Vertical petrol fuel tank?

[Franziska]

Hi,

I had a bit of an unconventional thought today.

At first the current situation.

We do have 2 Yamaha 9.9 outboards, as well as a petrol genset onboard.
So we will continue using petrol as our fossile fuel until there are better alternatives.
Our current 60l (about 16Gal) petrol tank is located in the bridgedeck under the setee in a dedicated compartment where it can vent off to the underwing outside.

The mast is deckstepped on the bridgedeck roof and it's base located about 1.3m (roughly 4ft) from the fuel tank.
We have two metal forestays and apart from this Dyneema rigging.
Both engines have pump ball hoses attached and get fuel from that tank. They are located below the tank.

Secondly we cook with Propane so far. I am not a big fan of either as both, petrol fumes, as well as Propane are heavier than air.
While I'd like to get rid of the Propane and use alcohol instead (let's not start a discussion on which fuel is better please), my boyfriend and onboard chef prefers the Propane for convenience.
Even though I do know the advantage of Propane and know that there are 1000's of safe installations around I just don't like it.
Still I do think about how to make the whole setup reasonable safe.

Now here is the question.

If we were to keep the Propane system after all I am thinking of putting the petrol tank in the same location (it's in the aft focusle of one hull which is gastight separated from the rest of the boat and has a vent through a hose above the waterline.).

So to say jokingly, our "bomb" locker, all high risk stuff in one location.
Another plus is that the petrol tank and Propane bottle are than almost 5m (approx.12ft) from the mast base away which seems much better in case of a lightning strike.

The problem is, we can not fit the current horizontal tank there.

Is anyone seeing a problem with using a vertical petrol tank instead?

An advantage of the vertical tank would be its reduced free surface effect inside and that both risky fuel are only in one dedicated compartment with nothing else inside.

My main concern is that I am not sure if the flow from the pump ball fuel hoses is creating enough lift for the engines to get enough fuel, as well as I am a bit concerned if the engine fuel pumps can handle this.

The bottom of the tank would be perhaps 0.75m (approx 2 ft) below the engine heads when the outboards are in their "down" position and operating.

I'd like to avoid any extra petrol pump.

So far I could not source a suitable vertical petrol fuel tank over here in Europe.
Anyone knows where I could get that?

If we fit the fuel tank in that location, I make sure it can drain fumes similar as the petrol bottle.

Any thoughts or ideas on this?

[Franziska]

I might ask, also, would one of these drums work if I'd install some suitable fittings into the lid?

https://www.amazon.co.uk/Litre-Plast...bb_marketplace

Does anyone know if the can withstand petrol? It's HDPE as is our current petrol tank.

Remember, everything is located in a gas proof separated compartment aft.

For the ventilation I could even put this drum into a bigger drum and than have the petrol fumes vent through a hose at the bottom of it overboard above the DWL.

[Jammer]

Around here people routinely place the gasoline (=petrol) tanks in the lowest part of the bilge in small fishing boats, so that the bottom of the tank is several inches (about 10cm) above the outboard motor's cavitation plate. Works fine as long as the fuel pump in the outboard is in good shape and there are no air leaks.


I believe that co-locating the propane and gasoline tanks amplifies the risk rather than reducing it but that is just my opinion.


The blue plastic drums are made of polyethylene which is permeable to gasoline. You have to use something actually designed for use with gasoline to get a safe, environmentally sound installation. The commercial marine gasoline tanks, at least in the USA, use a multilayer construction with a vapor barrier, which is why they are expensive.


Your existing setup seems better designed and I cannot imagine why you would change it as you propose. I think your suggestion that lighting would pose a greater risk with the fuel tank 4' from the mast is farfetched. Gasoline is not explosive or unstable and will not be affected by a nearby lightning strike unless the tank wall is compromised (melted/burned) by the strike.

