Diesel tank fill below deck?

[roland stockham]

If spills onto hot surfaces it evaporate producing highly dangerous fumes. Many years ago I was almost killed in a truck when the driver lost consciousness due to a fractured fuel pipe spaying diesel onto the exhaust, the fumes then got sucked into the cab by the heater.

The other factor to consider is the possibility of having to refuel at sea in an emergency, do you really want the possibility of having to lift the hatch in rough seas because you ran short of fuel?

[groundtackle]

I believe common sense needs to be applied. You cannot vent a fuel tank within a confined space.
Chris

[fish53]

Originally Posted by roland stockham

If spills onto hot surfaces it evaporate producing highly dangerous fumes. Many years ago I was almost killed in a truck when the driver lost consciousness due to a fractured fuel pipe spaying diesel onto the exhaust, the fumes then got sucked into the cab by the heater.

The other factor to consider is the possibility of having to refuel at sea in an emergency, do you really want the possibility of having to lift the hatch in rough seas because you ran short of fuel?

While I agree with you about the numerous dangers presented by fuels the hatch issue you present is stretching it a bit. While I agree that in a sea where you cannot avoid large amounts of water continuously washing across the deck having certain hatches doors or windows open would be a problem but a little forethought in design could mitigate this issue easily.

[boatpoker]

Originally Posted by groundtackle

I believe common sense needs to be applied. You cannot vent a fuel tank within a confined space.
Chris

Common sense ..... apparently very rare in this regard.

[hpeer]

So it would seem.

My fills are under the cabin sold, 2” pipe. I stick the nozzle in and I can clearly see where the fill line is. Easier than pumping fuel into a Jerry can.

If I had to refuel at sea in a blow my system would be perfect. It’s on centerline, near center of rotation, most stable place on the boat. I would be down in a protected place, no fear from falling overboard, I can brace myself and support the can while filling.

If I did spill the tank lid makes its own coffee dam.

No hot anything’s anywhere near it.

Vents are higher than tank, vent overboard.

I can’t see anything to not love: in my installation.

[SeaBreeze-1]

You didn't mention the type of sailing you tend to be involved with but, if you're doing a fair amount of coastal cruising or any offshore work, you will likely be carrying some jerry cans with extra fuel. With only 10" of clearance above an internal filler, that's not enough space to dump in a container of fuel. You'd have to incorporate some sort of syphon/temp hose to do that and then... you're back to an external filler.

[groundtackle]

Originally Posted by hpeer

So it would seem.

My fills are under the cabin sold, 2” pipe. I stick the nozzle in and I can clearly see where the fill line is. Easier than pumping fuel into a Jerry can.

If I had to refuel at sea in a blow my system would be perfect. It’s on centerline, near center of rotation, most stable place on the boat. I would be down in a protected place, no fear from falling overboard, I can brace myself and support the can while filling.

If I did spill the tank lid makes its own coffee dam.

No hot anything’s anywhere near it.

Vents are higher than tank, vent overboard.

I can’t see anything to not love: in my installation.

Hpeer, Not able to insure the boat is something not to love, its not legal.
Having full tank access thru clean outs and stand pipes with caps are a good thing. I personally moved 150 gal inside a boat mid pacific after a racor filter body cracked and sucked air. The transfer pump quit, the battery drill pump quit and used the oil change gear to ultimately move all of it to a good working tank. The whole fuel system was poorly engineered and was first on the replacement list once ashore. Mrs Groundtackle was not impressed but on deck would have been far worse.
Perhaps boatpoker could confirm with ABYC. My interpretation is;
Separate fuel line, separate vent, deck fills not in confined spaces or lockers. Deck fills grounded to tank if metallic.
You require the deck fill but having both setups is very good idea.
Chris

[boatpoker]

Originally Posted by groundtackle

Perhaps boatpoker could confirm with ABYC. My interpretation is;
Separate fuel line, separate vent, deck fills not in confined spaces or lockers. Deck fills grounded to tank if metallic.
You require the deck fill but having both setups is very good idea.
Chris

The punch line from ABYC H32 "Ventilation of Boats Using Diesel Fuel" is that The fuel fill must be at least 15" from any opening to the inside of the veesel.

