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.
Starfish starfish produce large numbers of oocytes that are easily isolated; these can be stored in a pre-meiosis phase and stimulated to complete division by the use of 1-methyladenine. Starfish oocytes are well suited for this research as they are large and easy to handle, transparent, simple to maintain in sea water at room temperature, and they develop rapidly. "Asterina pectinifera", used as a model organism for this purpose, is resilient and easy to breed and maintain in the laboratory. Another area of research is the ability of starfish to regenerate lost body parts. The stem cells of adult humans are