Electroshock Drowning – Prevention

Electroshock Drowning, Prevention. A few days ago I received and enquiry on my Facebook page (thanks Brian) asking about the possibility of testing for stray electrical current leakage in the water at marinas. To that end I thought that I’d talk that very subject in this post.  To make a long story relatively short it is possible to test for this but to do so requires specialized equipment. You basically need a Digital Multi Meter which is very sensitive on the low side of AC amps scale and it needs to be equipped with precious metal test leads.

Unfortunately these test results are  only good at the time of the test. In other words you could be ok  today and not tomorrow Unless you are testing every day or so which is probably not going to happen.

In my opinion,  prevention is  much better and a more practical solution to the problem than trying to continually monitor for any stray current leakage. The good news is that it’s not difficult to do just that. There is a devise on the market which is easily retrofitted to just about any boat’s on board  shore power AC electrical system. It’s called an Electrical Leakage Circuit Interrupter or  ELCI . It’s simply a high capacity Ground Fault Interrupter (GFCI) which breaks the circuit if it senses stray current leakage to ground or in our case into the water. You all know what a GFCI is. It’s that AC plug installed in our kitchens and bathrooms in our home that have the little red and black push buttons in the center. If the red button pops you simply press the black button to reset the devise. If it continually trips then you obviously have a problem which needs to be corrected.

To understand how these devises function we need to go back to our basic electrical theory which states that on a properly functioning AC (alternating current) circuit there should be equal current flow on both the hot (black) and the neutral (white) wires. Any current leakage on the circuit, however small will cause an imbalance in this current flow and the ELCI will automatically open and break the circuit.

The main difference between the ELCI and the GFCI are the current levels at which they trip at. The GFCI trips at 5 milliamps which is really too low for to be any use to us and  the ELCI trips at 30 milliamps. Enough to serve our purposes but not enough to be harmful. (Remember .6 amps AC = heart failure). The reason  that GFCI’s are ineffective for this is that all boats plugged into shore power on any one dock are electrically connected through the shore power grounding circuits and properly functioning boats will usually leak small amounts of current into the water, even under normal conditions. In most cases these current levels are too small to be of any concern. The problem is that they are cumulative (they add up) and can increase to levels, that while are still not dangerous can cause nuisance tripping of the GFCI’s and be a real pain.  This is also why, in North America AC power services at the docks rarely have GFCI’s installed. I understand that in other parts of the world GFCI’s are sometimes utilized on docks.

Ok back to the ELCI. Installation is relatively simple. In many cases the main 2 pole circuit breaker at the AC main panel can simply be replaced with one that incorporates the ELCI into it. Otherwise they can be installed as a stand-alone in the main AC feed circuit between the vessel shore power receptacle  and the 2 pole main circuit breaker at the on board  AC panel. They also are not costly, average  about $2-300 USD. Additional  information on the ELCI can be found at www.bluesea.com

In addition to the installation of the ELCI it is recommended that the on AC and DC grounding circuits be connected aboard the boat. This is easily done right at the panel.

New EBook “A Guide to Sailboats and Their Systems”

I’ve just published my first EBook. “A Guide to Sailboats and Their Systems”

ebook guide to sailboatsEach year in my profession as a marine surveyor I get involved in a number of pleasure craft pre-purchase situations. Many of these involve first time boat buyers who, while they may have considerable sailing experience either with friends or chartering will often find themselves with little or no practical knowledge about the mechanical aspects of the boats that they wind up purchasing or how the onboard systems operate. As such I am often called upon to explain and demonstrate how these on board systems and devises operate.

That’s what this book is intended to do, provide both new and seasoned boat owners with some insight as to how various on board systems function and hopefully address some of the common questions that do arise. Whether it’s a safety related issue as to “Why is there a polarity indicator on my shore power panel?” or “What does the pressure gauge on my propane supply regulator do?” I’ve tried to answer them all and hopefully provide boat owners with some valuable insight as to how their on board systems function.

I’ve also included discussions on sail design and construction, an explanation of the different types of sailboat rig configurations and some good information on the basics of fiberglass hull and deck construction. There’s also a chapter on auxiliary power and the necessary systems that allow our on-board engines to function.

The intention here is to present a detailed overview to both rookie and seasoned sailors on how sailboats and their systems function.

So whether you are a new or seasoned sailor or are you just moving up to a larger more complex boat I hope that as a reader you find some interesting information here.

