100 Gallon Fuel tank under V-Berth?

[Cosmos]

I'm currently looking at a boat that has a custom 100 gallon aluminum fuel tank that the owner recently installed under the V-berth. Do you think the weight of a full tank would be of any concern in how the boat handles under sail? Or would it be negligible...

Does anyone have any experience with a tank in this location?

It's a 36ft boat, displacement 16,500 lbs.

Thanks!

[Eleuthera 2014]

Serious weight off the center line... why did the PO do this?

[JPA Cate]

Originally Posted by Cosmos

I'm currently looking at a boat that has a custom 100 gallon aluminum fuel tank that the owner recently installed under the V-berth. Do you think the weight of a full tank would be of any concern in how the boat handles under sail? Or would it be negligible...

Does anyone have any experience with a tank in this location?

It's a 36ft boat, displacement 16,500 lbs.

Thanks!

Cosmos,

You don't need the forum to figure this out. A pint's a pound, the world around.

So, 2 pints = 1 qt and 4 qts. to a US gallon. so, 8 pints = 8 lbs/gallon, therefore 800 lbs.

Okay, if average weight of a 6'3" man is 200 lbs, then what you're talking is about 4 of those guys standing on the foredeck.

I'm only a girl type, but that seems like a lot of weight forward, what do you think?

Ann

[kentobin]

My anchor and 300 feet of chain come in at around 600 lbs and makes the bow to heavy pulling it down. This is a 37 foot cutter 26,500 lb. displacement. It does effect steerage but I couldn't tell you how much as I bought the boat used and have never sailed her without the extra bow weight. Allegedly this weight causes weather helm.
Helm Balance – Center of Effort, Lateral Resistance, Centerboard, Mast Rake - Waves « Jordan Yacht Brokerage

One gallon of light crude runs 6.84 lbs and the amount of fuel in your 100 gallon tank won't always be 100 gallons so your trim will always be changing. Also how tall is the tank?

How much space does this tank take? Just wondering how much storage you'll lose and if you'll have room for a chain locker or much else.

If you're really interested in the boat just make sure you get an experienced surveyor. A good one can save you from making a questionable purchase or save you lot of money. Most owners think their boat is worth way more than it really is.

[GordMay]

Greetings and welcome aboard the CF, Cosmos.

[boatman61]

The best way to find out is take her for a sail and see what YOU think.. are YOU happy with the performance/balance..
Personally I would not like a fuel tank under my main sleeping accomodation.. however I've owned boats that had water tanks under the V-berth and they sailed just fine.
Its all about how YOU balance the boat when you laod it.. sounds like he (the PO) was a Motorboater rather than a sailor..

[denverd0n]

First, I agree with boatman61. Second, I would ask what was designed to be under there? A lot of boats put a lot of weight under the v-berth. Water tanks, or anchor chain, or at the very least just storage space. So, it's not like the designer expected NO weight to be up there.

Diesel fuel weighs about 7.3 lbs/U.S. gallon. So 730 lbs. for 100 gallons, if you keep the tank full. Of course, if there used to be a water tank up there, water weighs about 8.3 lbs/U.S. gallon. If there used to be a holding tank up there, then waste weighs even more than water (though I've never seen a 36' boat with a 100 gallon holding tank!).

[rwidman]

Remember that a tank of any kind will vary in weight based on how full it is. This tank (if you choose to use it) will weigh as much as 800 lb and as little as 0 lb . That change in weight will certainly affect the way the boat handles.

Tanks are best placed near the center of the boat where the variation in weight has less effect on the handling.

[a64pilot]

Still, maybe 100 gls there is better than 50 on deck in Jerry cans?

IF I ever make the Pacific crossing, I wouldn't mind extra fuel, just because the tanks there does not mean you have to fill it

Depends I think on if you have a need for a bunch of extra fuel, most I think don't

[bsurvey]

check the CFR's the fuel tank location is not legal


never mind what it will do to the boats performance

[bsurvey]

33CFR 183,550 (h)

[roverhi]

If you plan on using the v berth, will you be happy with fuel sloshing around under you. The tank better have very good baffles to muffle the fuel movement.

[a64pilot]

The CFR's are regulatory for the boat manufacturer, but are they for the owner?
Aircraft are the only vehicle that I am familiar with that have to be maintained IAW the CFR's?

[cal40john]

Originally Posted by bsurvey

check the CFR's the fuel tank location is not legal


never mind what it will do to the boats performance

Originally Posted by bsurvey

33CFR 183,550 (h)

OP did not specify what fuel. If the fuel is diesel, subpart J, which is all the .500 section, 183.5XX, does not apply at all. I haven't found any rules applying to diesel installs on rec. boats.

§ 183.501 Applicability.
(a) This subpart applies to all boats that have gasoline engines, except outboard engines, for electrical generation, mechanical power, or propulsion.


If you are talking about gasoline, then according to the way I read the trail of sub sections, the tank could very well be legal. How do we know the tank is not appropriately labeled by the manufacturer, and not tested at 25 g's for forward mounting instead of 15 g's for aft mounting? Be one expensive custom tank though.


Weight forward depends on the boat. In general I agree with others, likely not a good idea. Cal 34's do not sit on the lines molded in by the manufacturer. Close to 100 gallons of water in the vberth made the boat sit on its lines. It reduced pounding upwind significantly, and the boat felt like it sailed better, didn't get actual speed numbers to see if it was faster. Only drawback was the bow was wetter.

[cal40john]

Originally Posted by a64pilot

The CFR's are regulatory for the boat manufacturer, but are they for the owner?
Aircraft are the only vehicle that I am familiar with that have to be maintained IAW the CFR's?

I knew that the CFRs for nav lights specifically state that they are regulations for manufacturers (in rec boats section), but didn't notice until you brought it up that subpart J starting at 550 is for manufacturers.

eCFR — Code of Federal Regulations

Manufacturer Requirements

§183.550 Fuel tanks: Installation.


But there are still plenty of rules in the 183.5XX before that pertaining to gasoline fuel tanks and their installation, so presumably apply to everyone.