Here in the US, you cannot place the fuel tank in the same compartment as
the motor(s). If it is plastic, it has to have at least passive ventilation
with scoops facing fore and aft. Regardless, if it has a fuel sender or
other electrical wiring in the same compartment, it has to be force
ventilated and there are rules for the sizing of the vents and on flow
rates. Since it sounds like you are using gasoline, it might be worth your
while to have a professional look at it since regulations vary
country-by-country.

Something else to keep in mind is that the original designer put the fuel
way up in the bow and may have taken this into account when he did his final
design (longitudinal center of gravity). How's the boat float and run when
it is empty and the bow tank is low on fuel? Any tendency to porpoise? If
it's sits reasonably level at rest and is stable and satisfactory in this
condition when using the boat, then you should be fine putting the fuel
amidships as you are. As a rule of thumb, try to keep the fuel's CG at
around 1-1/4 waterline beams forward of the transom. If your new fuel tank
location moves the CG too far aft, then the most likely affect will be a
tendency to porpoise ...and the porpoising may come and go depending on
speed, will likely be more likely in smooth water and may disappear in a
slight chop (since it lengthens the effective wetted length of the hull).
If your boat sits too low in the stern (a swamping hazard when in rougher
seas with people standing in the stern ...easier for waves to come in), or
it shows a tendency to porpoise (especially if it gets violent), then you'll
want to move your fuel back forward -or- always carry weight in the bow
(ballast) to compensate.

Have fun,
Brian



"Hans-Joachim Sellner" wrote in message
...
Hallo!
I would like to get some advice concerning gasoline-tank-installation in a
motor boat:
After completing the repowering of my boat with a dual-caburated motor I
looked for a reliable position for the fule tank, previously installed in
the bow by the manufacturer. Because there was enough volume near the
center of buoyancy, I decided to place the tank there, tightly screwed and
taped on the extensions of the motor-stringers. Although this position
might be physically the best one, fuel-lines could be held quite short and
servicing is easy, I've some strange feeling: The tank is in direct
neighbourhood in line to the engine, there are at least 5 inches between
them, no separating wall or plate made of epoxied plywood or alu, steel,
... is installed. Now my question:
Are there any rules or regulations (coast guard) prohibiting the
installation of a fuel-tank in nearly the same compartment with the
engine?
By the way: Of course the tank is connected to motor-ground as well as the
copper-lines and the water-separator are grounded to the tank. A correctly
dimensioned blower to suck gasoline-fumes is installed.

What do you think, anything left I've to work on? Any advice will be
appreciated!

Bye, Hajo

Brian D wrote:

Here in the US, you cannot place the fuel tank in the same compartment as
the motor(s).

REALLY! Thats a bit drastic isn't it?
Must make fitting a day tank a real pain, especially if you like having the
day tank above the level of the injector pumps (allows the use of gravity
feed to the engines). Or does this only apply to your main tanks, in which
case I really don't see the point, as a decent day tank will contain enough
fuel for quite a respectable fire!

Since it sounds like you are using gasoline, it might be worth
your while to have a professional look at it since regulations vary
country-by-country.

Ohh, is this petrol specific, that makes more sense now, I was thinking
diesel or heavy oil rather then petrol (Which IMHO is just wrong for
anything except outboards).

Regards, Dan (who is very glad he lives where the coastguard don't try to
pull this crap).

Brian, where do you find that requirement? I've searched quite a few sites
for reference to regulations including http://www.nyss.com/federal.html#3M
and not found such a statement.

There are requirements for ventilation and statements that one shan't have
fuel in the bilges, requirements for fire extinguishers, etc. but nowhere do
I find the requirement for a bulkhead between the fuel tanks and the engine.

Would it maybe one of the voluntary standards, or maybe specific to one
state?

Roger

http://home.earthlink.net/~derbyrm

Brian D wrote:

Here in the US, you cannot place the fuel tank in the same compartment as
the motor(s).

I think everything you need to know about fuel tank and fuel system
installation is in Title 33 of the CFR:
http://www.access.gpo.gov/nara/cfr/w...cfr183_99.html

You may also want to spend some time plowing through Title 46...which
won't be easy. And then there are the CG regs...their site is almost
impossible to find anything on!

--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://www.seaworthy.com/store/custo...0&cat=6&page=1

Peggie Hall wrote:
I think everything you need to know about fuel tank and fuel system
installation is in Title 33 of the CFR:
http://www.access.gpo.gov/nara/cfr/w...cfr183_99.html

You may also want to spend some time plowing through Title 46...which
won't be easy. And then there are the CG regs...their site is almost
impossible to find anything on!


Interesting, Peggy...

Quoting from Title 33:

" Subpart J--Fuel Systems

Sec. 183.550 Fuel tanks: Installation.

(a) Each fuel tank must not be integral with any boat structure or
mounted on an engine."

Would this mean that a monel fuel tank glassed into a sailboat keel would be
illegal ?

Brian C

Brian Cleverly wrote:
Interesting, Peggy...

