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Basic Mobile Crane Safety. Colin Perkins Safety Director Malcolm Drilling Co., Inc. Overview. Crane accidents are often the most costly of construction accidents when measured either in dollars or worse . . . LIVES This presentation will be a basic
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Basic Mobile Crane Safety Colin Perkins Safety Director Malcolm Drilling Co., Inc.
Overview Crane accidents are often the most costly of construction accidents when measured either in dollars or worse . . . LIVES This presentation will be a basic overview of the do’s and don'ts of safe mobile crane operation
Crane-Related Deaths in Construction From 1992-2006 323 – total recorded crane-related deaths from 307 incidents in construction 12 multiple-death incidents involving a total of 28 deaths Source: U.S. Bureau of Labor Statistics Census of Fatal Occupational Injuries Research File
Causes of Crane-Related Deaths in Construction, 1992-2006 * 52 of 59 struck by booms/jibs were due to falling booms/jibs ** Other causes includes 14 struck by other crane parts and 9 highway incidents. Source: U.S. Bureau of Labor Statistics Census of Fatal Occupational Injuries Research File
Ancient Cranes Ultra-Modern Roman Crane Very Early Greek Crane
Is This A Crane? This is a Crane with a drill attachment suspended from, and attached to, the crane. It is NOT a dedicated or self-contained drill rig.
Is This A Crane? This is a dedicated or self-contained drill rig used for the installation of drilled shafts or caissons. While it may have some very limited lifting capacities, it is NOT a crane.
What Can We Do To Keep “IT” From Happening? What “pro-active measures” can we incorporate in our operations to keep crane accidents from happening?
Operator Training Supervisor: Hey, can you run this crane? Prospective Operator: I don’t know, but I am a quick learner! Can you start today??
Operator Qualification Remember – It is the responsibility of the EMPLOYER to insure the crane operator is qualified to operate the specific crane he or she is to operate. This is not the responsibility of the “Union”.
Crane Inspections Annually Periodically Daily Each are documented along with logs of repair or replacement items
Crane Inspections Monthly Inspections Documented Kept on file for three months Annual Inspection Documented Detail inspection criteria Functional testing Kept on file for 12 months or next annual inspection • 13
Crane Inspections Severe Service Shock load, corrosive atmosphere, etc. Inspect exposed items/conditions Document Not In Regular Use Idle more than three months Monthly inspection must be performed Document • 14
Wire Rope Inspection Shift Inspection Monthly Inspection Annual Inspection • 15
Crane Inspections The wire rope on the crane must be inspected along with the machine itself. Often overlooked are the standing ropes. Most refer to these as the “pendent” lines. While they do not move per se, they are in constant tension and vibrate continuously. One broken wire near the socket, is sufficient cause to remove the pendent line from service. You must replace the pair, as a new line will be shorter than a used line. All of the crane’s suspended weight is supported by the pendent lines. At a minimum, they should be inspected at rig up and tear down.
Crane Lifting Capacity Cranes are set up a a test pad which is level, stable, & dry. No wind, rain, snow, mud, or supervisor indicating a need to accelerate your production! In other words. . . Cranes are load tested under “IDEAL CONDITIONS” So, your 100 ton crane will never lift 100 tons on your site because you do not have it rigged properly and you don’t work under “ideal conditions”.
But It Has A Computer . . . A crane’s computer is an operational aid. It does not run the crane. The operator, using their training and skills operates the crane. The operator must use information supplied by the riggers (load weight, working radius, rigging selection), the crane’s load chart, and their assessment of the working environment to decide whether or not to make the lift.
How Much Does It Weigh? So how much does 80’ of your piling leads and hammer weigh? How heavy is that 66” x 45’casing anyway? Did you add all of that concrete stuck to the sides? If you are extracting a pile or casing from the soil, how much more weight (in resistance) is there?
Structural Overload Did you finally find the “override” switch for the computer?
Ground Conditions Most often, the deep foundation contractor is one of the first to arrive to a jobsite. Typically, the site needs some improvement. If underground utilities, vaults, poor soil conditions are not identified before we get onsite, or dealt with once we arrive, bad things can happen to cranes.
Ground Conditions Improper method to determine if there is a septic tank under the rig.
Ground Conditions Improper use of crane mats Proper use of crane mats to enhance poor ground support
Blocking For Outriggers Close, But No Cigar . . . .
Blocking For Outriggers Creative, but incorrect Correct
Take Too Long To Set Up? Perhaps, next time they will take the time to set up correctly, even just for one pick.
Power Line Contact Remember . . . The Number One Killer Of Employees Working With A Crane Is Contact With An Energized Overhead Power Line. A minimum distance of 20 feet must be maintained at all times between the crane and energized overhead power lines. Power must be de-energized, lines moved or otherwise rendered harmless before any work activity closer than 10 feet can begin.
Power Lines In Crane Operations You must identify work zone and either mark boundaries, use range limiting devices or range control warnings You must determine if any part of crane, line or load could get within: 20 feet of a power line 350kV or less 50 foot for all lines over 350kV If yes, you must either: De-energize and ground Maintain 20 or 50 foot clearance Use table A and conduct a planning meeting with crew • 30
Rigging Inspection An often overlooked rigging item is the overhaul ball, hook, and swivel. Make sure the capacity is clearly marked on the swivel and the hook. If not equal, or the swivel being the greater, you may overload the swivel, because of the capacity noted on the hook. Note: Swivel assemblies will eventually loosen up, and come apart under load if not inspected and maintained daily.
Power Line Contact A clear indication that rubber tires do not “insulate” you for the electricity above
Rigging Capacities You should always have ready access to a rigging capacity chart
Lift Plans Typically, if you are going to make a pick that is 75% of the crane’s lifting capacity (at a given radius and configuration), or making a multiple crane pick, a lift plan should be generated to help insure success of the lift. Using a checklist, and perhaps a drawing, can help identify any problems before they arise.
Answers You Should Know Q. What is the “working radius”? A. The horizontal distance from the center of rotation to the center of the load hook. Q. How much does the load weigh? A. Load + rigging + wire rope = total weight Q. When was the last crane inspection? A. Should be today’s date.