AVOID THE BOAT BOOM WITH
PROPER VENTILATION OF FUMES
Fred Dyson – Dyson's Starboard View – Messing About in Boats
Gasoline vaporizes at normal air temperatures, and because it is heavier than air, it sneaks into the lowest spot in your boat. The gasoline vapor will then wait in your bilges like a ninja assassin.
This treacherous tendency of gasoline has prompted prudent operators to install fuel vapor detectors and bilge blowers to deal with the problem. Always check the bilges and vapor detectors and run the bilge blowers before you start a gasoline inboard engine!
In addition, many marine power plants have the starters and alternators mounted high on the engine to get the possible sparks out of the vapor-laden portions of the engine compartment. All potential sources of leaks, spills, and sparks must be eliminated.
I remember when I was a kid, my dad ran a boat marina and my mom ran the fuel dock. Mom was in our boat galley making dinner and dad was putting gasoline into a thirty-four-foot cabin cruiser.
Some electrical device must have caused a spark in the bilges, because it blew the boat apart.
The man of the boat was blown off the aft deck into the water, but the woman on board got the wildest ride. It seems that she was sitting on the head (toilet) and the explosion in the bilges below her launched her right through the top of the boat. Apparently, the top of the cabin of the boat was fairly flimsy and did not impair the passage of the woman or the thunder jug she was riding.
My dad was utterly astonished to see this woman and her mount rise up before him, and. described a graceful trajectory into the water some forty feet away. Dad got his picture in the paper for fishing the shocked woman out of the water with a boat hook.
Her husband had some second-degree burns, the boat was a complete ruin, and the woman was physically unharmed but reported strange emotional disturbances and inconvenient personal dysfunction . My dad speculated that she probably had trouble using the "facilities" on boats for the rest of her life.
Gasoline leaks on a boat must be inspected and chased relentlessly. Fill hoses and vents need attention and every compartment should he vented. Savior Pappetti told me about a Bristol Bay boat that blew up because it sat at an unusual angle on a barge and fuel vapor had gotten into a compartment in the fo'c'sle. Pappetti has some amazing claims about how far he got blown on that one.
I worked around two different large aluminum skiffs that were turned into bombs by a combination of errors. One had a 454 Chevy inboard and jet; the other had two 125-hp outboards.
Over the years they had been modified for several kinds of workboat service. On both boats, the fuel tanks had been enlarged and new fuel filler fittings had been installed. The problem was that the old and disconnected fuel filter fittings were still on the side of the cabin.
New and inexperienced deck hands cheerfully pumped three hundred gallons of gasoline into the old fittings and thus into the bilges. This, of course, turned the skiffs into floating bombs. Fortunately, the skippers returned and gauged the fuel tanks before they started the engines. With empty tanks, they started looking for the fuel, and finally found it in the bilges.
As I heard it, the language used by the skippers was hot enough to have torched off the fuel. One of the offending deckhands compounded his offense by getting an industrial vacuum cleaner with frayed wiring and a non-explosion-proof motor to use to blow the vapor out of the bilges. He is now known as the "bomb" and is working on a hog farm in Kansas.
A fire at sea can ruin your whole day, and an explosion at the fuel dock is very embarrassing. Cure the leaks! Vent your bilges!