Quoting from Title 33:

" Subpart J--Fuel Systems

Sec. 183.550 Fuel tanks: Installation.

(a) Each fuel tank must not be integral with any boat structure or
mounted on an engine."

Would this mean that a monel fuel tank glassed into a sailboat keel
would be illegal ?

D'd if I know...I only remembered tripping over some fuel tank regs
while searching for waste plumbing regs, and since I was having a slow
afternoon, went looking for 'em again.

However, If do seem to remember something in my search that said
glassing of foaming in any fuel tank is a no-no...but I could be wrong,
and I'm not gonna hunt it down again.



--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://www.seaworthy.com/store/custo...0&cat=6&page=1
http://shop.sailboatowners.com/detai...=400&group=327

Well sorta. The ABYC regs state that a gas tank cannot JUST be supported by
plastic foam. It's OK to foam a tank in, but you have to provide additional
supports. Probably because the long term strength of the foam, for support,
probably degrades.

Brian



"Peggie Hall" wrote in message
.. .
Brian Cleverly wrote:
Interesting, Peggy...

Quoting from Title 33:

" Subpart J--Fuel Systems

Sec. 183.550 Fuel tanks: Installation.

(a) Each fuel tank must not be integral with any boat structure or
mounted on an engine."

Would this mean that a monel fuel tank glassed into a sailboat keel would
be illegal ?

D'd if I know...I only remembered tripping over some fuel tank regs while
searching for waste plumbing regs, and since I was having a slow
afternoon, went looking for 'em again.

However, If do seem to remember something in my search that said glassing
of foaming in any fuel tank is a no-no...but I could be wrong, and I'm not
gonna hunt it down again.



--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://www.seaworthy.com/store/custo...0&cat=6&page=1
http://shop.sailboatowners.com/detai...=400&group=327

I think this is what I was remembering ...the bit about not mounting ON an
engine. I did a search of my ABYC and USCG regs and can't find a statement
that specifically states that the fuel tank cannot be in the same
compartment as the engine. I sit humbly corrected. My apologies.

Brian



"Brian Cleverly" wrote in message
...
Peggie Hall wrote:
I think everything you need to know about fuel tank and fuel system
installation is in Title 33 of the CFR:
http://www.access.gpo.gov/nara/cfr/w...cfr183_99.html

You may also want to spend some time plowing through Title 46...which
won't be easy. And then there are the CG regs...their site is almost
impossible to find anything on!


Interesting, Peggy...

Quoting from Title 33:

" Subpart J--Fuel Systems

Sec. 183.550 Fuel tanks: Installation.

(a) Each fuel tank must not be integral with any boat structure or
mounted on an engine."

Would this mean that a monel fuel tank glassed into a sailboat keel would
be illegal ?

Brian C

Yes ... a bit drastic. I did some research in my copies of the ABYC and
USCG regs to check my memory and you're right ...nothing says you cannot
have the tank in the same compartment as the engine. That said, note that
you are disallowed from mounting a tank ON an engine. I think that's what I
was remembering. You do have to meet the ventilation requirements that I
stated though.

Brian


"Dan Mills" wrote in message
...
Brian D wrote:

Here in the US, you cannot place the fuel tank in the same compartment as
the motor(s).

REALLY! Thats a bit drastic isn't it?
Must make fitting a day tank a real pain, especially if you like having
the
day tank above the level of the injector pumps (allows the use of gravity
feed to the engines). Or does this only apply to your main tanks, in which
case I really don't see the point, as a decent day tank will contain
enough
fuel for quite a respectable fire!

Since it sounds like you are using gasoline, it might be worth
your while to have a professional look at it since regulations vary
country-by-country.

Ohh, is this petrol specific, that makes more sense now, I was thinking
diesel or heavy oil rather then petrol (Which IMHO is just wrong for
anything except outboards).

Regards, Dan (who is very glad he lives where the coastguard don't try to
pull this crap).

Dan Mills wrote:
Brian D wrote:


Here in the US, you cannot place the fuel tank in the same compartment as
the motor(s).


REALLY! Thats a bit drastic isn't it?
Must make fitting a day tank a real pain, especially if you like having the
day tank above the level of the injector pumps (allows the use of gravity
feed to the engines). Or does this only apply to your main tanks, in which
case I really don't see the point, as a decent day tank will contain enough
fuel for quite a respectable fire!


Since it sounds like you are using gasoline, it might be worth
your while to have a professional look at it since regulations vary
country-by-country.


Ohh, is this petrol specific, that makes more sense now, I was thinking
diesel or heavy oil rather then petrol (Which IMHO is just wrong for
anything except outboards).

Since I am about to install the tank in my boat as well I have read
through the rules that the CE marking in Europe are based on.
A gasoline tank can not be installed in the same compartment as the
engine, there must be a gas/air tight wall between them. For a diesel
tank there are no such rules.

--
Oddgeir
I'm building a boat: http://www.oddgeirkvien.com/baat