A Turnbuckle is a basic, often overlooked rigging device that may relieve much stress during challenging or critical lifts. Primarily, turnbuckles are used as a means of adjusting a load in cases of offset center-of-gravity. However, they are beneficial for adjusting tension and reducing slack in various tensioning assemblies, from providing tension in a perimeter cable to constructing a suspension bridge.
This blog will review turnbuckle types, common applications, and installation instructions so you can get started utilizing this convenient tool.
The most common turnbuckle types are: eye and eye, hook and hook, jaw and jaw, jaw and eye, and hook and eye, each named for their combination of end fittings. The fittings are determined by what the turnbuckles need to connect to and whether the solution is permanent or temporary.
Eye and Eye: The eye and eye configuration is designed with a closed-loop teardrop fitting on each end. It’s the most frequently rented and may be used nearly anywhere. The eye and eye turnbuckle is intended for a shackle to be attached on each end, with the shackle pins going through the turnbuckle eyes.
Hook and Hook: The hook end fitting is commonly used to create temporary connections because they are easy to quickly connect and disconnect. However, since the hook configurations lack a safety latch, you should never use them in connections where the tension could unexpectedly release.
Jaw and Jaw: A jaw end fitting consists of a U-shaped jaw and bolt secured together by a nut or pin. This configuration offers the option to join the sling or lifting lug directly to the turnbuckle. In addition, it works well to connect components that cannot open, such as an eye bolt.
Hook and Eye : Similar to hook and hook, the only difference in this configuration is that the eye end allows for one secure end attached to the rigging hardware.
Jaw and Eye: The jaw and eye configuration is nearly the same as the eye and eye configuration, with the added flexibility to directly connect to the lifting lug. This configuration isn’t as common unless you have a fixed point or a lug that’s difficult to work on a lift.
Read more about turnbuckle end fittings in Tools You May Not Know We Rent: Turnbuckles.
As previously mentioned, one useful application for turnbuckles is to make adjustments to help equalize a load and to correct an offset center of gravity. For example, if you needed to have 10 ft 7 ½ inches of total running length but didn’t have a sling of suitable size you could install a turnbuckle to accommodate for the difference by simply adjusting the turnbuckle in or out to get the desired length required for a perfectly level lift.
*Note: When adjusting turnbuckles, we recommend using an appropriately sized wrench instead of a spud wrench or pry bar placed through the body. The latter tends to cause damage to the turnbuckle and could potentially create dangerous repercussions. *
Another use for turnbuckles is when a lift has six vertical pick points, which may require a minimum four-bar system. Any time this situation presents itself, it becomes difficult to ensure you have equal load distribution among the six points. You have the option to place a sling on each of the four outside corners, which means on the two middle lugs, you can place another bar and utilize a shorter sling with a turnbuckle. This will allow you to adjust the tension to achieve equilibrium across all six lugs.
Proper installation of any piece of equipment is essential to maintaining safe and efficient applications and turnbuckles are no exception. After determining the WLL of the turnbuckle is sufficient for your application, follow these steps for installation:
LGH has a wide selection of Crosby turnbuckles in stock and available to rent. For more information, or to request a quote please visit https://www.rentlgh.com/product/turnbuckles/.
For more information Turnbuckle hardware, please get in touch with us!