Originally Posted by roetter
Tying fuel cans to the deck will change the stability of the boat. It may roll a lot more and make the ride more uncomfortable. You will have following seas and follwoing winds most of the way, which like to roll the boat from side to side.
We ran our engines for about 24 hours during the ARC2012 and could have done with much less. At the end some of the crew had no patience and wanted to keep the boat speed above 7 knots at ALL times.
As a backup I would consider a Honda
. You plug
it into the shore power
and charge with your shore charger
. I hope you have a beefy one.
You would rely on your alternator
only. Friends of mine loast their generator
and two alternators during the same crossing. They went black-ship for 10 days. They relied on a handheld GPS
for once a day location update.
I think the Honda
genset is a really good idea for a boat without a diesel genset. The 1000i or 100i would be even better, as you don't need to produce a large current
. And a few jugs of petrol. This will give you completely independent and completely redundant charging
ability, and it will probably consume considerably less fuel per unit of power produced than running your main engine
just to charge batts -- that is, at a time when you don't need propulsion
. This needs to be matched with either a mains charger
which allows you to control the input current
(Mastervolt or Victron), OR a mains charger which is sized to draw about 750 watts (and not much more or much less) at full output. This is important, because the little Hondas are not tolerant of being overloaded, are not happy being run right at full rated power, and on the other hand, running them under 30% or 40% load is not efficient.
Then calculate how many hours of charging
a day you will need and how much fuel will be consumed, and carry that much fuel, and you are totally covered for electrical
power. The 1000i only use about 0.6 liters/hour at full rated power, so 3 hours a day x 21 days would only require 40 liters of fuel -- two jugs. Assuming your power consumption
can be covered with about 2kWH per day of charging as a rough guess (that's about half of what we use on our much bigger boat). It would probably be overkill to take even that much fuel since you have solar
; I guess one jug of fuel would do it.
A reliable diesel genset would be generally better, but you just can't beat the Honda gennie for an extremely cheap
, effective, simple, reliable, no-hassle, no-installation solution to the problem.
Be careful with carbon monoxide -- read up on the dangers. And carry a comprehensive spares kit for the Honda.
Also, if your alternator
is an automotive type -- as delivered with your main engine, as opposed to a heavy duty school
bus type alternator -- keep in mind that it is not designed for bulk power production, and my self-destruct with heavy usage. So I would carry a complete spare alternator plus spares kit including brushes
, and a comprehensive electrical
tool kit. Or else change over to or add as a second alternator a real heavy duty unit.
As to carrying spare diesel -- as a rule
of thumb, on a passage
like this (trade winds) where you would not expect to be doing much motoring, I would think four days, more or less, of non-stop motoring endurance, at your best economy speed (so very slow), should be plenty. How much does your normal tank hold? I don't think most boats will need a whole lot of supplemental fuel for the ARC
if you're not powering a diesel generator. For me, that's 4 liters/hour x 96 hours or about 400 liters; my tank holds 682, so I actually have about 6 days of endurance, not counting genset consumption
(about 6 liters a day). I bet you can ghost along at 2 liters an hour in that boat in a dead calm, so 200 liters might be enough.
I imagine your main tank holds at least that much, so I would think that a few jugs of spare diesel, which unlike jugs of petrol you can simply carry in the lazarette, will be fine, as an emergency
reserve. No need to clutter up the deck or mess with bladders. You are a sail
boat, after all.