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.
Dry drowning occurs when a person's lungs become unable to extract oxygen from the air, due primarily to: 1  Muscular paralysis. 2  Puncture wound to the torso (affecting ability of diaphragm to create respiratory movement)  Changes to the oxygen-absorbing tissues.