Available at all leading EBook retailers including

 https://www.smashwords.com

http://www.amazon.ca

http://www.barnesandnoble.com

Safe Liquid Propane Gas (LPG) Installations

In this post we are going to take a look at what constitutes a proper and safe Marine LPG (Liquefied Propane Gas) installation. As a surveyor I encounter many improper and unsafe LPG installations and to be truthful very few proper ones. When you consider the fact that this stuff has the ability to cause fatal injuries or completely destroy your vessel serious attention needs to be paid to these installations. LPG on sailboats is used mainly for cooking and cabin heat but occasionally it is also utilized in refrigeration and hot water heating systems. It is manufactured as a by-product of natural gas production and gasoline refinement. At atmospheric pressure it is in a gaseous state but under moderate pressure it becomes a liquid making it easy to store and transport. It also naturally odorless but the strong pungent smell related to propane is the result of a chemical added to facilitate leak detection.
LPG Marine Tank
The downside to propane gas is that it is highly flammable and being heavier than air it collects easily in the bottom of any enclosed area such has boat cabins and bilges. It is for these reasons that it needs to be handled and treated carefully. The ABYC (American Boat and Yacht Council) has a long list of standards pertaining to marine LPG installations and we’ll take a look at those next. Here’s the condensed version.
1. All LPG storage tanks, shut off valves, pressure gauges and regulating equipment should be ignition protected, secured for sea conditions and enclosed in a dedicated, sealed locker with a gasketed lid equipped with a mechanical latch. Nothing else should be stored in this locker. It should be situated above the hull waterline and vented out the bottom to flow overboard.
2. The gas supply line should be of approved hose and have a pressure gauge installed between the tank and pressure regulator / line shut off valve to facilitate leak testing of the system. To do this you simply open the tank valve (with the line valve in the “on” position), then close the valve and watch the gauge. If a leak does exist the gauge pressure will drop. The system should hold pressure for at least three minutes. The line shutoff valve mentioned above can be manual but is usually an electric solenoid installed at the pressure regulator with the on / off switch being located within easy reach of the appliance without reaching over the appliance. The only time that this devise is not required is if the tank valve itself is within easy reach of the appliance.
3. All feed line splits (to facilitate multiple appliances) should be located inside the storage locker itself and a separate line be run to each appliance.
4. Where the feed line(s) exit the tank storage locker there should be an air tight seal between each line and the locker wall.
5. An LPG leak detection system should be installed in the vessel’s living quarters.
Just in case you think that these standards are overkill let me share with you a story told to me about a year ago by an ABYC training instructor at a course I attended. There was a reported case of a late model 36 foot sailboat anchored on an inland lake in the US. It was a cool evening and the vessel’s full cockpit enclosure was in place. The boat had an LPG installation that met all of the standards listed above with one exception. The tank storage locker did not have a sealed lid, meaning that no gasket was installed and there was no latch. A leak developed at the pressure gauge and a considerable amount of LPG gas made its way from the locker, through the cockpit and into the main saloon. The operator noticing the smell immediately switched on the cabin lights one of which had a loose wiring connection causing a spark and igniting the gas. Amazingly enough he wasn’t hurt but did hear a loud “Whump”. He then went up on deck only to find that the entire hull to deck joint had separated and the deck was literally “ballooned” upward. So you can see this stuff really needs o be treated with respect.
I also want to comment on another issue I frequently encounter with regards to LPG installations. This is all of the small tanks I see strapped to stern rails and flexible hoses connected to portable barbecues. These installations literally don’t meet any of the standards I’ve listed above. The tanks generally are not secure and there is no way to leak test the systems. While the chances of gas migration into the vessel’s living areas may be reduced there’s nothing preventing a leak from setting body parts or your skivvies on fire when you light the appliance. Be careful!
So you can see that while LPG, as a cooking or heating fuel can make our cruising lives much easier it can also be very dangerous if not handled properly. Refer to the above list and ensure that your installation meets all of the criteria I’ve noted. If you’re unsure of any of this I suggest that you contact a knowledgeable professional and have your system inspected. Any ABYC Standards certified marine surveyor or technician should be glad to assist you.

Kidde Recalls Disposable Plastic Fire Extinguishers Due to Failure to Discharge

I just received this in my email so I thought that I’d pass it along.

Here’s the link: http://www.cpsc.gov/en/Recalls/2015/Kidde-Recalls-Disposable-Plastic-Fire-Extinguishers/

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