Modern grappling hooks were originally designed for naval warfare during the days when ships were powered by wind and sails. Large fishhook shaped objects would be attached to a stout rope, then thrown or attached to a projectile and fired toward the sails and rigging of an enemy ship. The ropes would be used to secure or board the ship. Old-style naval warfare is rarely employed anymore, but the military and extreme sports enthusiasts have found a variety of uses for the grappling hook, including climbing.
The origins of the grappling hook are lost to the mists of time. References are made to the use of grappling hooks by the Vikings, the ancient Greeks, the Egyptians and, in popular mythology, by the Ninjas in Japan. The multiple fishhook design of most ancient grappling hooks argues for a nautical source as its inventor, but the hooks appear to be used most frequently in ancient warfare as a means of pulling down obstructions or for climbing walls or mountainous terrain.
As a climbing implement, the grappling hook serves as a means to secure one end of a rope to a fixed object, allowing the climber to either slide down the rope to a lower surface, to use the rope as a hand hold for climbing up to a higher point, or, in conjunction with a Swiss Seat harness, to rappel. The hook portion of the tool may be wedged in place around an immovable object such as a boulder, large tree or even a solid structural surface. A rope, which is tied to the eye of the grappling hook, provides the gripping surface.
Contemporary climbing grappling hooks come in three types. A fixed grappling hook is the simplest type of hook with tines that are fixed into place. Collapsible grappling hooks have arms, or tines, that can be folded down alongside the shaft for easier carrying. The tines may be spring loaded or expanded manually, depending on the design of the grappling hook. Retractable grappling hooks are the newest development in the device. These lightweight, extremely tough grappling hooks have been designed for military use and can retract to a size small enough to fit into a canteen pouch.
Grappling hooks that are used for climbing may vary widely in appearance, but most have three common features. There is a central shaft that connects the grappling arms or tines. At one end of the shaft there is an opening, or eye, through which a rope is inserted. On the other end of the shaft there are at least three, but possibly more, equally spaced grappling arms or tines. While most grappling hooks are designed to be thrown by hand, some modern retractable models have an aerodynamic shape and are engineered to be propelled by a rocket or fired like a projectile from a specially equipped rifle.
Using a grappling hook for climbing can be exhilarating, but it can also be very dangerous. It should never be attempted without proper training and with competent supervision. The grappling tines can be heavy and sharp. If thrown improperly they could hit a bystander and cause serious injury. If the tines do not catch, the falling hook could hit the thrower and cause serious injury. Always test the security of the line and its ability to hold your weight prior to committing to the climb.