For what you ask? For fleet angle.
Using a winch to lift or position a load gives your project flexibility because you can have this material handling muscle positioned in various ways. You can place the winch above the load and use it vertically as a hoist, or have it on the same level of the load to pull horizontally, or use pulleys with it so you can position the winch where you want it and move the load in the direction(s) that you need it to go. But when you are determining where to position your winch, it is important that you consider the critical distance needed to maintain the necessary fleet angle to keep things safer and in proper working order.
What is fleet angle? Fleet angle is the angle between the wire rope and an imaginary line extending perpendicular to the drum. This angle varies with the width of the drum and the distance between the lead sheave and the drum. The proper fleet angle helps the wire rope to wind evenly onto the drum, and helps to reduce wear to the wire rope, drum, and lead sheave. Too large a fleet angle will cause the wire rope to wind loosely, overlap and possibly jump the flange and cause severe damage to the equipment. That’s why it’s important to properly distance the winch from the lead sheave (also sometimes called fixed sheave) when you are determining where to position your winch. A maximum fleet angle of 1-1/2° for smooth drums, and 2° for grooved drums, helps the wire rope wind uniformly. A narrower drum can also help stay within the recommended fleet angle if the critical fleet angle distance can’t be improved. Diagrams below are examples of common rigging layouts that show where critical fleet angle distances are to be measured so you can stay within the proper maximum fleet angle. |
So next time you want to take advantage of the benefits of using a winch to move or position a load, make sure you are practicing proper distancing…fleet angle distancing.