Tackles having more than three sheaves to a block, such as the four-fold, five-fold and six-fold purchases, are not provided as upper deck tackles because they are too cumbersome to handle efficiently and because the friction in their sheaves considerably reduces their gain in mechanical advantage.
Intambo zesikhephe zineshivs ezingaphezulu kwesithathu sovingco esinjengesine sosongelo, usongelo lwesihlanu kunye nentengiso yosongelo lwesithandathu, alunikelwanga njenga ngaphezulu, komgangatho wentambo zenqanawa kuba zingaxaka kakhulu ekubanjweni kwaye uxinzeleloelukwishivs lungehlisa ungeniso kuncedo lomatshini