Blowers ON or OFF during refueling

BON DIA

BON DIA

Member
Oct 5, 2006
356
Boerne TX / Lake Travis AUS TX
Boat Info
'05 340DA, C80 w/ 2KW Radar
Engines
6.2s w/Vdrive
Question raised during discussion by experienced boaters of a boat exploding in SE TX in '06 after refueling....should blowers be ON or OFF while refueling?
 
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Bon Dia,

blowers should be off. So should all electronic devices, bilge pump, etc. No lighters, cigarettes, etc. close cabin door. when fueling is complete, hang around the dock for a bit while paying, don't be in a hurry. Open engine hatch, and cabin, smell for fumes, look for gas. If all clear, then it is o.k. to run blower, bilge, etc., prior to starting.

I think i've covered all. others may wish to add.

Gregg
 
Personally all power off while fueling. Blower on after sniff test.
 
I don't see what the big deal is!
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Blowers off until the gas cap is back on. Let the blowers run while you pay, don't let them rush you. I tell them there tip depends on it.

Plus don't overfill, once the gas starts coming out the vent, you'll never be able to tell where the fumes are coming from.
 
Wow. Who would've thought?

[rant]
If the mere act of *running* the blowers during fueling is a hazard: then I say that boats are equipped with the wrong type of blowers, and that the typical blowers used for ventillation are a safety hazard and should NEVER be used.
[/rant]

[mega-rant]
The issue here, I suppose, is that the electrical components of the blower could create a spark that could detonate fuel vapor. Therefore, you don't want to run these things if the atmosphere is flammable. Sounds reasonable, but. . .

The problem I have is that if the atmosphere is flammable -> How do you get the vapors out? Most bilges are on the BOTTOM of the boat. Opening an engine hatch on the top does almost NOTHING to get the vapors out. Do you expect heavier-than-air fumes to rise up and out? Won't happen. The vapor will eventually dissipate through diffusion. . but that would take HOURS. You really need forced ventillation to get the fumes out.

Here is the rub: YOU CAN BUY MOTORS DESIGNED FOR USE IN FLAMMABLE ATMOSPHERES. In my industry, we have all sorts of "intrinsically safe" and "hazardous area rated" electrical equipment. Why wouldn't bilge blowers be rated for "hazardous area"? If you can safely use a standard electrical motor.. . then the area by definition is "non-hazardous", and by definition you don't need forced ventillation. In a "non-hazardous" area, you can use your cell phone in the engine compartment while you are starting it.

The only reason not to have a "hazardous area" rated bilge blower is because such a blower would be expensive. Expensive in the same way air bags add to the price of a car. (would you buy a car without airbags in 2007?).

This issue sounds intuitively crazy.
[/mega-rant]
 
Well. . .diesel is inherently less flammable than gasoline .. . . . .it takes a good deal of "spark" to light that off.
 
I think the point about not running the bilge blower is that you would not want to accidentally draw fumes into the boat while fueling.

Gary, not so much of an issue with diesel as you know, but a good, noisy blower will drown out the sound of the screaming kids.
 
Well... I'll be honest. I don't even run my blowers before I start the engines. The blowers are mounted at the top of the engine room with no plumbing to the bilge floor and wouldn't even remove gas vapor sitting on the floor if it got in there. I think the blowers are there just to cool the engine room down and suck the hot air out... hence I usually leave them running when at idle, trolling, 30-60 minutes after I dock, or at the fuel dock. OK... and here's something I do that is REALLY BAD I guess... I carry a gallon jug of diesel fuel in the bilge AND I usually leave the generator running when I come in to grab fuel... At the place I get fuel there are a lot of sport fish boats (Vikings, etc) and you are lucky if they even turn the engines off...

I'm not recommending you follow my careless behavior. I've also been known to leave my generator running overnight at anchor... of course this is DIESEL and not GAS.
 
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My understanding of doing the sniff/visual test is to make sure that 1) there is not a seriuos amount of fumes to ignite, and 2) that there isn't any fuel in the engine compartment (never know when a gas line may let loose).

