Screw clamps. Screw clamps are types which use a screw mechanism to adjust the jaws and clamp a workpiece in place. The types which are found in the screw clamp category include G clamps (also known as C clamps), F clamps, edging clamps, wooden hand screw clamps and rack clamps.
Dry drowning usually happens soon after exiting the water, but with secondary drowning, there can be a delay of up to 24 hours before the person shows signs of distress. Both can cause trouble breathing and, in worst-case scenarios, death.
There are two primary theories as to what causes dry drowning, and it may well be that both are correct and that this form of death can be brought on in two different ways. The first theory is that a sudden rush of water into the throat causes the airway to snap shut, a condition known as a laryngospasm.