Crane training (p.1)

Safety Instructions
• Do not lift people and never ride the hoisting load.
• Do not lift load over people. No one shall be under the hoisting load.
• Make sure the sling is well balanced. Avoid tip loading, and loading on hook latch.
• Never lift the load over the rated capacity.
• Do not operate with kinked, twisted or damaged chain.
• Avoid side pull or end pull, and quick reversal operations.
• Never leave the suspended load unattended.
• Make sure you take up slack slowly.
In addition to improper rigging, cranes hitting overhead obstacles represent the most frequent hazards of crane operation. Before beginning a lift, clearly inspect the entire proposed path of the crane, paying particular attention to overhead obstacles (especially overhead electrical hazards which could be fatal) and whether the path of the crane will pass directly overhead of any individuals. Always have a spotter available, particularly in blind spots. Never exceed the crane capacity and never attempt a critical lift unless you have years of experience in utilizing the CAMD crane. A critical lift is defined as one exceeding 90% of the rated capacity of the crane. For the CAMD crane, a critical lift is greater than 3600 pounds. A crane is a vertical lifting device. It should never be used to drag or pull a load. Always position the crane directly perpendicular to the load to be lifted. Non-vertical lifts can
damage both the crane and the rigging materials and may result in improper wrapping around the drum. If the drum wraps are not seated in the proper position, immediately cease crane operation and inform facility maintenance. An operator who leaves a load suspended and unattended is subject to disciplinary action, which may include revocation of his or her license to operate the crane.
Checking Limit Switch
• Move crane to open area.
• No load should be on hoist lines.
• Slowly run (#2 position) block up to 3’ from limit switch and stop.
• Continue to raise hook slowly (#1 position).
• If limit switch does not operate at point where it should, don’t use crane.
The first procedure in any crane lift is to assess the valid performance of the limit switches of the crane. To accomplish this task, run the length of the crane rope to the lower limit. For CAMD, this limit is approximately 4 inches from the floor. Make sure that at least 2.5 wraps remain on the drum. Once the lower limit switch has been tested, raise the crane hook to the upper limit switch, all the while making sure the rope wraps correctly. There should be no cross wrapping or ill sitting of the rope on the grooves of the drum. Ensure the top limit switch stops before hitting the drum. As you approach the top limit switch slow the crane from the fastest position (3) to the slowest position (1) to prevent hitting the upper limit. If either limit fails the crane should be locked out. The electrical control panel for the operation of the crane is to the left of the experimental hall door (on the receiving side) adjacent to the log-out tags. Pull the lever down to place in the off position.
Inspection and Maintenance
• Inspection and lubrication are done twice yearly.
• Daily before operating:
o Check battery
o Check all controls
o Visually inspect
Wire rope for kinks or damage
Sheaves, drums for damage
Upper and lower limit switches.
CAMD maintains a rigorous inspection program. All maintenance is performed only by qualified personnel. Being a qualified CAMD crane operator does not qualify one as
maintenance personnel. Maintenance is required whenever a wire has wrapped incorrectly on the drum or a limit switch fails in either the upper or lower modes. In case of any suspected failure the operator must immediately cease operation, remove power from the crane and inform the facility management or CAMD safety. Place a lockout tag on the remote control unit. All CAMD crane operations are conducted using the portable remote control for the crane. After retrieving the remote control, check the level of the battery. If the battery does not register in the green, replace the battery before continuing. Collect suitable slings for properly securing all loads. Examine slings for any defects. Before beginning any lift, check upper and lower limit switches without any weight attached. The crane limit is 2 tons (4000 pounds) which must include the weight of all rigging equipment. A scale is available to check overall weight. Once the crane has been established to be working properly, rig the load properly, attaching tag lines for loads which might be susceptible to swing. Always ascertain that the area over which the load will travel, is free and clear of personnel or other potential obstacles.
Rigging
• Loads should be well secured.
• Slings should be adequate to the task.
• Slings should be unkinked and load balanced and secured.
• No sudden stops.
• No obstructions while lifting or traveling.
• No loose items on load or crane before lift.
• Bumping into runway stops is prohibited.
• Hoist line must be vertical prior to the lift (remove slack in the hoist slowly).
• No crane load should pass overhead of personnel, clear the area before making the lift.
• No one is to ride the crane without permission.
The most important job of any crane operation is rigging of the load. Poor rigging may result in personnel injury, property damage, or other serious hazards. Rigging is the most time consuming of any crane operation and represents the single most hazardous potential of crane operation. In a multi-sling operation, each leg must be of the same length and must contribute equally to load distribution. Nylon slings are susceptible to damage by sharp corners on the item to be rigged. Caution must be taken to ensure that slings are not damaged by sharp corners or by excessive loading. Rigging requires years of practice to perfect. If in doubt about the security of your rigging, ask for help.
Rigging should be checked by lifting the load a few inches off the ground to ensure that no swing develops and that the load is completely secure. Remember it is important to take the time to accomplish this task correctly. Not doing so may result in catastrophic
consequences. One of the most important things to check before lifting a load is to look for loose items, such as screws or tools which may have been used to secure the load. Such items can become projectiles during a lift. This is the reason why crane operators or especially tag line operators should wear hard hats when operating the crane and why it is essential to make sure the path of the crane does not pass over the head of any individual.




It is always important in rigging practice to rig the load so that it is stable. A stable load is one in which the center of gravity of the load is directly below the main hook and below the lowest point of attachment of the slings.The center of gravity of an object is that point at which the object will balance. The entire weight may be considered as concentrated at this point. A suspended object will always move so that the center of gravity is below the point of support. In order to make a level or stable lift, the crane or hook block must be directly above this point. Thus a load which is slung above and through the center of gravity will be stable and will not tend to topple or slide out of the slings.
Predicting the center of mass for an object to be lifted is not a trivial matter. It may require several attempts at rigging to find the appropriate balance point. Many objects are not rectangular such that predicting the center of mass is often difficult. In all crane lifts the center of mass must remain below the hook and below the point of attachment for any rigging. A center of mass above the hook is inherently unstable and will cause the load to flip. Similarly, loads which are not balanced in the horizontal plane may slip from the rigging. The overall stability of the load is a combination of balance with respect to center of mass, weight distribution, and rigging tightness.


0 comments: