How to protect your barn and horses from lightning.
Lightning is nature’s energy unleashed. We might only see a lightning bolt for a split second, but what takes place is an immense discharge of electricity aiming to find the shortest and easiest path from the clouds to the ground.
A typical lightning flash is four-tenths of a second long and generates about 25,000 amperes (an ampere measures the rate of electron flow per second past any point in a wire); 30,000,000 volts (voltage measures the force that makes the electrons flow); and has temperatures of from 30,000°F to 50,000°F. In comparison, house current is 110 or 220 volts and most people set their thermostats at around 70°F.
Protecting Your Barns
Lightning strikes a barn because the materials in it are better conductors than air. The Lightning Protection Institute notes that nine out of ten barns struck by lightning burn to the ground and are total losses – and it happens very, very fast. One owner saw lightning strike the metal roof on his bank barn, raising it up, and flames immediately erupted in the upper level. All the horses in the lower level were found dead from the lightning strike, and it all happened so fast that in the minute or two it took him to gather his wits and call the fire department, there was nothing left to save.
Components Of A Lightning Protection System
Lightning protection systems are designed and installed to protect all the points where a lightning bolt would most likely strike, and all objects to which the current might “side flash” (where it might jump from one object to another).
• The part of the system most easily recognized is the air terminal or lightning rod. These are pointed metal rods, usually copper or aluminum, installed on a building’s high points. On a barn, this is commonly the roof ridge. How many terminals are needed depends on the length of the barn.
• Down conductors, also known as main conductors, are heavy braided copper cables that connect the air terminals with each other and with the grounds. Their job is to conduct a lightning bolt from a struck terminal to the ground, and to do that, each down conductor requires its own ground.
• Secondary conductors connect metal parts of a building together to keep it from jumping across the gap between them. All secondary conductors are connected to the main conductors. We may have more metal in our barns than we realize. Some of the things to be protected, besides a metal roof, may be stall door tracks, water lines, and possibly the stalls themselves if they have metal components.
• Arresters protect a building’s wiring system from electrical surges entering through phone or electric lines because ordinary circuit breakers can’t handle the massive power surge caused by lightning. Arresters are installed at the fuse box or breaker panel and are connected to the lightning protection grounds.
• The ground connections cause lightning charges to dissipate into the ground without causing harm. Ground rods, usually made of copper, are driven ten feet deep and set at least two feet from the foundation.
Your Installation Checklist
Installation of a lightning protection system must be done by a professional because there are too many components, each needing to be tied in correctly to the others, for the job to be done by anyone but an expert. The Lightning Protection Institute recommends you follow these steps when considering installers:
- Check and record the salesperson’s identification and verify that he is connected with a lightning protection company that has bank references and is registered with a Chamber of Commerce or the Better Business Bureau.
- Get customer references and verify them.
- Make sure, before work commences, that the company or individual carries Workers’ Compensation insurance.
- Check with the Lightning Protection Institute to determine if the installer is an Associate Member. It is not a mandatory membership, but does indicate a responsible installer. They have a list of member installers on their website so you can easily locate one in your area.
- Insist on a contract that lists all the parts necessary for an Underwriters Laboratories (U/L) installation.
- Check to see that every component – rods, ground rods, connectors – carry a U/L label and that arresters show the manufacturer’s name.
- Your installer must have you sign an application form for a U/L “Master Label” plate. This form will go in the mail directly to Underwriters Laboratories through the manufacturer of your equipment.
Following these suggestions is crucial; if any single part of a lightning protection system is not installed correctly and/or with the proper materials, the entire system can fail. Lightning is your horse’s worst enemy, inside the barn or out, so you can’t take any chances with the installation.
Protecting Your Horses Outdoors
Horses and cattle are particularly susceptible to being struck by lightning when they stand under a tree or other object that conducts lightning into the earth. This ground current radiates out from the tree or other struck object, and because horses and cattle have four legs, the electric current passes through major body organs while going from front to rear legs or vice versa.
Obviously, outdoor protection cannot be as precise as for your barn, but a number of protective devices can be installed:
- Special tree systems bring the lightning charge into the ground outside the root system, cutting the ground charge. Utility poles can also be protected by these systems.
- Protect water troughs by erecting two ground poles at either end of the area to support a ground wire over the area of the trough.
- Ground wire fences at 150-foot intervals or less so a lethal charge is confined to that span.
Lightning is unpredictable and can be devastatingly damaging. By ensuring you have proper protection systems in place, you will no longer have to fear for the safety of your farm or animals when summer storm clouds start rolling in!
Laurie Loveman is an author, fire department officer, and a member of the National Fire Protection Association (NFPA) technical committee on fire and life safety in animal housing facilities. She has a degree in fire and safety engineering technology from the University of Cincinnati and is a consultant on fire safety in equine facilities. With more than 40 years experience in the horse industry, Laurie has written many articles for equine and fire service publications, and her Firehouse Family novels, set in the 1930s, reflect her interest not just in horses, but in topics relevant to firefighting, such as stress, medical ethics and arson. firesafetyinbarns.com