With the fill fitting actually within the interior it defeats the purpose of this standard aimed at keeping carcinogenic (and 40 other toxic vapour compounds) outside.

[Cheechako]

Originally Posted by NPCampbell

Diesel vapors are more explosive than gasoline vapors but are harder to ignite due to a higher flash point.

Diesel fumes are explosive around 0.5% air mixture, while gasoline requires around 1.5%. The flash point is the temperature at which vapors will ignite in the presence of an ignition source, open flame, etc. Gasoline has a flash point that is well below room temperature while diesel is much higher typically around 125-200F. However, some formulations, like 1-D, and additives can lower the flash point to as low as 95F.

If anything warms diesel vapors above its flash point, i.e. a hot engine room, above ground storage tanks, etc, then it can be every bit as dangerous as gas.

That may be technically true, I dont know. But fill a coffee can half full of diesel and throw lighted matches into it. It wont ignite. Try it.

ABYC: As long as you have an ABYC (voluntary by the way) located deck fill you comply. If you happen to use the tank top cleanout to fill... so what, your boat design still complies. I have never had an insurance policy that referred to ABYC by the way. Maybe they do now, I dont know as I'm boatless.!

[Terra Nova]

Originally Posted by boatpoker

The punch line from ABYC H32 "Ventilation of Boats Using Diesel Fuel" is that The fuel fill must be at least 15" from any opening to the inside of the veesel.

With the fill fitting actually within the interior it defeats the purpose of this standard aimed at keeping carcinogenic (and 40 other toxic vapour compounds) outside.

I'm afraid this wisdom falls on the deaf ears of many here who know better than ABYC.

[boatpoker]

Originally Posted by Cheechako

I have never had an insurance policy that referred to ABYC by the way. Maybe they do now, I dont know as I'm boatless.!

Every SAMS Surveyor uses and quotes ABYC and always have.
The photo below is a clip from my survey reports showing what standards I apply.

Most if not all marine insurance companies in North America rely on ABYC Standards.
ABYC Standards are routinely accepted as "best marine practice" in US & Canadian courts.
Not sure how voluntary that makes them in real life vs. technically.

[skipperpete]

Originally Posted by Olddan1943

So if a large commercial ship comes into port, they send someone else out to check the color of the fuel in their tanks? I sort of doubt that.

Tank management and fuel sampling are rigorously conducted aboard ships during the whole bunkering process. Sampling and testing is carried out, samples stored and all is signed for. Ships can be identified for pollution by the sample history. The scrutiny has intensified with the looming introduction of the IMO low sulphur implementation.
Many ships have overflow tanks to contain accidental spills during refuelling.

[MrMatt]

Hello bad.wabbit, I crewed last year on a 51 footer for nine weeks and we only used a fuel fill in the bilges it worked well, slow but no spillage outside the boat and with a small siphon hose overfilling was not a problem, filling and moving the Jerry cans was a pain but that just part of cruising, granted we only were fulling 40 gallons at a time but with a open hatch and even without the hatch wide open the fume level never got strong ever. It sure made sense to me, no rainwater getting in, no deck fill o rings to worry about, and any potential spills contained and cleaned up unnoticed and unreported

[dancor01]

Diesel tank in the engine room? Not a good idea.


The injection pump use diesel to cool itself and lubricate.
That is why there is a return line, so 2/3 of the fuel pumped, get back in the tank.

I have seen bad installations where the tank was under a bunk. Few hours later the mattress was hot to the touch.

[bad.wabbit]

Thanks �� to everyone for their replies. The information, experiences, and opinions were very helpful. There seem to be many installations that are not ABYC complient but may make sense for other reasons. Access, ventilation, or heat from a he engine are not an issue for our tank. Of greater concern would be spilling diesel - which would go into the bilge for a somewhat difficult cleanup. Using the deck fill, a spill would go out the scuppers into the water directly - also not ideal, but proper per ABYC. Pick your poison.

Thanks again to everyone.