The survival knife has certain characteristic which were important at this stage of my thinking. The survival knife has a comfortable handle for easy gripping. the survival knife is readily thrown by the handle and can travel a good distance controllably, with practice. The survival knife already has a ring at the pommel or end of the handle to which a line may be attached. Therefore a survival knife with its usual weight of 10 to 24 oz. can be a very suitably weighted line carrier. It lacks any way to secure the knife temporarily to any object so as to support any load.
I determined that if at least one rearwardly directed sharpened member could be attached to a survival knife to act as a grapple point, that the survival knife could function as a very valuable grappling device.
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The quillon or hand guard is located at nearly the center of gravity of the survival knife and its tips provide a point for possible attachment of one or two grapples provided the quillon has sufficient strength to transfer load to the knife handle without bending. Given a quillon dimensioned to support a load of 600 pounds and a thickness sufficient to provide 5 or 6 thread turns, I determined that the quillon can function to secure a grapple. Since the quillon usually extends from both the top and bottom edges of the knife blade, two grapples can be attached, one to the top and the other toward the bottom, thereby increasing the probability of a good hook being obtained on the initial throw of the knife with the grapples attached.
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I have also determined that it is possible to produce a skeletal type survival knife in which the grapples pivot into engagement with the handle portion when not in use and form a rounded handle. When pivoted outwardly, the grapples function fully to make hook-like engagement with any object it encounters when the casting line is drawn in.
Each of these embodiment provide effective grapple capability for survival knives.
