EXPLOSIVE NEWS

It's two-thirty on a warm August afternoon. The operator of a new 27 foot express cruiser, with three passengers aboard, has just finished fueling, loading 80 gallons of gasoline into his tanks. He closes the tank fill, and runs his bilge blowers for four minutes. The gasoline smell lingers, but he's sure it must be from the tank vents and the fuel dock. He starts to turn the key, hesitates a second, and fires up the engine.

Later, from the burn ward at the trauma center, he says he never heard or saw the explosion that threw him into the water, killed one of his passengers, and severely injured the other two. Nor did he see the ensuing fire that destroyed his boat and damaged the fuel dock and two adjacent vessels. "What went wrong?", he asks. "I ran the blowers like I should and still the boat exploded."

This captain broke the cardinal rule of safety on gasoline fueled boats. He didn't lift the hatches, look and sniff, to be sure that fuel hadn't leaked into the bilge. In his case, a loose clamp on the single clamped fuel fill, had allowed several gallons of gas to run into the bilge, where it vaporized and ignited when the engine was started.

Gasoline is strange stuff. A mixture of aliphatic hydrocarbons, it has a flash point of minus 50 degrees Fahrenheit (-50F). So, even in the coldest temperatures, it'll still burn. It's vapor density is three to four times that of air, which is why fumes find the lowest point of your boat, the bilge. It has a lower explosive level of 1.3% and an upper explosive level of 6%, meaning that when mixed with plain old air (vaporized), anywhere between those percentages, and given an ignition source, it's gonna blow. Autoignition temperature is 536 F to 853 F, so if you heat it up on a hot manifold, poof!

So, what can you do to reduce the potential for an explosion and fire? There are a few ways. First, before you start those engines, or generator, raise the hatches, get down below and take a good sniff. There should be no odor of gasoline in a properly maintained vessel. Second, regularly check all fuel system hoses and clamps. All fill line fittings should be double clamped at the tank and deck fitting. Vent hoses should be double clamped at both ends. Damaged hoses should be replaced immediately. Third, be sure your blowers are adequate, properly connected, and draw air from the lowest points of the bilge to exhaust any possible vapors. Finally, consider investing in a vapor detector or "sniffer" for your bilge. They're invaluable sentries when you're underway, and can't sniff the bilge for yourself.

My personal story had a much happier ending than the one above. Returning to the dock after an afternoon cruise on my sportfisherman, I climbed down from the flybridge to the main deck, where I smelled the strong odor of gasoline. I thought one of my neighboring boaters was filling an outboard tank, but this was even stronger. The odors seemed to be coming from my bilge. I opened the hatch to find the port tank had ruptured, and the bilge awash in gasoline. I won't bore you with the cleanup details, nor the precautions we took to preclude ignition, but there were many. The important thing is that there was no explosion or fire. I always run with the ventilation blowers on. I feel it provides an extra margin of safety, and in this case, the blowers likely kept the vapors minimized until the engine was shut down, and all electrical circuits de-energized. Cheap insurance, replacing a blower every two or three years.

Explosion and fire is a terrifying ordeal on shore, more so aboard. Protect your vessel, and your life, by practicing safe fueling, ventilation, and fuel system maintenance.

Safe Boating.

WHAT"S COOKIN', GOOD LOOKIN'?

Well, many of you will want to know what makes me an expert on cooking safety. I don't cook much, still have all my fingers, some of my hair, and haven't burned up my boat, so I'm at least one up on a few boaters in Southern California. But, seriously, cooking accidents are especially dangerous aboard a boat, and a few precautions can reduce the risk to you and your boat.

Alcohol Stoves:
NEVER fill a hot stove. On a pressurized stove, let the stove cool before bleeding off pressure and filling. On a cartridge or canister type stove, let the canister cool before filling, and ALWAYS remove the canister from the stove before filling. Remove extra alcohol from the area where you are cooking. Keep spare fuel tightly capped, and stowed where the container will not rust through. Wipe up spilled fuel immediately. And, keep a small spray bottle filled with water near the stove. A fine mist will tame alcohol flare ups, and repeated mist sprays will usually extinguish a small cooking fire. DO NOT use a straight stream; this will only spread the burning alcohol, or grease, to other areas.

LPG & CNG:
If you use liquid propane gas (LPG) or compressed natural gas (CNG), check the appliances and all supply lines regularly for leakage. Be sure regulators and solenoids, if equipped, are working properly. If you use LPG, the preferred tank location is above decks, away from openings where escaping vapors could enter the enclosed spaces of your vessel. If your tank is in an enclosure, designed for LPG storage, be sure the vents are free of blockage and there are no openings that will allow gas to seep into the bilge. Check the tanks frequently. If a tank is damaged, or severely rusted or corroded, replace it. With CNG, refuse to accept exchange tanks that are damaged or deteriorated. And, shut off the supply at the tank when the system is not in use.Consider installing a gas vapor detector in the engine and bilge spaces of the boat if you use LPG. Vapors are heavier than air, and a leak can go undetected, while filling your bilge and engine spaces with explosive vapors.

Barbecues:
If you have a gas barbecue on board, the type that uses the small disposable cylinders, store the cylinders above decks, and take the same precautions you would with larger tanks. These cylinders, containing sixteen to twenty ounces of LPG, can put enough gas vapor in your boat to destroy it at the slightest spark. At least one of the manufacturers has a storage bag that attaches to a railing above deck, and keeps the cylinders out in the air.If you use charcoal for cooking, be sure it's COMPLETELY cool before disposing of the coals. While the briquettes can be only warm on the outside, the centers can still be glowing hot, sometimes for up to eighteen hours after cooking. I have personally witnessed fires started like this. And, don't use flammable liquids, such as gasoline, for igniting the briquettes. Use starter fluid, starter cubes or similar to ignite your fire.

Be sure to have a fire extinguisher in the galley area, so it is ready for use if needed. Don't mount it over the stove, where you won't be able to reach it if there is a fire.

A fire on board can be a terrifying ordeal for all. Cook safely, and you won't have all those extra guests, from the fire department, on your boat at chow time. They really won't mind not being invited.

Safe Boating!