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.
Wet drownings occur when the spasm relaxes after the victim approaches or goes into unconsciousness, and water can then enter the lungs. Finally, one of the bigger problems when drowning is not damage to lung tissue at all (which is usually mild), but rather concerns blood chemistry.