Abstract: A pre-fabricated tourniquet that is easy to apply, that ensures consistent and even circumferential pressure, that is lightweight, that provides standard life saving operation, and that can be utilized in any setting or situation, and related methods are provided. Mechanically constricting tourniquet apparatus and related methods are provided that are comprised of a tourniquet body, a carriage, a torsion bar, a receiver, and a slider. The tourniquet is long enough to encircle a human limb, for example, an arm or leg. The tourniquet apparatus includes several features for preventing or otherwise limiting harm to users and/or damage to the tourniquet apparatus itself.