Fuel Tanks, Batteries etc in same compartment

Discussion in 'Boat Design' started by Mat-C, Dec 5, 2012.

  1. Frosty

    Frosty Previous Member

    Your too good at it. Mythbuster just could not get a tank to explode by shooting it.

    Sure a leaky tank could explode if you ignite it with jumper cables but thats not what the OP asked.

    Your are assuming this guy has a teribble maintained boat, how do you know that.

    Facts please just facts. Do you want me to explain the OP question.

    He wants to know if there are regulations about having a fuel tank in the same compartment as a battery etc. Nothing more.

    He is not going to blow up and die a horrible death. His tank is not leaking or his battery loose,---nor is he jumping or smoking causing sparks.

    The answer is simply as I stated and that was ---probably,-- though why is unclear.
  2. watchkeeper

    watchkeeper Previous Member

    Come on Tunnels, with all the BS we put up with in China, I see no reason for having to accept BS theories on a forum for thinking people
  3. FMS
    Joined: Jul 2011
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    Location: united states

    FMS Senior Member

    Based on the fact that fuel tanks have been found leaking, a leak could happen at some time. Therefore the best design should take this possibility into account and have a "plan B" built in - forced ventilation of the compartment containing the tank where vapor would collect if or when the tank fails.
  4. Frosty

    Frosty Previous Member

    I could not agree more ---why are you here.
  5. Frosty

    Frosty Previous Member

    I think you should stay at home ---far too dangerous to got out.
  6. FMS
    Joined: Jul 2011
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    Location: united states

    FMS Senior Member

    Boating is safe enough when proper precautions are taken based on the information available.
  7. watchkeeper

    watchkeeper Previous Member

    Getting childish Frosty
  8. watchkeeper

    watchkeeper Previous Member

    Getting silly Frosty
  9. Frosty

    Frosty Previous Member

    Exactly ---thats what we want precaution on information available.
  10. Mat-C
    Joined: May 2007
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    Location: Australia

    Mat-C Senior Member

    Much as it pains me to say so.... Frosty is right:eek:
    I was simply asking what the regulations are regarding having tanks and electrical components sharing a space.
    I fully understand the risks involved: Indeed that is the situation at the moment! The tank is located in the same compartment as the engine and batteries.
    I was simply considering moving them fwd for reason's already stated. It's not the only option - just one I was thinking of....
  11. jonr
    Joined: Sep 2008
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    Location: Great Lakes

    jonr Senior Member

    Another option to move weight is batteries. I have a theory that with an ultra-capacitor booster (yes, they make these) near the engine, longer cable runs wouldn't be an issue.
  12. BertKu
    Joined: May 2009
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    Location: South Africa Little Brak River

    BertKu Senior Member

    Fully agree, Maxwell makes 2600 Farad , 2,5 Volt for 20 USA$ , What it means, you need at least 6 in serial, to be higher than 14.4 Volt with a small reserve. Although 7 is better. 2600 with 7 in serial becomes 371 Farad at 12 Volt, with spikes of max 17.5 Volt (Although I assume that the manufacturer also has a small reserve in their 2,5 Volt). The law of Ohm is .785 x 371 x 0.01 Ohm = 2,7 Seconds. 0.01 Ohm = more than 1000 Ampere starting current. Good enough to start your engine in winter and summer. As long the Caps are mounted as close as possible to your starter motor
    P.S. The 2.7 second is the absolute minimum time, In view that the battery will feed the Super capacitor while starting your engine, the time to have enough energy in the capacitor is very much longer. The advantage is , in winter your engine will start quicker than on a battery alone.
    Last edited: Dec 13, 2012
  13. troy2000
    Joined: Nov 2009
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    Location: California

    troy2000 Senior Member

    Mythbusters is a TV show. It isn't real life. Please tell me you don't go to television actors when you're looking for boat expertise....

    The lower explosive level for gasoline is 1.4% of atmosphere; the upper limit is 7.6%. Obviously, your average gas tank still in use will likely have fumes it in with a higher mix of gasoline to air than that; any explosion would occur outside the tank if it's breached, after the fumes have been diluted and then ignited.

    Old gas tanks with just some gasoline leavings in them, like the two that went blooey on me, are a lot more likely to have fumes in them that are between the lel and uel.
    You're assuming the boat is perfectly maintained and always will be, and there will never be the slightest fuel leak or spillage.

    I think it's safer to assume that if something can go wrong, sooner or later it will. You live your life based on your assumptions, and I'll stick to mine.
  14. Frosty

    Frosty Previous Member

    Sleep deprivation again, Mr Grumpy. Mythbusters is a TV show yes --A TV show trying to bust American myths like do petrol tanks blow up when gangsters shoot at them.

    To ignite fuel you need a spark .

    A spark that is hot enough to ignite --a cigarette but wont do it.

    Are your bullets made of lead by any chance.

    You said,-- Sooner or later it will go wrong? well yes that right --is that what he asked for, future maintenance procedure.

    So where will the spark come from ?

    Lets keep to some facts eh"?

  15. watchkeeper

    watchkeeper Previous Member

    I had a friend arrive at my workshop with a 100lt International Acko fuel tank wanting a small welded modification.

    He said the tank had been emptied, flushed, washed out (hot water) & inert gas purged then blown with compressed air.

    I put my mig welder nozzle to the tank start welding, as soon as the wire feed touched the tank the bloody thing internally exploded splitting wide open fortunately opposite side from me.

    Since then I never attempt repairs on fuel tanks just replace them. Nowadays my tanks are usually 2000 to 5000lt each at 60000lt plus total capacity and hold fuel oil.
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