Finally, consider the complex pulley system shown in Fig. 10.26 where pulleys (3) and
(4) are connected to pulleys (1) and (2), respectively, by rigid links. Pulleys (1) and (2) have the same diameter, and pulleys (3) and (4) have the same diameter.
As there is only one active cable, the mechanical advantage is (4:1), meaning the force ( P) is one-fourth the magnitude of the load (W ). Also, depending on the relative diameters of the large pulleys (1) and (2) as compared to the small pulleys (3) and (4), the upward velocity (vW ) will be some fraction of the velocity (vP ) of the force ( P) as it moves downward.
From the configuration of the pulleys in Fig. 10.26, the lower pulley (2) will again roll like a wheel up the cable that passes around pulley (3), even though this cable is not perfectly vertical. As the separation distance between the centers of pulleys (3) and (4) would be much larger than that shown in Fig. 10.26, the angle by which this cable and the cable that passes around pulley (4) and goes up to the center of pulley (3) is off from the vertical will be small