Riggers are integral to every lift. With their skills and safe operations below the hook, crane operators can do their job with confidence, knowing their load is safe.
The responsibilities of a rigger are numerous – from selecting the right hardware, to attaching the load to the crane hook. Riggers should be familiar with a variety of equipment and aware of the OSHA and ANSI/ASME standards that govern their particular work site.
Here are some of the types of cranes you may have to rig for:
Called "mobile" since they can move around on the job site. There are two different subsets of crane, categorized by their boom type:
- Lattice boom cranes
- Telescopic boom cranes
- Articulating boom cranes – also known as “knuckleboom” cranes
Mobile cranes can be further classified by the type of truck chassis, turntable and wheels they are fixed to.
- Crawler cranes
- Rough terrain cranes
- All-terrain cranes
- Boom trucks
Overhead cranes are a type of fixed crane, operating on the same course/jobsite each day. Each crane is specifically tailored to a single place and purpose.
- Bridge Cranes
- Gantry Cranes
- Monorail Cranes
- Jib cranes
- Workstation cranes
These are most often used off-shore, but can also be found in dockyards. They have the appearance of a lattice boom crane but are supported by a fixed pedestal.
The most visible of all cranes, their adjustable height gives them great reach as well as the flexibility to grow in size with the construction itself.
The riggers on any job have a large number of responsibilities. These include:
- Knowing the weight of the load
- Knowing the center of gravity of the load and attaching the appropriate rigging directly above it
- Selecting the correct hitch
- Selecting the correct sling
- Inspecting all rigging gear prior to use
- Protecting the rigging from sharp surfaces
- Following correct D/d ratios on wire rope and chain slings
- Equalizing loading on multiple legged slings
- Calculating sling angles
- Keeping personnel clear of the area
- Using proper hand signals
- Maintaining load control
Selecting the right hardware for each lift is critical. Riggers need to understand the limitations and applications for each type of hardware they select.
- Alloy chain
- Wire Rope
- Metal Mesh
- Screw pin type
- Bolt type
- Anchor shackles
- Chain shackles
- Synthetic sling shackles
- Vertical hitch
- Bridle hitch
- Basket hitch
- Choker hitch
- Grommet slings
- Braided slings
To properly execute a rigging job, it is essential to have a good grasp of several mathematical concepts:
- General concepts such as the the ability to calculate the area of a triangle (1/2 x A x B)
- The ability to calculate a load weight based on a reference sheet that lists the pounds/cu. ft of typical materials and liquids. For example, did you know that at 150 pounds /cu. ft, reinforced concrete is actually ‘lighter’ than aluminum (168 pounds/cu. ft)?
- Load factors and weight distribution, especially the formula to calculate sling tension
- How to position pick points
- Sling capacities
- Load chart calculations
At the end of 2021, ASME B30.5 was updated to include a requirement for qualified riggers.
The following four items are key:
- At least one qualified rigger must be present on any site utilizing a mobile crane.
- Only the employer can designate the rigger as qualified.
- To be designated as qualified, the rigger must have proof of the successful completion of a written and practical examination covering the topics specified in the standard.
- This standard applies to any industry, not just construction.
Formerly, OSHA only required a qualified rigger under limited conditions. A rigger was considered qualified when they:
- possessed a recognized degree, certificate or professional standing,
- had extensive knowledge, training, experience and can successfully demonstrate the ability to solve rigging problems relevant to the job at hand.
Rigging Training & Certification
OSHA does not require training for riggers, but ANSI/ASME B30.9 and B30.26 specify that users of all types of slings and rigging hardware shall be trained in “the selection, inspection, cautions to personnel, effects of environment and rigging practices”.
There are several levels to which riggers can be trained. While terms like ‘journeyman’ and ‘master’ rigger are used more often in Europe, in the USA, there are two different routes to follow.
The first is through the national certification authority, National Commission for the Certification of Crane Operators (NCCCO). In this case, the levels of training might look as follows:
However, as mentioned above, certification is not mandatory for riggers. It is possible, instead, to follow a different route of training, one which is customized to the particular industry or equipment the individual(s) work with on a daily basis. A training program could be based around the following steps:
Regardless of the route you choose, any rigger training should include these fundamentals.
Test Your Knowledge
It is important that riggers and supervisors know that there are OSHA and ANSI/ASME standards and regulations that apply to operations below the hook.
- ANSI/ASME B30.20 – Below the Hook Lifting Devices
- ANSI/ASME B30.9 – Slings
- OSHA 1910.184 – Slings
- ANSI/ASME B30.26 – Rigging Hardware
- OSHA 1926.251 – Rigging Equipment for Material Handling
- ANSI/ASME B30.5 – Mobile & Locomotive Cranes
In order to work well with your crane operators, it is also useful to be aware of the applicable crane standards:
- How long is rigging training good for?
All NCCCO rigging certifications are good for 5 years. CICB rigging certifications are typically valid for 2-3 years, depending on the program taken.
- What is the primary requirement of a rigger?
Fundamentally, a rigger is someone who connects and disconnects the load. The ANSI/ASME standards list 8 responsibilities of a rigger. The depth of expertise necessary in each of these responsibilities depends on the position held. Just as there is usually more than one rigger for each job, there is more than one type of lift that requires a rigger.
- What is a master rigger?
This is a term more frequently used in Europe than in the USA and designate4s an advanced rigger, usually an engineer. In the US, it has no regulatory or legal bearing, unlike in the EU.
- Is rigger a good job?
For many, being a rigger is the starting point for a career in the lifting industry, often for those who would like to work their way up to being a crane operator. Rigging is frequently considered an additional duty rather than a specific job on the worksite, making it a useful additional skill set to have. For those who work on more complex and demanding lifts, being a rigger is a challenging but rewarding job with a lot of responsibility.
- What is the most common misuse of rigging?
The misapplication of rigging is unnecessarily common. In particular, applying rigging to edges without softeners, or choking on attachment points.
- What are the 3 types of slings?
Slings typically come in three materials:
- Wire rope
- How do you plan a crane lift?
Depending on the complexity of the pick, planning a crane lift could be a very involved process. At its simplest, a plan needs to include the following:
- Start with the load – understand the weight and the center of gravity
- Evaluate the equipment being used – the crane and rigging
- Evaluate the location and environment
- Plan the operation – which personnel will be involved, what does the flight path look like, will taglines be used