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.
A child doesn't have to be visibly struggling in the water for this to happen. All it takes is some unexpected water in his or her mouth or a playful dunk. Unlike the relatively quick timeline of dry drowning, secondary drowning can occur up to 24 hours after a child leaves the water and involves water in the lungs. When a small amount of water gets into a swimmer's lungs, it can cause inflammation that makes breathing difficult.