The 3 Pillars of Crane Safety
Crane accidents are relatively rare but have devastating consequences. There's no room for error in your crane safety plan.
Cranes are indispensable for a number of different industries. But keeping everyone safe when you have something so large and powerful on your jobsite requires the utmost of care and a thoughtful, regulated approach.
According to the US Bureau of Labor Statistics, incidents involving cranes account for about 42 fatalities per year across the United States. That may not be a staggering number, but it is nevertheless high given that most crane accidents (or at least their more severe consequences) are entirely preventable.
While crane incidents are relatively rare, the consequences of one can be serious. They also make for eye-catching headlines and attract attention, whether you'd like them to or not.
In other words, it's in your best interest to do what it takes to avoid any mishaps involving a crane on your site.
Thankfully, there are a lot of helpful resources on safe crane use. Broadly speaking, all of the guidelines can be grouped under three categories. We'll discuss each of them in this article to give you an overview of what a complete crane safety program must include.
Cranes operate under substantial physical loads, which can influence the rate at which maintenance is required as well as the likelihood of component failure.
Although the equipment is engineered to “fail safe,” failures can nevertheless be unpredictable. Moreover, because we are dealing with suspended loads, there are some conditions that simply cannot be made to fail safe - conditions that have to be carefully mitigated.
Cranes rely on the coordination of various material components that will be put under massive mechanical stress. The failure of any of these components has the potential create a chain reaction that can upset or drop a load, cause a collapse, or result in other unintended outcomes. It is literally a case of a chain only being as strong as its weakest link, which is why you have to make sure no weak links are overlooked.
All slings, wire ropes, shackles, hooks, webbing, pins, and other lifting implements have to be inspected for deformation or deterioration (such as the presence of rust or mechanical wear) prior to use. The inspector will need to know what they are looking for and have the authority to condemn any materials they feel may be unsafe.
Take "bird caging," for example. It's a deterioration of the rotation-resistance wire rope that causes the wire to bulge and take on an appearance similar to a bird cage. It's a subtle but serious sign that the equipment should be discarded. Would you know to look for it?
The inspection and maintenance of the crane itself is vastly more complicated and requires the participation of someone trained in performing the work. All types of cranes should be inspected before each use (or at least daily) to ensure that the components are present, secure, free of damage, and operational.
The manufacturers of the crane itself and all other lifting implements will be able to provide you with a complex set of instructions for maintaining the equipment. These should be used as your basis for developing a maintenance plan. After all, who better to advise you on maintaining the equipment than the people who built it?
OSHA now requires that crane operators not only be trained on the use of the equipment, but trained on the specific type of crane they will be using. That's a sensible move since cranes come in many dissimilar varieties - tower, boom, picker truck, gantry, crawler, overhead, and even crane-like assemblies like pile drivers or derricks. No generic lifting training could cover all the requirements for every type of crane, not to mention the differences between types and brands within those categories.
It isn't only the crane operators who need training, however.
Basic rigging training should include how to configure a lift and how to select appropriate implements. Important details like sling angles have an impact (the more acute the angle between the load and sling, the greater the stress in the individual sling legs). Signalpersons need to be trained in the specific signals to be used and when to use them. They need to know where to stand and how to maintain contact with the operator. The site supervisor needs to be trained on planning the lift and securing areas underneath the planned route of travel.
For complicated or critical lifts (usually those that use at least 80% of the crane's load capacity), the input of engineers may be required (who, of course, have their own education and experience requirements). They may need to calculate how something may be lifted or how to include “lift points” on a manufactured piece of equipment so the item can be lifted straight up and supported without rotating, jostling, or failing. The lift points must also be connected securely enough to support the whole weight plus a safety margin.
Lift plans aren’t just for “critical lifts.” Every time a crane is used there are a number of factors that need to be considered:
- How much does the load weigh?
- What is the effect of wind?
- Is the ground level and stable enough to support outriggers?
- What obstructions are going to be in the path of the load or the crane itself?
- How closely can we place the crane to the load?
All of these will inform what equipment is appropriate and how the lift needs to be approached. If, for example, the layout of the site means the crane’s boom has to be extended all the way, the load capacity will go way down. Can it still perform the lift? Get the answer wrong, and the crane could tip under the load.
When a lift hasn’t been properly planned, it might result in multiple attempts at lifting or the crane operator having to reverse the process and place the load back down on the ground. All of these multiply the hazards involved and are to be avoided. All other things being equal, you'll want the load to be suspended as briefly as possible.
Part of planning is also making sure that the site is made safe prior to performing a lift. Not just for the crane, not just for the load, but for everyone at the site and in the vicinity. Walking under a suspended load is never permitted and the lift should not be performed under any conditions that would require it.
The site's conditions should also be evaluated. The ground must be level and stable for the outriggers. The swing zones must be kept clear. Taglines should be attached to the load and operated form a safe area. A line of sight from the operator to the signaler must be maintained. Is there a potential for explosive atmospheres? At a gas plant, for example, crane operations are considered "hot work" and therefore require grounding, atmospheric testing, spark watch, and all the other precautions.
There is a lot to consider in planning a lift, and once it's up in the air it's too late to realize some detail was overlooked. A well-trained lift supervisor will have a full checklist ready to ensure that all the important factors have been considered
(Learn more about Solutions and Precautions for Uneven Ground Conditions)
In most cases, it's possible to use cranes safely - it just isn't easy.
The use of cranes needs the support of a well-designed and administered lifting program and a series of trained individuals. With these resources in place, you can be assured that your cranes can operate safely. And that's critically important, because for many of the things a crane can do, there is simply no other way to go about it.