[Cheechako]

One thing: Alcohol is crazy slow to cook with. If you cook much you won't like it.
Tank:
-A fuel tank under the cabin settee seems pretty weird. But the weight is central, so hmm not bad.
-Many cats have a fuel tank behind the cockpit in/below the cockpit settee structure. good gravity feed etc. Any room there? (I dont know what your boat looks like)
-I'm not sure it's considered kosher to have propane and gas in the same enclosure. You are likely creating a worse situation.

[Franziska]

Hey thanks for your thoughts.

Regarding amplifying the risk, I rather have one higher risk dedicated compartment with a big sign on it than several high risk areas spread over the boat.

We are talking about a petrol tank, not about gasoline.
Gasoline (=Diesel) is less at risk from the lightning, I still think the petrol (=Benzine) tank close to the mast foot is a bit dangerous.

Good info with those fishing boat tanks!

Originally Posted by Jammer

Around here people routinely place the gasoline (=petrol) tanks in the lowest part of the bilge in small fishing boats, so that the bottom of the tank is several inches (about 10cm) above the outboard motor's cavitation plate. Works fine as long as the fuel pump in the outboard is in good shape and there are no air leaks.


I believe that co-locating the propane and gasoline tanks amplifies the risk rather than reducing it but that is just my opinion.


The blue plastic drums are made of polyethylene which is permeable to gasoline. You have to use something actually designed for use with gasoline to get a safe, environmentally sound installation. The commercial marine gasoline tanks, at least in the USA, use a multilayer construction with a vapor barrier, which is why they are expensive.


Your existing setup seems better designed and I cannot imagine why you would change it as you propose. I think your suggestion that lighting would pose a greater risk with the fuel tank 4' from the mast is farfetched. Gasoline is not explosive or unstable and will not be affected by a nearby lightning strike unless the tank wall is compromised (melted/burned) by the strike.

[rslifkin]

If you're worried about propane and have a generator, what about going to an electric stove and using the generator to cook for less fuel types?

[Cheechako]

Originally Posted by Franziska

Hey thanks for your thoughts.

Regarding amplifying the risk, I rather have one higher risk dedicated compartment with a big sign on it than several high risk areas spread over the boat.

We are talking about a petrol tank, not about gasoline.
Gasoline (=Diesel) is less at risk from the lightning, I still think the petrol (=Benzine) tank close to the mast foot is a bit dangerous.

Good info with those fishing boat tanks!

Yeah, Gasoline in the US is your "Petrol" I guess....

[Franziska]

It's worth giving it a thought, even though I prefer running our genset less and not more :-)
If you are baking stuff it will take a lot of power if you run it for an hour or so.

But than we are baking only about twice a week. I'll calculate it.

Originally Posted by rslifkin

If you're worried about propane and have a generator, what about going to an electric stove and using the generator to cook for less fuel types?

[Franziska]

Uups, this is confusing between the languages.
Sorry about that.

We are talking BENZINE here.

Originally Posted by Cheechako

Yeah, Gasoline in the US is your "Petrol" I guess....

[Chotu]

You are describing my EXACT solution to the same problems..

First, it’s genius to locate all your hazards in a single compartment. (Pats self on the back... ha ha)

There is absolutely no issue putting all the flammable things in a single space. In fact, there are a lot of advantages. I have an explosives locker too. All connections are located inside it and it has big holes in the bottom, through the bridge deck, to allow vapors to drain below the bridge deck. The fuel filter, all propane Y fittings, gasoline/petrol tank selectors, all located in the same box for ultimate safety.

Next the outboards.

Yes, you may find some difficulty moving fuel from lower than the Outboards. My outboards are lower than or almost at the same height as the tanks, but they will not run forever after a hand priming with the squeeze bulb. Eventually they stop getting fuel. I think this is because the fuel goes up very hight through a watertight bulkhead, almost to hull deck level, then back down to the outboards in the wells. This requires a fuel pump and is not ideal. I’d prefer a gravity system, but it’s 150 gallons (560 liters) of fuel so having it low is necessary for stability. I use a 12v automotive fuel pump to keep fuel flowing to the outboards and have a spare after seeing they don’t last too long.

