Diesel tank fill below deck?

[bad.wabbit]

Question to the group - what are the potential pros and cons of moving the diesel tank fill below deck into the engine room? Our tank fill is currently in the cockpit, on the bridge deck. The fuel hose then runs vertically into the main cabin, does a 90 degree turn through a bulkhead, then another elbow to end up into the tank (forward top corner of the tank). The tank also has a fill port (capped at present) that is in the aft top corner. This one is easily accessible from the engine room. It is about 10" below the engine room hatch. There is oogles of clearance to bring a fill hose down and fill the tank directly, or use at temporary extension to raise it out of the hatch such as a Baja Filter. There is plenty of space such that jerry cans could also be used to fill the tank directly if refueling at sea.

Pros: Cleans up the bridge deck by removing the fitting, less chance of spilling diesel on a seating area or into the cockpit, no chance of water ingress into tank.

Cons: potential diesel spill into bilge while filling.

Thoughts?

[fish53]

What are your tanks made of? It may be possible to add a small cofferdam around the fill tube to contain a gallon or so spill. I had engine room fills on my commercial fishing boat which had fiberglass built in tanks. I had a piece of fiberglass pipe ten inches in diameter and simply glassed a six inch section around the fill. You'll want well sealing caps on the fill and make sure your vent is clear. It may also be possible to cut off a appropriate sized funnel to hose clamp around the filler neck to contain a small spill. I never liked having flush fills outside, water always gets in the fuel.

[denverd0n]

One problem is that there is always a release of fumes when you are filling a tank. You don't notice it much with an outside fill, but I'm pretty sure you would be nearly overcome by it with an inside fill.


Beyond that, diesel fumes are not explosive the way that gasoline fumes are, but the folks selling you diesel may have policies and rules that don't take that difference into account. Hence, they may refuse to take their hose down into your boat, because that would be a nearly suicidal thing to do when dispensing gasoline.


I guess what I'm saying is that I would check with a few places first, to see how they would feel taking their hose down into your boat for a fill-up.

[bad.wabbit]

Originally Posted by denverd0n

One problem is that there is always a release of fumes when you are filling a tank. You don't notice it much with an outside fill, but I'm pretty sure you would be nearly overcome by it with an inside fill.


Beyond that, diesel fumes are not explosive the way that gasoline fumes are, but the folks selling you diesel may have policies and rules that don't take that difference into account. Hence, they may refuse to take their hose down into your boat, because that would be a nearly suicidal thing to do when dispensing gasoline.


I guess what I'm saying is that I would check with a few places first, to see how they would feel taking their hose down into your boat for a fill-up.

Good insight. I have a nominally 30"x30" hatch opening so access and ventilation should be ok. But you are correct that the fuel dock operator may have an opinion.

[Cheechako]

On one boat, which had venting issues and would sputter out fuel from the vent and you had to fill real slow. .....If I needed a lot of fuel, I just opened the floorboard and the inspection hatch on the tank. It was a quick opening hatch. Easy to fill, you could fill like you're filling a mega yacht! Full flow, no venting issues etc.

[fish53]

It's relatively hard to be overcome by diesel fumes in the open and it would be foolish to take fuel below deck in an enclosed space. What I believed we were talking about was having a hatch with the fills below and the concern was keeping any spillage from going into the bilge. As with any fueling operation the utmost care should be taken.

[hpeer]

On our 33’er, Steel, converted the keel voids into fuel tanks. I welded in covers with vents and fills and an inspection plate. I get some strange looks when I take the hose below but it’s OK. Went through survey with no comment except to paint the fill caps yellow.

It may have some diesel smell, don’t know, I’m pretty immune to it by now. Doesn’t bother the Wife or I. So I’m good.

[NSboatman]

It’s probably not allowed by abyc or EU rules (on a new build anyway)... but it’s not uncommon, and frankly in my opinion it’s very practical. I’ve had a couple boats like this, and it sure allows you to fuel quickly and cleanly when you have a 4” hole to pour the fuel in through. Just make sure you have excellent ventilation, and that 4” (or whatever) port is 100% fuel tight when closed. The little plastic inspection ports used in cockpit seats and the like are NOT suitable. Must have a positive and fuel-resilient seal.

[boatpoker]

Originally Posted by NSboatman

It’s probably not allowed by abyc or EU rules (on a new build anyway)... but it’s not uncommon, and frankly in my opinion it’s very practical. I’ve had a couple boats like this, and it sure allows you to fuel quickly and cleanly when you have a 4” hole to pour the fuel in through. Just make sure you have excellent ventilation, and that 4” (or whatever) port is 100% fuel tight when closed. The little plastic inspection ports used in cockpit seats and the like are NOT suitable. Must have a positive and fuel-resilient seal.

Surprised your surveyor didn't mention Transport Canada Small Vessel Construction Standards.

[fish53]

Originally Posted by hpeer

On our 33’er, Steel, converted the keel voids into fuel tanks. I welded in covers with vents and fills and an inspection plate. I get some strange looks when I take the hose below but it’s OK. Went through survey with no comment except to paint the fill caps yellow.

It may have some diesel smell, don’t know, I’m pretty immune to it by now. Doesn’t bother the Wife or I. So I’m good.

Funny, I didn't know you could be immune to cancer and kidney disease?

[basssears]

FWIW I have been to two fuel docks that would not allow anyone on the boat while the boat is being filled. Everyone had to be on the dock while I filled leaning off the dock, I had to swing around so my fuel fill was on dock side (couldn't even stand on deck while filling).


Struck me as weird and maybe just a random thing, but that would be a challenge with a below deck fill unless your arms are REALLY long

[fish53]

Originally Posted by basssears

FWIW I have been to two fuel docks that would not allow anyone on the boat while the boat is being filled. Everyone had to be on the dock while I filled leaning off the dock, I had to swing around so my fuel fill was on dock side (couldn't even stand on deck while filling).


Struck me as weird and maybe just a random thing, but that would be a challenge with a below deck fill unless your arms are REALLY long

That is weird, fueling large vessels at many docks you need someone at each vent, the fill and in the engine room monitoring the tanks and of course someone on the dock all with communication like a handheld vhf.

[pcmm]

Originally Posted by basssears

FWIW I have been to two fuel docks that would not allow anyone on the boat while the boat is being filled. Everyone had to be on the dock while I filled leaning off the dock, I had to swing around so my fuel fill was on dock side (couldn't even stand on deck while filling).


Struck me as weird and maybe just a random thing, but that would be a challenge with a below deck fill unless your arms are REALLY long

That's a gasoline thing usually. It's quite common for all crew/passengers to be required to be of the boat when filling a gasoline fueled boat.

[boatpoker]

No one on board and only the fuel dock attendant allowed to fuel (diesel or gas) the boat is the law in Ontario and some states.

[hpeer]

Been to a lot of marinas where the attendant is NOT allowed to fuel, Owner must, and is therefore responsible for spill fines.