The Short Answer
A vehicle restraint is a safety device that mechanically locks onto a truck's ICC bar (rear impact guard) to stop the trailer from moving while it is being loaded or unloaded. A rotary hook engages the bar and holds it with up to 14,500 kg (32,000 lb) of restraining force, preventing the most dangerous loading dock accidents.
How It Prevents Accidents
Without a restraint, a trailer can creep forward from repeated forklift impact, the driver can pull away early, or the landing gear can collapse under load — all of which can injure workers or drop a forklift between the dock and the trailer. The rotary hook provides a positive mechanical lock on the ICC bar, so the trailer physically cannot move until the hook is released.
PLC Interlocking
The full safety benefit comes from interlocking the restraint with your dock leveler. With the REDA PLC control system, the dock leveler stays locked until the restraint is engaged, and the overhead door and dock shelter can be integrated too. Inside/outside LED lights (green = safe, red = stop) keep forklift drivers and truck drivers in sync. The control circuit runs on DC 24V safety voltage.
THM-800 vs THM-600
Both models hold the same 14,500 kg (32,000 lb) and use a forged 65Mn steel hook. The difference is ICC bar range and footprint.
| Model | ICC Bar Range | Best For |
|---|---|---|
| THM-800 | 230–762 mm (9–30 in) | Mixed fleets, high-volume docks |
| THM-600 | 254–610 mm (10–24 in) | Standardized fleets, tighter budget |