[PUP] Fuel consumption Was: The right boat

[Scott Bulger]

Arild again made a number of great points, to which I comment:

A:  Several smaller tanks may be a better bet despite the increased cost of
additional piping and valves.
S:  It's not the cost of piping and valves, but the complexity of manifolds
and in/out combinations that must be balanced against the value.  I was on a
N46 with 5 tanks and the skipper spent a lot of time considering where fuel
was coming from and going to.  I concern myself with only Port or Starboard,
list one way, draw from the heavy side till trim.

A:  Vessel trim with full and empty tanks is also something that needs
consideration. We have seen plenty of posts from Krogen owners discussing
the heeling characteristics as tanks are burned empty and the fuel is
shifted side to side.

S:  Krogen owners aren't alone in this respect.  Everyone I know spends time
managing fuel load.  You can tell how much fuel is on a N40 by how bow down
it is!  When below 20% of full my bootstripe at the bow submerges.  Fill it
up and out it comes!  Boat also handles better with lots of fuel, seem more
stable.

A:  What happens if you have a bad load of fuel and need to filter and pump
all
the fuel over to the other tank.
S:  If both tanks are full, where are you going to pump it?  This is a real
issue!

A:  As a minimum a third tank with at least 48 hours fuel burn capacity is
required. This now becomes the CLEAN FUEL reservoir and  is never
compromised by filling directly from shore. It only gets filled from the
fuel polishing system.
S:  Does this mean your two days away from the source of bad fuel?  Maybe
I'm crazy, but I see myself finding out asap and going back to the source
and offloading the fuel back to them, then asking them to make it right.  I
guess this is naove but I'd like to find our asap that the fuel I got was
bad.

Second issue.

A:  However the reality is you may buy a trans-oceanic vessel but will not
get
around to making such a passage for a long time.
S:  This is what I did, bought the boat a year ago and departing now.  A
year is NOT a long time to learn a boat, as a matter of fact it seems a very
short time at this moment  :)

A:  A number of posts have been made regarding empty tanks and condensation.
S:  I subscribe to David Pascoes' believe that condensation in fuel tanks is
an urban legend:
http://www.yachtsurvey.com/myth_of_condensation_in_fuel_tanks.htm


A:  Now that I am working full time in a naval architect design office, I
find
myself spending a great deal of time considering all these issues. <Grin>
Then I get to put concept to paper and eventually see it built. <VBG>
Working full time with four other naval architects has proven to be quite
the education.
S:  I for one can't wait to see the products that come from your efforts.  I
have no doubt the will be some of the finest engineered solutions brought to
market anywhere!  We are fortunate to have you as a contributor to this
forum!  Scott

Scott Bulger, Alanui, N40II, Seattle WA