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.
Story highlights. 1  Secondary drowning occurs when water in the lungs prevent blood oxygenation. 2  Symptoms include coughing, shortness of breath, chest pain, lethargy. 3  Secondary drowning symptoms appear one to 24 hours after water exposure.