Copper is always part of the solution for marine lightning protection!

By Frank Ross

Sailboat masts and steel cranes are two things you don't want to be near during a lightning storm.

Sailboat masts and steel cranes are two things you don't want to be near during a lightning storm.

The thrill of plying through storm-tossed waves, driven by winds that keep canvas sails pulled taught can change from thrill to chill when the familiar crack of lightning illuminates the sky. Like many things in our lives, under the right circumstances a positive characteristic can transition from blessing to bane in a matter of minutes.

Sailing is a relaxing, and sometimes exhilarating experience, driven by the silent power of wind; but the nature of these boats is limited speed. When a storm blows in quickly you can’t outrun it. In fact, there isn’t much on the water that you can outrun in a sailboat. However, the real downside on the majority of boats under sail is the tall aluminum mast is basically a bobbing lightning rod. The mast is secured to the bow, stern and both sides by stainless steel cables. It that’s not enough to set your teeth on edge, stainless steel handrails surround the boat, you and your passengers. And, to further enhance your odds of illumination, if yours is the only sailboat in the area, your mast is definitely the tallest lightning rod for many square miles.

As you’re estimating the distance to safe harbor and making mental measurements of the approaching storm’s speed, you might consider the statistics and find comfort in the fact that BoatU.S. Insurance survey numbers indicate that for every 1,000 boats in the US, only 6 per year are hit by lightning. Then, when you recall that there are well over 150,000 sailboats in the US and you could become one of 900 to feel the jolt this year, you regret not having taken more precautions.

US Boat insures a lot of watercraft, and their experience with lightning damage is extensive. Their figures indicate that after single-hulled sailboats, multi-hull sailboats, such as catamarans and trimarans are the next most likely to suffer a lightning strike (.5% Five out of 1000), followed by trawlers (.3% Three out of 1000), sail only (.2% Two out of 1000), cruisers (.1% One out of 1000) and runabouts (.02% Two out of 10,000).

To make matters worse, these floating lightning rods are sitting in water which is an excellent conductor of electricity. Although you may reduce the odds of your boat being struck in a marina, surrounded by other masts, do you really want to take a chance. In a direct strike, lightning follows the path of least resistance to the best ground, blowing out fiberglass around watertight seals and sometimes large holes through the hull. Even boats without a tall mast are at risk if they are moored next to a sailboat or a tall pole used to supply power and lighting to the dock area. Lightning can blow out horizontally to a nearby grounding source and damage multiple boats with one strike. Following a severe lightning storm, boat owners often find they have a craft with extensive electrical damage, compounded by saltwater intrusion, sitting on the bottom of the bay. It’s a heartbreaking experience that a good marine lightning protection system could prevent.

In my younger days, I spent many a blissful day sailing with an old salt who worked as a radio engineer to support his sailing habit. He maintained several radio and television towers, located in the bay area just East of Tampa, Florida; an area that is often referred to as the lightning capital of the North America. Each year, Florida averages 10 deaths and 30 injuries, with many of them occurring in the Tampa Bay area.

With his professional background and all of this exposure to lightning, Warren’s philosophy both on and off the water was absolute; never take chances. He had an elaborate system for grounding his mast to his lead keel and disconnecting his electronics when skies threatened. But his best rule was don’t hesitate, get off the water at the first sign of bad weather. Dockside, his marina lightning protection system was two heavy grounding wires that ran from a grounding post on the mast, into the water on both sides of his boat. Inside the cabin, he always disconnected everything electrical, including the connections to the engine compartment. Although his “iron sail” was diesel powered, there is always the danger of fire in a direct strike, and even more so with gasoline engines.

If you love to sail and have been considering the proper way to protect your investment, an article in Seaworthy, a magazine published on the BoatU.S. Web site should be of interest. It discusses all of the issues involved in building a good marine lightning protection system.

Once you’ve read the article, Understanding Lightning Protection, you’ll notice that copper grounding bars and wiring are recommended throughout. Get your plan together and give the helpful staff at Storm Copper a call at 1-866-716-9773, or log onto their Web site for a complete listing of everything necessary for building a first class copper grounding system.

With a quality copper lightning protection system installed in your boat, you’ll not only feel safer on the water, you’ll be safer.

Just remember Warren’s No. 1 rule. When you see a storm on the horizon, don’t hesitate ~ RUN!

By Frank Ross

rods

The classic Franklin point design, and the more blunted version of modern lightning rods.

In any lightning protection system, the soldier manning the front line is the air terminal. This simple component is engineered to intercept the downward-moving stepped leader by launching an upward-reaching attachment spark that will serve to close the circuit and direct the flow of current to a solid grounding device, away from a structure and expensive electronics.

Even if you’ve never seen an air terminal in person, more than likely you’ve seen pictures of them on tall buildings, barns, and homes. Most likely the end of the air terminal you’ve seen was very sharply pointed. The theory behind the sharp point design is that it causes the largest electric field and hence is more likely to launch the attachment spark. Sharp pointed air terminals, originally designed by Ben Franklin are a time-honored concept; however, recent research has revealed that blunt rods are slightly more effective in accomplishing this job.

Since Franklin’s initial invention in 1749, there has been controversy between American supporters of Franklin’s design and British scientists that insist the rod should have a round ball on the end. In recent years there has been a great deal of research with far more sophisticated monitoring and measuring equipment which actually proves neither was correct.

Perhaps it was the politically charged atmosphere between the British and the Americans during the early days of this country’s development that caused Franklin and other American supporters to stand doggedly behind his pointed design, but more than likely it was the limited tools at his disposal for accurately analyzing the effectiveness of either. Remember the kite and key experiment? That came about because of repeated delays in the construction of a church steeple that was to utilize one of his lightning rods. Regardless of the choice, neither kite nor distant observations of a church steeple would have provided much more than anecdotal evidence.

Many modern physicists have shown that, under strong electric fields, the air around sharp rods becomes ionized. This ionized air creates space charges that act to weaken the fields of electricity building up and flowing from ground to components atop roofs, towers and similarly susceptible structures. In both laboratory and field experiments scientists have established that critical field strengths for lightning interception develop more quickly around moderately blunt or blunt lightning rods that those with sharp points.

The most effective air terminal is one with a radius of curvature between 3/16 and 1/2 inch. This is not to say that pointed terminals should be avoided or replaced. They are effective, but moderately blunt or blunt terminals are just more effective.

I’ll get more into components and other aspects of a lightning protection system, to give you a general understanding of how these components make up a protection system and how that system works; however, you should always seek the advice of an engineering specialist with specific knowledge of lightning protection.

In the meantime, Storm Grounding has a complete line of top quality rods, mounting brackets, grounding cables and grounding rods viewable at Stormgrounding.com.

Other links of importance:
United Laboratories Installation Guidelines

Residential Lightning Protection and Grounding

Arborist (Tree-Top) Lightning Protection and Grounding

Barn and Outdoor Structure Lightning Protection and Grounding

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