A crane hook is a device used for grabbing and lifting loads. As a vital component of a crane’s proper functioning, you are required to schedule both a manual and visual hook inspection at regular intervals. The frequency of these inspections depends on the type of equipment on which the hook is used, however, there must be at least one inspection conducted annually.
There are certain instances that require the immediate removal of a crane hook from service. Please note that a crane hook inspection should be conducted by a designated person and followed up by a qualified individual if a potential issue has been detected. This blog provides a crane hook inspection checklist and requirements to help you get started.
Crane hook inspection checklist: What to look for.
There are certain conditions to look out for when conducting an inspection that require the crane hook to be immediately removed from service. These include:
Hook deformation is when there are visible bends or twists on the hook. Cracks or sharp edges that could potentially sever the synthetic slings are another sign of deformation. This problem indicates that the hook has been subject to side loading, overloading, or improper rigging techniques.
Another deformity to watch out for during your hook inspection concerns the throat opening. Measure it to ensure that it is no more than one-quarter or 5% from its original dimension as laid out in the manufacturer’s handbook.
Nicks and gouges
Nicks and gouges refer to grooves, holes, or indentations found during the crane hook inspection. If you come across any nick or gouge that you can fit your fingernail into, remove the hook immediately from service.
Wear and corrosion
Crane hooks are subject to the same general wear and tear as other metals if improperly maintained. If you discover any wear that exceeds 10% of the original dimension of the hook, remove it from service. The same should be done if the load pin is also subject to this level of wear.
Check for any modifications to the hook surface. This includes modifications because of unauthorised grinding, welding, or drilling. If you notice any modifications to the surface of the hook, remove the hook and its hoist and schedule a replacement or repair before operating it again.
Bolts and pins
Bolts and pins keep the hook operable and in solid working condition. Ensure all bolts and pins in the hook are present and secure. Manually check the pin to guarantee it is properly connected to the hook block. The hook block is an assembly attached to the crane hook that usually consists of a steel enclosure that carries the ropes or chains necessary for the lifting of loads. Also, make sure that the hook can rotate and swivel freely when not under load. This helps determine whether there is any rust or corrosion on the bolts or pins preventing free movement.
Other factors to look for when inspecting hooks.
Some other things to look out for when conducting a hook inspection include:
- Presence of latches.
- The condition of bolts and pins.
- Field modifications affecting the integrity of the hook.
- Evidence of heat exposure or unauthorised welding.
- Manufacturing flaws undiscovered at the time of installation.
- Any other deficiencies constituting a safety hazard.
- Missing or illegible hook manufacturer’s identification.
- Missing or illegible rated load identification.
- Thread wear, damage, or corrosion.
- Where problems such as these occur, consult the opinion of a qualified professional.
It is also worth noting that crane hooks are subject to fatigue failure. This is caused by the stress level, load, and life count of lifting cycles. It occurs when the crane hook is used for overloads, heavy process-duty applications, old equipment and in conjunction with below-the-hook lifting devices. This usually results in a fatigue crack in the hook shank which leads to fatigue failure and the hook’s inoperability.
Since fatigue failure happens instantaneously, it is hard to predict it in advance. In addition, the hook is not accessible via visual inspection and requires the disassembling of the crane hook to be noticed. However, if your hook presides over near-capacity loads and has a high cycle count, then it is likely to exhaust its use period quickly. Where fatigue failure occurs, install a new crane hook immediately.
Hook latches are designed to support crane hooks in keeping rigging and loads in the hook when in a slack position. Under no circumstances are they to be used to support heavier loads.
Hook latches are required unless they create hazardous conditions. An example of when not to install a hook latch is if you must climb on a load to release the latch. Checking these latches is vital to crane hook inspection requirements as it guarantees loads are secured when being maneuvered.
Ensure that the latch bridges the throat of the hook when in a closed position and that it locks loads in place. Manually check that any self-locking hooks are working efficiently. If there is a visual gap between the throat opening and the latch, this is a sign of damage and requires remedying.