The large, heavy-duty block hanging in the mast or [[derrick]] and to which the hook is attached. The traveling block supports the drill column and "travels" up and down as it hoists the pipe out of the hole and lowers it in. The traveling block may contain from three to six sheaves depending upon the loads to be handled and the mechanical advantage necessary. The cable from the hoisting drum on the drawworks runs to the derrick's [[crown block]] and down to the traveling block's sheaves.

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