We sure have seen our share of storms lately and know many areas of the country have as well. In Florida, there are crazy afternoon thunderstorms that pop up out of nowhere and at times can be quite scary due to the amount of lightning that comes with them. Recently one of our customers asked “Where can I find the guidelines for lightning safety with cranes?” Unfortunately, lightning is not addressed in a straightforward way that Crane Tech wishes it was. There is no formal set of guidelines in the U.S. for crane usage around lightning, except where it is mentioned in several standards as a part of adverse weather conditions. In most cases the standards either refer to the manufacturers recommendations to secure the crane at the crane operators/qualified persons discretion, etc.
It has been reported that if a lightning strike is detected 10 miles away, then the next strike can be at your location—regardless if it is raining or not. Since lightning is unpredictable, how do you know if lightning is within striking distance and work should stop?
This is where many times the push and pull of risk versus cost begins. The question gets asked, “do we stop work for the sake of safety at the expense of the project timeline and budget?” So before Crane Tech provides some recommendations regarding cranes and lightning, lets ask this simple question: If lighting was striking near by, would you continue to:
- Sit in a steel boat with a fishing pole in your hands just to keep fishing?
- Swing a metal golf club in order to play your full round of golf?
- Push the metal lawn mower just to get the grass cut?
Chances are you said “NO” to each of these, as common sense tells us that these are all fool-hardy options—if you were to do these things in an approaching storm, you are just asking for trouble. The same could be said when operating a crane near lightning. Simply put when a crane boom is stuck up in the air, it acts like a lightning rod. So common sense must prevail in this case as well.
So when do you cease work, where do you go, and for how long should crane operations be suspended? While the first strike of lightning or the exact location where lightning will strike next cannot be predicted, it is easy to tell if lightning is in the area. There are inexpensive portable lightning detectors on the market that can detect when there is a strike within a 10 mile radius, many smart phones also offer weather apps that can notify the user of lightning, or there are commercial lightning detection systems that monitor and notify of lightning activity. Another way is in terms of thunder, which is created when lightning’s high temperature explodes the surrounding air. If you can hear thunder then you are close enough to be struck by lightning. In other words from the National Lightning Safety Institute, “If you can see it (Lightning), flee it; If you can hear it (Thunder), clear it.”
Crane Tech recommends that employers and supervisors follow these best practices for working with cranes, modified from OSHA and NOAA guidelines for workers whose jobs involve working outdoors:
- Check NOAA Weather Reports – prior to and during any work that may be impacted my hazardous weather conditions. Watch for darkening clouds and increased wind speeds, which can indicate developing thunderstorms, and take action after hearing thunder/seeing lightning.
- Shut the Crane Down – land the load, lower the boom, shut off all electrical power, secure and leave the crane.
- Seek Shelter – go to a safe structure and remain in the shelter for at least 30 minutes after hearing the last sound of thunder. The preferred shelter is a fully enclosed building with electrical wiring and plumbing—small rain/sun shelters and gazebos are not considered a safe structure. If a permanent building is not accessible, workers should use hard-topped metal vehicles with rolled up windows.
- Avoid hazardous objects/areas – Move away from any metal objects including fences, machinery and electrical equipment. Avoid solitary trees and open fields. Do not stand in water and do not use the telephone or touch appliances (portable radios and cell phones are safe to use).
After the recommended 30 minutes or when it is safe for operations to resume, do a thorough pre-use inspection of the equipment again to check for damage. According to several crane manufacturers they refer to lightning strikes being the cause of problems with the electronic systems that control crane functions. If the LMI is not working or there seem to be other concerns that did not exist before, then lightning may have impacted the crane.
In ALL instances, refer to the manufacturer’s recommendations prior to re-starting work. An excerpt from a crane operator manuals states: “An extreme form of heat damage is caused by lightning strike. The rope may heat up at the point of the strike to such an extent that the steel starts to melt. In all cases of exposure to high temperatures, the rope must be changed regardless of whether or not wire breaks have occurred.”
While it may be hard to remember while you are waiting on a storm to pass through, one of the key things an employer can do is create a safe working environment by establishing and adhering to guidelines in order to keep workers safe.
For more information on this topic, consult the recently updated OSHA and NOAA Fact Sheet: Lightning Safety When Working Outdoors. Have a topic you’d like more insight on? Let us know—comment below or Email us. You never know what Crane Tech’s take might be.
P.S. According to the Standards
Want to review the standards yourself? Here are the excerpts from various applicable standards. We find it shocking how little direction is given on this very important topic!
OSHA Subpart CC
- OSHA Subpart CC – Consideration was given to the possibility of dangers with lightning strike around power lines that are not visibly grounded.
- 1431 Hoisting Personnel – (k)(8)(ii) Other weather and environmental conditions. A qualified person must determine if, in light of indications of dangerous weather conditions, or other impending or existing danger, it is not safe to lift personnel. If it is not, the lifting operation must not begin (or, if already in progress, must be terminated).
- Appendix C – Technical Knowledge Criteria – (c)(6) Know how to apply the manufacturer’s specifications for operating in various weather conditions, and understand how environmental conditions affect the safe operation of the equipment.
- 22.214.171.124(x)(6) – considering the recommendations of the manufacturer for securing the crane, when a local weather storm warning exists.
- 5-2.9 – The plan should address, at a minimum, the following potential events that could cause a deviation from the lift plan: (b) Adverse changes to environmental conditions (e.g. weather, visibility)
US NAVY NAVFAC P-307
- 8.2.3 Lift Safety – For other weather and environmental conditions, the supervisor shall determine if, in light of existing or impending hazardous conditions, it is safe to perform, or continue with, the lift. If it is not, the lifting operation shall not begin (if already in progress, the lift shall be terminated).
- 9 Adverse Operating Conditions – When an operator observes an adverse operating condition, he/she shall suspend operations and notify the supervisor for resolution. An adverse operating condition may result from climatic conditions (snow, ice, wind, rain, lightning, etc.),
- 9.1 – When severe adverse weather conditions (snow, ice, wind, rain, lightning, etc.) have the potential to develop, actions shall be taken to preclude damage to weight handling equipment or other property
US Air Force AFOSH STD 91-46
- 2.3.6. – During periods of non-use, high winds, or weather alerts, the operator will lower the boom to ground level or to a resting platform or otherwise ensure the boom is secure against displacement from wind loads or other outside forces.
American Petroleum Institute API RP2D
- 3.1.3a – During periods of bad weather, such as lightning or high winds, or where the Crane Operator’s ability to see the signal person is impaired by darkness, fog, rain, etc., crane operations should be restricted, at the Crane Operator’s discretion.
Many thanks to Krookid Photography for use of their crane and lightning photo!