Those of us not familiar with the term might be picturing grabbing a hold of a rigging configuration by the shackle and hanging on for an eight-second ride. As fun as that sounds, it is not bull rigging. In short, bull rigging is the term used to describe a method or system of rigging commonly used where a crane (mobile/ overhead) cannot gain access. Bull rigging is often referred to as drifting, "Tarzaning," or simply hand rigging. It is often used in concert with other rigging activities such as transferring a load from a structure to a crane hook or vice-versa.
The equipment most likely to be used in bull rigging includes:
- Chain falls.
- Come-a-longs or lever hoists.
- Rollers/casters/skates.
- Jacks (mechanical or hydraulic).
- Winches.
- Rigging blocks.
The planning and application of using chain hoists and other similar devices to drift loads (moving horizontally while being suspended), skidding/skating loads (pulling a load horizontally on rollers or other equipment), or building a winch and block system to aid with either, takes great skill and careful considerations regarding the forces that we create by building rigging systems.
Necessary training
OK, so what exactly does it take to be a bull rigger?
To start, an excellent knowledge base of equipment uses and applications is a must. In addition, an understanding of the theory behind these unique load handling challenges make for an effective and, most importantly, a skilled bull rigger. The theoretical understanding should focus on these six points:
1.Load weight estimation
2.Discovering the center of gravity and its effect on the load
3.Finding load weight distribution and identifying the share of the weight
4.Understanding tension when working with angles and level or off-level pick points, as well as the influences it has on the rigging and supporting structure
5.Determining the force required to pull a load up an inclined plane or hold a load back when lowering
6.Calculating mechanical advantage as well as associated block loading and frictional gain in a multipart winch/block system
Trust the experts
If you want to become or train a bull rigger, seek out an organization that offers training courses 100-percent dedicated to bull rigging operations. More than half the course should involve hands-on activities and focus on moving loads into and out of a two-story engineered bull rigging structure.
Joe Kuzar is the technical director of Industrial Training International (ITI). He is a National Commission for the Certification of Crane Operators (NCCCO)-certified lift director and member of the ASME P30 -- Lift Planning Main Committee.
For more information, visit www. iti.com/bull-rigging-preview or call (800) 727-6355.
