Triple Block

size of

0uock or shell sheave pin

COTTER pu

hook inner strap --outer strop

— center strap — becket 90lt --9echet hook inner strap --outer strop

— center strap — becket 90lt --9echet e. Use equipment that Is in good condition and ai proper size. Do not use old frayed rope or rotted timbers.

/. See that ail supports and holdfasts have a firm base and that cribbing has level foundation and is built up vertically. g. Do not?put your foot In bight of a running rope or step on or across a taut rope.

h. Do not hang or lean on guy lines.

I. When two or more men are lifting or hauling together, the preparatory command is lay hold, and strength is exerted at command HEAVE. When movement is sufficient, man in charge will command EASE AWAY. At this command, slack oil slowly to insure that load is secure before releasing Its support.

j. Whenever possible, have lines snubbed around trees or holdfasts, so that in case of trouble load can be safely held in position. 55 jj

DOUBLE BURTON (MECHANICAL ADVANTAGE: QV

OOUBLE BURTON [MECHANICAL ADVANTAGE: II).

OOUBLE BURTON [MECHANICAL ADVANTAGE: II).

DOUBLE LUFF (2-FOLD TACKLE) (MECHANICAL ADVANTAGE : 5).
LUFF ON LUFF (MECHANICAL ADVANTAGE: 16).

Ficubk 58.—Compound tackles. Examples of block and tackle rigging, skewing mechanical advantage. Bach p repreaentq a rope which supports an equal part of the weight acting on the whole tack,e- 56 32-34

Was this article helpful?

0 0

Post a comment