Remember, safety is no accident...
 
I don't think any amount of spark can light off diesel. Diesel combusts due to heat/pressure. It is not necessary to use the blowers on a diesel boat, but I do run them the whole time the boat is on, if nothing else just to help circulation in the engine room. At night on the hook I will use the generator all night too, w/o the blower on.
 
Well. . .these bring up some interesting point.

I have to look at my boat more closely to see where the blower is taking suction. I tend to DOUBT there is a duct taking suction from the bottom of the bilge. But that's where it should draw from.

- - - - -

On a diesel boat, Jim hit the nail on the head. An electrical spark won't ignite the vapors. Diesel engines don't have spark plugs, right? Fuel vapors is a non-issue.

- - - - - -

As for generators: They are not intended to run on the hook, right? But the issue here will be proper ventilation of the boat and proper exhaust ducting. This would apply to both the generators AND the engines. Both diesel AND gasoline. This should work right *by design*, but if something goes wrong, that's why CO monitors are CRUCIAL in cabins.

I don't think leaving blowers running while engines are running is a bad idea for any boat.

- - - - - -

As for ventilation while fueling: If I was writing a procedure from scratch, I would call for lifting the engine hatch while fueling. Getting a bilge fulll of fuel is something you want to know about IMMEDIATELY. If you have the hatch closed (like I do) and only get drops, then I would want the blower running so that the stuff is vented BEFORE I build up to a flammable atmosphere.

When I fuel, I am generally standing on the engine hatch (so it is down). And I run the blower the whole time. I suppose I could get away with not running the blower, but then I would only feel comfortable by raising the hatch when done to verify that safe condition exists.
 
Why don't you think generators are meant to be run on the hook? When a boat is on the hook the ass end should be downwind, which is where the exhaust comes out. So the exhaust should never be an issue. Good CO2 detectors are important though. Where people might have an issue is if they are in a big raftup and the boats are not able to swing. Then the exhaust might have an opportunity to make its way in the boat. On smaller boats you can usually pop a hatch to get air through the boat on the hook, so running a gen is not a big deal. But on larger boats it is pretty important to be able to run the gen all night for Air Cond as some parts of the boat are pretty well buried and this is the only way to get air to them.
 
What are the odds that while fueling a gas boat, a fuel fill line breaches inside the engine room? It happens and I wouldnt want to take the risk. Nothing electrical running.Period. Open the hatch and take a peek and a sniff also before starting engines.
 
admin said:
Why don't you think generators are meant to be run on the hook? When a boat is on the hook the ass end should be downwind, which is where the exhaust comes out. So the exhaust should never be an issue. Good CO2 detectors are important though. Where people might have an issue is if they are in a big raftup and the boats are not able to swing. Then the exhaust might have an opportunity to make its way in the boat. On smaller boats you can usually pop a hatch to get air through the boat on the hook, so running a gen is not a big deal. But on larger boats it is pretty important to be able to run the gen all night for Air Cond as some parts of the boat are pretty well buried and this is the only way to get air to them.
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Off topic...
I agree 100%. And, after spending all that money on a generator you better believe I'm going to use it when I need it most. On topic, I always turn my blowers off when I gass up.
 
admin said:
Where people might have an issue is if they are in a big raftup and the boats are not able to swing. Then the exhaust might have an opportunity to make its way in the boat.
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Great point Jim. The only time my CO detectors ever went off I was rafted up next to a boat with a gas generator running. My neighbor had no intention to running the generator all night, but we were all surprised in how quickly the CO accumulated in my boat. Thank God for those alarms!
 
Blowers good
Blowing up bad

Yeah nothing electrical on while fueling. Period.

as to Deisel Gary's Deisel wessel, yeah you needen't be too alarmed although it's a good practice to stay in step with the NO SMOKING at the fuel dock. I always found it funny that you stop and start from the fuel dock with motors running; and while you're fueling up the guy that is pulling in has all his bell and whistles running
 
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