My tanks are also tall and narrow like you are describing. I have 3 of them. They are rectangular and make a fuel area with 3 different 50 gallon tanks with limited free surface area, given they are tall. So no baffles required. They are standard Moller below decks fuel tanks.

[Franziska]

Thanks for that great to hear that it works for you.
Wow 560l fuel that's a lot, you must have a big boat and/or engine.

Good to know about the 12v fuelpump if it does end up posing a problem.
I have given this a bit more thought now, and I may get away with it. On most outboard driven boats the external tank is a foot or two below the head of the engine.
So, it may be OK.

Regarding the tanks, thanks for the company name. I'll look that up.

Further I did learn that these drums exist also in a "pure liquid" version without the big cover, but standart screw in fittings.

https://www.amazon.co.uk/Plastic-Tig...bb_marketplace

Originally Posted by Chotu

You are describing my EXACT solution to the same problems..

First, it’s genius to locate all your hazards in a single compartment. (Pats self on the back... ha ha)

There is absolutely no issue putting all the flammable things in a single space. In fact, there are a lot of advantages. I have an explosives locker too. All connections are located inside it and it has big holes to allow valors to drain below the bridge deck. The fuel filter, all propane Y fittings, gasoline/petrol tank selectors, it all in the same box for ultimate safety.

Next the outboards.

Yes, you may find some difficulty moving fuel from lower than the Outboards. My outboards are lower than or almost at the same height as the tanks, but they will not run forever after a hand priming with the squeeze bulb. Eventually they stop getting fuel. I think this is because the fuel goes up very hight through a watertight bulkhead, almost to hull deck level, then back down to the outboards in the wells. This requires a fuel pump and is not ideal. I’d prefer a gravity system, but it’s 150 gallons (560 liters) of fuel so having it low is necessary for stability. I use a 12v automotive fuel pump to keep fuel flowing to the outboards and have a spare after seeing they don’t last too long.

My tanks are also tall and narrow like you are describing. I have 3 of them. They are rectangular and make a fuel area with 3 different 50 gallon tanks with limited free surface area, given they are tall. So no baffles required. They are standard Moller below decks fuel tanks.

[Chotu]

No problem. I looked at the same round barrels you are looking at, but concluded you can store more fuel in the same area with a square or rectangle tank.

This is the one I got. I have 3 of these forming a square fuel cell area.

It is also better because a fuel gauge and all the proper pickups are already built in.

It has a vent, a fuel fill, a fuel pickup and a fuel gauge sender already installed.

My boat is 50’ catamaran with two 30hp outboards. But, I do not like to go to get fuel. So I want to be able to motor a long distance or run a generator for a long time between fuel dock visits.

[Franziska]

Your are absolutely right that the square one holds more fuel.
The reason that drum jumps a me is its price and that I do not want to overload the back of the boat anyway.
The 60l are good for us, same size as our current tank.
We have much smaller engines, and a few spare fuel canisters too, which I keep for the dinghy.

Do you happen to have thoughts on our current setup of the Benzine tank so close to the mast foot (lighting issue)?

[Chotu]

Originally Posted by Franziska

Your are absolutely right that the square one holds more fuel.
The reason that drum jumps a me is its price and that I do not want to overload the back of the boat anyway.
The 60l are good for us, same size as our current tank.
We have much smaller engines, and a few spare fuel canisters too, which I keep for the dinghy.

Do you happen to have thoughts on our current setup of the Benzine tank so close to the mast foot (lighting issue)?

I think lightning is completely unpredictable and your fate is in the hands of chance with lightning.

However, the only thing that can cause problems (I think) for a benzine/petrol/gasoline tank is if it melts from some metal getting too hot next to it when the lightning strikes. So make sure no metal is touching it or very close to it. So maybe make some distance between the propane tank and benzine tank.

[Cadence]

Ever consider an electric pump for a day tank. You can buy fuel tanks gas and diesel in any no. of stock shapes.