Traditional hand chain hoists are a known commodity within the lifting and rigging industry as one of the most versatile and reliable rigging choices for a variety of different projects. However, much like any other piece of equipment, hand chain hoists have their limitations. That is where lever hoists can save the job.
Breaking down the difference between the two is as simple as looking at the direction the load needs to move. While a hand chain hoist is a great option for vertical and angular lifting, they are not suitable for horizontal pulling. Lever hoists, in this case specifically referencing come-a-longs and Griphoists as manual options with greater degrees of precision, have the ability to operate both vertically and horizontally with no difference in setup or capacity.
Let’s say you are replacing a load in a facility with nearly no headroom to fit a clamp/trolley and hoist above or skates below at the final position. The final placement needs to be exactly where the old unit was and the site does not allow for a winch to be anchored into the ground, what do you do? This is a great application to break out a lever hoist.
To start, we should probably quickly go over the difference between a come-a-long and a griphoist. Most often, when people think of lever hoists, their first thought is a chain come-a-long.
Come-a-longs operate with a ratchet and pawl that rotates a gear to pull the chain along a straight path. While slow-moving, come-a-longs provide greater precision in load movement than can be achieved with a traditional hand chain hoist. Come-a-longs also allow loads of up to 18,000 pounds to be moved with less than 80-pounds of force on the lever. Since the levers are engineered for optimal safety, it is important to never resort to the use of cheater bars or other means of misusing a chain come-a-long. Griphoists, also commonly referred to as a Tirfor, operate instead using specially designed wire rope that allows two grip-jaws inside the unit to clamp down on the wire rope, alternating which jaw is activated, similar to a hand-over-hand pulling method. The only limit to the length of pull available with a griphoist is the length of rope available in your fleet or from your local distributor, but remember, you must ensure that the wire rope you are using is designed for use in a griphoist. You can see a quick overview of a griphoist here.
Now, let’s head back to our load to determine the best course of action. With the bolt-down restriction, the first step is to have an engineer determine the viability of any anchoring points where the lever hoist can be mounted as a base. Provided there is a safe column/structure with a clear line-of-sight, it’s now time to set up your hoist and begin the move. The first step is to determine the force required based on the weight of the load and the coefficient of friction as we’ve discussed in previous blogs.
Griphoists are available in capacities of up to 4-ton (without recruiting sheave blocks that would increase the capacity using mechanical advantages) while a come-a-long is available in capacities ranging up to 9-ton. Knowing the exact force required, you can make an informed decision on which option works best for you between the two. A situation such as this that would have otherwise proven impossible or far more difficult to complete can be handled with ease with the use of a lever hoist. For help on your next project or in selecting the right tool for the job, please reach out to your local representative or give us a call at 800-878-7305 to speak with one of our rental specialists.