Lifting massive vessels weighing hundreds of tons is no easy job.
Oil refineries and chemical plants use large, high pressure vessels in their refining process. To upright these vessels requires two lifting devices: a lead, hoist, or head crane and crane or tailing crane.
Both the lead and tailing cranes should have enough capacity to be able to lift the entire vessel on its own. To do the job, both cranes can be mobile cranes, or the lead crane can be a gantry while the tailing crane can be a mobile crane or hydraulic gantry. The process of lifting such a large, awkward load, requires both cranes to lift the horizontal vessel off the ground. The tailing crane moves the load so the lead crane can lift it vertical.
Also see Creative Solution to a Difficult Job
August 5, 2014 (Sanford, Fla.)—Crane Institute of America announces the availability of the newest edition of the industry’s favorite rigging handbook. Rigging, by James Headley, has been converted from imperial to metric. Providing practical information and great illustrations, the Rigging Metric handbook contains the latest information on wire rope, rigging hardware, and slings, including capacity tables and charts.
“For years, the handbook Rigging has been popular outside the United States for use in training,” said Jim Headley, President of Crane Institute of America. “Customers in Canada, South America, Europe, Australia, and the Middle East have been asking for a metric version of the book.”
Along with the rated capacity tables of slings and rigging hardware, the book covers how to calculate load weight, how to calculate sling loading, and proper load handling techniques. The information is applicable to rigging operations no matter where you are in the world. By offering two versions of the books, trainers and students now have a resource that improves communication, understanding, and safety.
The book can be ordered at Crane Institute’s Online Store and costs $19.95 USD.
About the Author
James Headley has spent more than 40 years working in the crane and rigging industry. After serving a crane apprenticeship through Operating Engineers Local 312 in Birmingham, Ala., he worked as journeyman crane operator until entering the crane training business in 1984.
As President of Crane Institute of America, Jim has developed training programs for hundreds of major companies including aircraft manufacturers, oil and gas producers, utilities, and the military. For over 20 years, he served on U.S. standards boards–ASME B30 main committee on cranes and lifting devices, and sub-committees for cranes, slings, and rigging hardware. Presently he serves on the International Standards Organization (ISO) committee on cranes.
Headley is also...
Something went terribly wrong while three cranes were moving the bow section of a ship in a Mississippi shipyard. One crane overturned and several workers injured.
Cranes are designed to smoothly lift and move loads within their capacity with the boom tip directly over the center of gravity of the crane’s load. When multiple cranes are working together, they share the load, but neither have the load positioned over the center of gravity.
As you can imagine, things become more complicated when three cranes are working in tandem, because the movement of a load has to be perfectly choreographed. In this case, the only safe maneuvers made would be to hoist, lower and travel. Hoisting and lowering shouldn’t be a problem as long as each crane’s share of the load is within its capacity. However, traveling induces dynamic forces on the cranes because they don’t travel in perfect synchronization. Like all equipment, cranes travel at random speeds no matter how careful the operators are to synchronize their speed. Being off by a small amount causes what could best be described as a pushing and shoving match between the cranes.
Industry accepted lift planning models for multiple crane lifts would require that no crane be loaded beyond 75% of capacity. This 25% safety margin is used to compensate for the dynamic forces.
Attend our Mobile Crane Operator training to learn safe operating practices.
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