How Blocks (Pulleys) Work?
Blocks or pulleys are simple machines that have many uses aboard ship, as well as onshore. Remember how your mouth hung open as you watched movers taking a piano out of a fourth story window? The guy on the end of the tackle eased the piano safely to the sidewalk with a mysterious arrangement of blocks and ropes. Or, you’ve been in the country and watched the farmer use a block and tackle to put hay in a barn. Since old Dobbin or the tractor did the hauling, there was no need for a fancy arrangement of ropes and blocks. Incidentally, you’ll often hear the rope or tackle called the fall, block and tack, or block and fall. In the Navy you’ll rig a block and tackle to make some of your work easier. Learn the names of the parts of a block. Figure 2-1 will give you a good start on this. Look at the single block and see some of the ways you can use it. If you lash a single block to a fixed object-an overhead, a yardarm, or a bulkhead-you give yourself the advantage of being able to pull from