Cranes are tremendously powerful pieces of equipment that make it possible to lift heavy loads on construction sites. However, cranes are also potential hazards, as both cranes themselves and the loads they carry can cause harm when improperly handled.
From 2011 to 2017, the Bureau of Labor Statistics reported 297 deaths involving cranes. Of those deaths, more than half were the result of workers being struck by objects or equipment, and over 20 percent involved the crane operator. These statistics highlight the need for crane safety at all stages of operation, including travel, setup, rigging and lifting.
Below, learn 11 crane safety tips, including information about:
- Guidelines for crane travel
- Reminders about crane set up
- Tips for crane rigging
- Suggestions for safe lifting
1. Select the right crane for the job
Ensuring safe crane operation begins with choosing the correct crane. Cranes are either mobile or fixed, with fixed cranes generally being used in industrial settings or in complex or tall construction projects.
Mobile cranes come in many varieties, so make sure to select the right crane for the particular site.
- Carry deck crane: These highly mobile cranes feature easy setup and rotation, but they don’t handle rough terrain well.
- Crawler crane: They use tracks instead of rubber wheels making crawler cranes excellent for sites with soft terrain.
- Rough-terrain crane: Although these cranes cannot travel on public roads, they can handle difficult grades and tough terrain well on the job site.
- All-terrain crane: These versatile cranes have the advantage of being able to travel on their own to job sites and handle rough terrain once they arrive.
2. Always utilize qualified personnel
Safe operation of cranes demands trained personnel for setting up, rigging, signaling and operation. The Occupational Safety and Health Administration (OSHA) has regulations in place that require only trained, certified and properly evaluated individuals to operate cranes on job sites. Make sure to adhere to all regulations to be certain that qualified personnel are being used to operate cranes at all times.
3. Read operator manuals
Even when employing qualified personnel, it’s important to remember that cranes from different manufacturers have unique controls, failsafe devices and features. Anyone operating or working with cranes should have a detailed understanding of the specific crane being used. The operator’s manual includes vital information about:
- Load capacities
- Safety mechanisms
- Stabilizers and counterweights
- Operator controls
Be sure to read the operator’s manual in full before operating any crane.
4. Perform daily operator checks
A crane operator must use a daily inspection checklist to ensure the crane is safe prior to operation. These checks include pre-start checks, engine start-up checks and safety system checks.
- Pre-start checks: Before starting the crane, the operator should check tire condition, oil levels, seat belts, air reservoir and the battery, among other things.
- Engine start-up checks: Before daily work begins, the operator should start the engine, check the pressure gauge, fuel level, turn signals, horn, suspension and brain system, among other things.
- Safety system checks: Most importantly, safety system checks should be performed to prevent catastrophic accidents. Make sure to evaluate the anti-two block, the rated capacity limiter and outriggers.
Additionally, operators will perform a series of hydraulic system checks. Please consult your site’s daily operator checklist for a specific list of tasks.
5. Avoid or clear obstacles during travel
Prior to crane travel, it’s essential that a path is planned and cleared of all obstacles. Hazards that can’t be moved, like power lines or other permanent features, should be avoided and the operator should keep a safe distance at all times. For instance, regulations require that cranes stay at least 10 feet away from power lines up to 50,000 volts.
A signal person should always lead the crane during travel, making sure to alert the crane operator to potential hazards and also to warn other site personnel about the crane’s movement.
6. Carefully stabilize crane before rigging
Mobile cranes use outriggers or other stabilizing features to prevent the crane from tipping over during operation. When stabilizing the crane, keep the following in mind:
- Follow manufacturer guidelines to determine how far to extend outriggers.
- Always use outrigger pads or crane pads underneath outriggers.
- Never place outriggers over voids, depressions or unsteady ground.
Many crane accidents and tip-overs occur due to improper outrigger set up, so be certain that you’ve made a solid safety assessment of outrigger placement.
7. Rig the load correctly
Proper rigging of loads prevents objects from falling and potentially striking workers on the site. When rigging a load, take note of the following considerations:
- Hitching: It’s possible to attach slings to a load in a variety of ways, so consider the object being lifted as well as the weight distribution of the object. Basket hitching and choker hitching are two of the most common hitch configurations.
- Sling angle: Whenever an angle other than vertical is used, additional forces are induced on the slings, reducing their overall weight capacity. Make sure to use slings that are properly rated not only for the weight but also for the weight at a particular angle.
A complete understanding of force, weight distributions and rigging techniques will ensure a safe, stable lift of even the most irregular and heavy loads.
8. Understand load radius
In order to safely operate a crane, it’s vital to understand how a crane works and what forces are working against it. One of the most important concepts to understand is load radius, which essentially states that the further away the load is from the center of the crane, the less weight the crane can manage without tipping over or collapsing.
Load radius is affected by the angle of the boom as well as the length of any extensions on a telescopic crane. When the angle of the boom is higher (pointed more toward the sky), the load is closer to the crane’s center line and the boom can carry more weight. When the angle of the boom is lower (closer to level with the ground), the load is further from the center line and the boom can hold less weight.
9. Pay attention to load limits
Although many modern cranes include load moment indicators and rated capacity limiters, crane operators should still know how to read load charts in order to prepare for a safe lift. When reading load charts to determine if a lift is safe, keep the following in mind:
- On rubber vs. outriggers: A crane can hold much more weight when it’s on outriggers rather than on tires alone, and the load chart has different columns to represent this.
- Rotation: A crane can hold more weight if the boom stays over the front of the crane throughout the lift, whereas capacity is much lower if the boom will need to swing, so make sure to look at the correct column.
- Load radius: The higher the load radius, the less weight the crane can lift. Load charts typically don’t cover every possible radius, so always refer to the next highest radius to ensure that you stay within safe limits.
Load charts are the most essential tool for planning a safe lift and preventing crane failure or tip over.
10. Use proper communication and hand signals
A standard set of hand signals and communication protocols exists in order to facilitate safe operation of cranes. A qualified signal person is able to effectively communicate information throughout the lift to a crane operator, who can therefore adapt to changes in the lift situation as they occur.
Learning the standard hand signals will enable you to communicate the following to a crane operator:
- Which direction to travel with the crane
- When to swing and lift the boom
- When to hoist and lower the load
- When to stop the crane
In addition to hand signals, radios are also used during crane operation to ensure constant communication.
11. Manage complex lifts
Complex lifts are any lifts that involve loads greater than 80 percent of crane capacity — or greater than 50 percent of crane capacity for lifts on barges. It’s imperative to have a complex lift plan in place for any such scenario, as these present the highest risk for tip-overs or equipment failure. Develop a comprehensive plan, follow it closely and monitor the situation for any necessary adjustments during the lift.