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Material handling/Safety
Key concepts
Restraints must address four types of trailer separation from the dock: trailer creep, unexpected departure, landing gear collapse, and trailer unending.
Selection criteria include constant engagement, clear communications, durability, and ease of maintenance.
Training of dock employees and visiting truck drivers is essential.
Vehicle restraint systems are a major factor in making the loading dock a safer workplace. However, it is dangerous to assume that the mere presence of the equipment erases the specter of a forklift and driver falling over the edge of the dock because a truck trailer shifts or pulls away unexpectedly. Actual safety gains result from carefully choosing the restraint system that best suits the operation, maximizing the investment by maintaining it, and training dock area employees to use the equipment properly.
A restraint that does not meet basic safety and operational criteria and provide full-time security is no longer a safety device, but an increased hazard, because a false sense of security exists. The same holds true for standard wheel chocks, which frequently go unused, and can also be ineffective against most types of trailer movement.
The consequence of even one restraint failure is often disastrous, including crippling or fatal injuries. Therefore, the device chosen must be reliable and effective under all operating conditions.
Operational considerations
There are two basic styles of mechanical trailer restraints:
Restraints that attach onto the rear impact guard, or ICC bar
Locks that secure the trailer's rear tires.
ICC-style restraints are more common; however, for lift gate trailers and other vehicles that lack an ICC bar, wheel-locking restraints offer an effective alternative.
Almost all ICC-bar restraints have two basic components: a device that holds the trailer to the dock, and a communications system of lights and signs that tell the forklift operators and truckers when the trailer is secured and when it is not. Dock employees typically activate and release the restraint system from a push-button panel located adjacent to the dock door.
Variations of the two common types are numerous. Restraints are available with a variety of barrier configurations and can be powered mechanically, pneumatically, or hydraulically.
Rotating hook style restraints have been around the longest, and represent the majority of units installed. Popularity of this restraint...