Gate systems for vehicles can trap and possibly injure persons in areas called entrapment zones. These zones occur when the gate is moving to an open or closed position. The location of the entrapment areas depends on the design of the gate system.
Some possible areas where entrapment may occur:
- Where a gate opens toward a fixed object, such as a wall or fence;
- Where two edges of a swing gate meet as they close.
To prevent this type of accident from occurring, it’s important to inspect protection devices regularly, to ensure they are in good working order. Underwriter’s Laboratory, the national testing agency, has an extensive set of rules that cover these vehicular (and other types) of opening and closing gate systems, called UL-325. Owners of property that use gate systems should be familiar with these rules, and also discuss with legal counsel the liability issues that might involve a vehicle gate system.
While the rules are too extensive to go into detail in this blog, these are the four classes of gate operators:
- Residential (single to four homes, garage or parking areas)
- Commercial or general access (five or more homes, general public access)
- Industrial/limited access, such as for factories, loading docks, etc.
- Restricted (guarded locations)
These classifications will have separate standards, depending on the type of gate, such as horizontal slide, vertical lift or vertical pivot; or, vertical barriers or swing gates.
Code requires a primary device as well as a backup device for each entrapment area and category. Among the devices that might be installed:
- Pressure devices
- Adjustable clutch devices
- Audio devices
- Photo-electric devices
- Edge sensors
Note that the same type of device may not be installed for primary and secondary protection.
The standards also require monthly testing of operators, as well as maintenance that adheres to the manufacturer’s recommendations. It’s a good idea to leave inspections and testing to qualified pros.
Here’s a video from LiftMaster that illustrates entrapment zones with different types of gates, and the kind of safety equipment that U-325 calls for. In fact, Liftmaster offers several videos that might be helpful for those with properties employing a gated entry, including one for checking safety performance on swing- and slide-gate installations.