Job sites do not always come with much elbow room. Tight spaces are surrounded with hazards, including many workers, pieces of equipment and nearby structures.
Mobile cranes are perfect for lifting loads in spaces where there is little room to move around, although one false move can result in disaster. That is why there is a strong business case for making the job site as safe as possible.
Types of Mobile Cranes
There are several different types of machines called “mobile cranes”:
• A swing cab crane lets the operator turn 360 degrees, to perform work in all directions;
• A fixed cab crane requires that the driver be stationary and always look straight ahead;
• Hydraulic boom cranes (also known as telescopic boom cranes) use booms that can be maneuvered to raise and lower like a lattice boom, but the arm can also be retracted or extended. The boom can also rotate from side to side;
• A lattice boom crane lifts in a straight up-and-down movement, with the boom performing all the heavy lifting.
OSHA Designations Reflect Level of Training
The reason a mobile crane is so functional in confined areas is due to its mobility and footprint. (The footprint is the area needed to set up a crane to position its outriggers to lift the load while following the crane chart regulations.)
It requires specific levels of experience and training to maneuver these cranes the right way. In the crane industry, you will hear terms like “competent, qualified, and certified persons.”
What do these mean?
• A competent person is “capable of identifying existing and predictable hazards… and has authorization to take prompt corrective measures to eliminate them.” Generally, someone who is competent has the authority to take remedial action when something goes wrong and has knowledge relative to the job.
• A qualified person has “a recognized degree, certificate or professional standing, or who by extensive knowledge, training and experience, successfully demonstrates the ability to resolve problems” relating to the job. A certificate of training would count, as well as several years of experience in the area even if it never involved any classroom training.
• A certified person is someone that has passed “written and practical exams related to the work that he will perform.” Accredited organizations like the National Commission for the Certification of Crane Operators (NCCCO) and others offer certification testing for crane operators, signal persons and riggers.
OSHA 29 CFR 1926. 1400 requires signal persons and riggers working with mobile cranes to be qualified persons. Therefore, certification is recommended but optional. On the other hand, all mobile crane operators working in construction need to be certified persons.
Preliminary Inspections are Important
Before a job, a qualified person must provide proof of an annual safety inspection that follows the Federal Occupational Safety and Health Administration and Department of Labor regulations, along with any state regulations, depending on the project’s location.
In several states, cranes that lift using rolling outriggers or the jib attachment require a current certification showing that the rolling outriggers and jib have been proof load tested by a qualified person. (This is a stress test that demonstrates the fitness of a rescue strop or load-bearing structure. These requirements apply solely to lattice boom and telescopic cranes.)
You should not use modified or damaged slings. Alloy steel chain slings should have permanently attached information about grade, size, inspection date and rated capacity.
Metal mesh slings need to have their rated capacity for choker hitch loadings and vertical basket attached. Lastly, you must carefully inspect synthetic fiber and natural fiber rope slings and wire rope slings for evidence of corrosion, heat damage, broken or worn down fibers or wires.
In every state, during operation, keep a durable load chart within reach of the operator. This chart has a full range of crane load ratings consistent with the recommendations from the manufacturer. Also, include warnings about equipment limitations in the load charts.
Safe Lifts Are No Accident
It goes without saying that you should rig every load properly (i.e., balanced in the sling and well-secured). The hoist rope should be free of kinks, and the multiple part lines should not be twisted. The operator must bring the hook over the load—refraining from swinging—and, after attaching the load, avoid raising it over other workers.
When lifting a load approaching the rated load weight, the operator must use the crane’s brakes to test them after raising the load a few inches.
It is crucial that the operator remain aware of the appropriate chains, sling and hoist requirements while the load is suspended. He should not lower the load past the point where less than three full wraps are left on the hoisting drum.
Critical Lifts Need Additional Planning
You can define a critical lift as one that (1) is over 75% of the crane’s rated capacity or (2) demands the use of more than one crane or derrick to carry it out. A written lift plan is necessary when doing these lifts. The plan must incorporate load chart data, information about the crane, an analysis of subsurface and soil conditions, an emergency plan, detailed diagrams of the lift and more.
Attention to detail and preparation require mobile crane operators and the contractor/owner who hires them, as well as the workers that are part of the project, to have a documented and established plan before the job starts.
Qualified, competent or certified persons will work with the safety officer and other personnel relevant to starting the system whether the lift is carried out at a loading dock, construction site or petrochemical plant.
About the Guest Author
Larry Collier Crane Parts & Service is a comprehensive resource for high quality factory stocked crane parts, crane repair and rebuild services, diagnostic assistance and more.
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