Karabiners are a little thing that make a world of difference.
Below is a breakdown of the four most common karabiners for height safety:
Single Acting Non-Locking – Least secure, but does provide a fast, hassle free connection
Double Action Self Locking – Relatively secure with a quick connection but requires two hands to insert a device. In some circumstances the rubbing of a rope on equipment can unlock the gate so vigilance is required
Manual Locking Screw Gate – Relatively secure when locked by the worker, but requires constant attention to make sure it doesn’t unlock itself. Screw gates are more reliable in dirty or harsh environments in comparison to their self locking counterparts
Triple Action Self Locking – Most secure, but take longer to connect as the sleeve needs to be locked and unlocked each time the gate is opened. Two hands are required to connect a device. Self locking feature can become defective in the presence of dirt or other foreign materials
When selecting a karabiner, always make sure it is rated for height safety. Even if a karabiner is self locking it always needs to be checked before, during and after use.