Shear legs to the gin pole, derrick and tripod (lifting device). Shears are an A-frame of any kind of material such as timbers or metal, the feet resting on or in the ground or on a solid surface which will not let them move and the top held in place with guy-wires or guy ropes simply called "guys". Shear legs only need two guys whereas a gin pole needs at least three. The U. S. Army Field Manual FM 5-125 gives detailed instruction on how to rig shears. Fixed shear legs are most commonly found on floating cranes known as floating sheerlegs.
Crown-of-thorns starfish damage includes a major section of the disk together with arms, the number of arms regenerating on the disk may be less than the number lost. Another hypothesis is the "aggregation hypothesis", whereby large aggregations of "A. planci" appear as apparent outbreaks because they have consumed all the adjacent coral. This seems to imply that there is apparently a dense population outbreak when there has already been a more diffuse population outbreak that has been dense enough to comprehensively prey on large areas of hard coral. Female crown-of-thorns starfish are very fecund. Based on the eggs in ovaries, 200, 300