turns the wheel sharply and then releases it, the springs push the blade back to center, tracking the trailer's path. This automatic centering is the key advantage: the driver doesn't need to manage plow angle, only steer the truck.

The blade itself is passive — no hydraulic cylinders actuate it. The force comes from the steerable axle pushing the blade via the frame linkage. This reduces complexity and cost compared to truck-mounted plows with separate blade angle cylinders.

Steerable rear axle

The Steerable Rear Axle System is the mechanical heart. The Axle Beam is a heavy forged axle capable of articulating ±25–30° from center. Twin Steering Cylinder extend and retract, pushing the axle beam left or right. The Steering Sensor (a simple pressure transducer in the proportional valve) signals the axle angle back to the valve, allowing proportional control — small steering input = small axle angle = gradual blade rotation.

The Tie Rods connect the steering cylinders to the axle steering arms. When the proportional valve opens the left spool, pressure is sent to the left cylinder, extending it and pushing the left end of the axle rearward, angling the rear left. The blade follows, rotating left, throwing snow to the right.

This configuration is called a "steerable-axle" plow. It has the advantage of being trailer-based (no truck modifications needed except PTO plumbing) but the disadvantage of being less responsive to fine steering inputs compared to truck-mounted plows with proportional blade cylinders. However, for secondary roads and non-critical routes, the simplicity and cost savings are worth the trade-off.

Hydraulic system and controls

The Hydraulic Drive and Control is fed by the tow truck's engine PTO. A Hydraulic Pump on the tow vehicle spins at engine speed, delivering 30–50 L/min at 210 bar. This flow is routed through Hose Bundle to the trailer.

The Proportional Valve is the key control element. It receives an input signal from the tow truck's steering column — typically a linear position transducer (LVDT) mounted on the steering shaft that outputs a 0–5 V signal proportional to wheel angle. The proportional valve's spool is controlled by this voltage input. More voltage (more steering wheel turn) = more spool opening = more flow to the axle steering cylinders = sharper blade angle.

A Fluid Tank on the trailer holds return flow from the cylinders and provides a small surge capacity for transient flow spikes. The Relief Valve protects against overpressure if the axle hits an obstacle and stalls. Typically set at 250 bar, it vents excess flow back to tank.

The hydraulic feed hoses use flat-face Hydraulic Couplers quick-disconnects, making attachment to the truck literally a 30-second job: reverse the truck close to the trailer, mate the couplers, and you're ready to plow.

Electrical and lighting

The LED Markers and Warning Lights are simple LED marker and strobe units powered by the tow truck's 12 V system via a sealed Electrical Connector (typically a 7-pin round connector). The marker lights are amber at the trailer corners; strobes are red or amber on the roof, flashing to alert oncoming drivers that the plow is deployed.

Some modern installations include brake and turn-signal lights on the trailer as well, though older tow-plow designs may omit these if the tow truck's lights are sufficient.

Quick coupling and hitch

The Hitch and Quick Couplers is standard. The Ball Coupler accepts the pickup truck's ball (2 inch Class 2 is typical), and the Safety Chains provide backup restraint. The whole system can be coupled and decoupled in 2–3 minutes: back up to the trailer, insert the ball coupler, tighten the coupler lock nut, connect the hydraulic and electrical connectors, and check that guy chains or safety chains are secure.

Optional salt spreader

Many tow-plow customers add a Optional Salt Spreader to the trailer for single-pass de-icing. The Spreader Hopper (100–200 L) sits on the trailer frame above the deck. The Spreader Auger is a small screw conveyor driven by a 2–3 kW electric motor powered from the tow truck's 12 V or alternator-supplied circuit. A Spreader Gate gravity-fed metering valve throttles salt into the auger at a fixed rate (no electronic speed control).

The salt is carried back along the auger to a Spreader Disc, a simple spinner that throws it across the plowed area. Application rate is set by the gate opening and auger motor speed; in operation, the driver must slow down if more salt is needed, speed up if less.

This combination (plow + spreader) is highly efficient for secondary roads: the truck clears the snow mechanically, and the spreader applies salt for anti-icing in a single pass at 5–10 km/h. Repeated passes are unnecessary.

Typical operation

A pickup truck equipped with a tow plow and spreader is assigned a 50 km network of secondary roads and parking lots. The driver travels slowly (5–15 km/h), steering the truck naturally — as the driver turns left, the trailer's steerable axle automatically angles left, and the blade throws snow to the right. On the return pass, the driver turns right, and the blade angles right, throwing snow to the opposite shoulder.

The proportional steering link keeps the blade angle proportional to steering wheel angle: small turns produce small blade angles; sharp turns angle the blade more aggressively. With practice, drivers learn to anticipate blade response and make smooth, flowing passes without hesitation.

The spreader runs continuously at a fixed rate, applying salt based on hopper size and gate opening. For light conditions, the driver might set the gate to 25% open; for heavy ice, 75% open. The truck can clear and salt an average parking lot (5000 m²) in 30–45 minutes.

At the end of the shift, the operator backs the truck to the trailer coupler area, reverses into the ball receiver, and connects hydraulics and electrical. The trailer is then towed to the next site or back to the maintenance yard for refill.