[Public-List] Alberg 30 Sail Plan

Tue Mar 16 11:18:33 PDT 2021

Diesel electric is a good technology for ships when it serves the
arrangements well.  If you are forced into compromises such as a very long
shaft, or increasing section beam aft to accommodate an engine, then it can
pay off.  It works well for vessels that use as much electricity for house
or for weapons as for propulsion. In these cases physically separating the
energy conversion from the propulsion motor can work well.  In an A30 , you
simply add weight and complexity to go diesel-electric, unless you
significantly reduce the requirements for speed and range.   The gains in
propulsive efficiency will be small - we already have a good match with
small diesel and gas engines - so for matching peformance, your diesel
generator will have to generate 16 or so horsepower, and you will need a 16
hp motor.  You could use a smaller engine combined with batteries , and run
it longer , but that will get heavy quickly.

For those willing to limit their A30 to daysailing or short cruises, and
who have power at the pier to recharge, all-electric might work, replacing
the fuel storage.  Let's say I want a minimum 3 hours of 6 knot steaming in
my batteries. That's 3 hours at 12 kw, 36 kw-hours. at 12 volts that's 3000
amp-hours, or quantity  30 12V, 100 amp-hour batteries. A 16 hp (12 kw)
electric motor is smaller and lighter than a 16 hp diesel, gaining you say
4 or 5 100 amp-hour batteries - maybe more if you can be weight-efficient.
You could replace that energy nightly , but would need a fairly
sophisticated charging system to deliver 36kw - hour in say 12 hours, so
3000 watts. At 120 V that's 25 amps, just below a 30 amp dock connection.

At a mooring the required solar panels are going to be very heavy and large.
   A quick look at solar panels finds 320 watts peak in a 1.7m  x 1 m
panel. Lets say I can fit 3 of those somehow, getting 1.6 kw peak.
Assuming about 5 peak hours ( residential panel sizing uses numbers like
this) we get 8 kw-hours/ day so need 2 days to fill the batteries back up,
allowing me to daysail every 3rd day.

Of course others can have a different use case, but I consider a diesel or
gas engine integral with the A30 design. If I had a customer who wanted a
diesel-electric  or an all-electric 30 foot sailboat, I could help design
it, but it would not be an A30.

Mike
Rinn Duin #272

On Thu, Mar 11, 2021 at 11:54 Gordon Laco via Public-List <
public-list at lists.alberg30.org> wrote:

> I reckon the limiting factor to making electric practical for cars or
> boats is battery performance. Technology has a way to go yet.
>
> I was reading the other day about the ‘green’ aspect of engines… the
> writer was making the case that electric, particularly electric using
> lithium batteries, pushes pollution out of our sight but loads it on the
> third world.
>
> The writer made the case that so far the ‘greenest’ engine is a well tuned
> diesel.  Non-complex metals in its construction (mostly just iron), no
> reliance on solar or shore based electrical generation which has it’s own
> particular polluting issues more complicated than the soot and CO from the
> diesel’s exhaust…
>
> Sounds like heresy I know…
>
> Many large commercial vessels use well proven diesel-electric propulsion.
> A smaller diesel than would be required if it drove the prop directly runs
> at optimum speed for fuel economy and emission reduction, spinning a gen
> set that in turn powers electric propulsion.  I have wondered sometimes
> that yachts don’t use that system…
>
> Gordon Laco
> 426 Surprise
>
>
>
>
> > On Mar 11, 2021, at 11:43 AM, Mike Lehman via Public-List <
> public-list at lists.alberg30.org> wrote:
> >
> > I know of one Alberg 30 with an electric motor. To get any range it
> needs 2
> > sets of batteries...600 lbs each...yields about 2-3 hours of motoring
> >
> > Mike Lehman
> > ~~~_/)_/)~~_/)~~~
> >
> >
> >
> >
> > On Thu, Mar 11, 2021, 9:59 AM Gordon Laco via Public-List <
> > public-list at lists.alberg30.org> wrote:
> >
> >> Hello Dave, good morning, welcome aboard.
> >>
> >> There’s so much below that needs unpacking I’m not sure where to
> begin.  I
> >> don’t mean that unkindly, so please don’t take it that way..
> >>
> >> So jumping to the ballast references… it is utterly and completely
> >> impossible to remove the ballast without embarking on a large and
> technical
> >> and very expensive engineering project.  I suppose it would be possible
> to
> >> remove the deck, remove the interior, chisel out the glass work holding
> the
> >> encapsulated ballast in place, drill lifting bolt holes into the iron,
> >> thread lifting rings into the holes, then arrange a gantry or crane to
> >> perform the lift…. while having found a way to hold the shell of the
> hull
> >> down while upwards force was applied to the ballast pig… huge force
> much in
> >> excess of the weight of the iron to break it loose from the skin of the
> >> keel.
> >>
> >> Alternative to all that, one might saw off the ballast area of the keel
> >> from the outside, then build a new keel…
> >>
> >> Regardless, in order to come even remotely close to the density of the
> >> iron the yachts were built with by stacking batteries as ballast, would
> >> require a much larger volume of space than is currently occupied by the
> >> iron.  Ball parking the amount of space in a battery that is NOT
> lead…I’d
> >> venture that you might need four or five times the volume.   But… that
> >> volume is extra displacement (floating ‘energy’), so just to sink it
> you’d
> >> need even more batteries… where would you put them?  And so the
> impossible
> >> circle would go…
> >>
> >> So, the short answer is… it is not practical to remove the ballast,
> >> particularly with the intention to replace the ballast with batteries.
> >>
> >>
> >> Gordon Laco
> >> www.gordonlaco.com
> >>
> >>
> >>
> >>
> >>> On Mar 10, 2021, at 9:24 PM, Dave Yamakuchi via Public-List <
> >> public-list at lists.alberg30.org> wrote:
> >>>
> >>>
> >>> Hi everyone, I'm Dave, skipper of Aquila, Hull #47 (1964/65.) Work &
> >> sail in Chicago, mooring can at the mouth of Burnham Harbor.
> >>>
> >>> I had a few questions, but first, some background: 'Aquila' doesn't
> have
> >> an Atomic 4, she has a Graymarine.  It needs a bunch of stuff.  And it's
> >> 400+lbs, _without_ the exhaust pipe. The cockpit sits, I suspect, a bit
> >> closer to the water than it should be maybe, if you catch my drift.
> Giant
> >> saddlebag lazerette gas tanks probably don't help.
> >>>
> >>> So, I'm tearing that gak out.  I'm going electric.  With lots of lead
> >> batteries.
> >>>
> >>> Anyway, the mast isn't moving. But I'm definitely 'moving' significant
> >> weight forward from the aft. Will she still sail right? I'm considering
> >> allocating a few hundred pounds of batteries or so to the motor's former
> >> location just to try and not wreck the fore/aft balance too badly,
> though
> >> I'm going in resigned to the fact that it's going to happen anyway.
> >> amidoinitrite?  I'm the electrical guy, not the sailor.  Certainly never
> >> been a shipwright.  You all tell me. Please. The original batteries were
> >> under the cabin floor, so right now Plan A is shoehorning as many more
> >> pounds of 12V lead as is practical in there, plus whatever extras in the
> >> engine compartment.
> >>>
> >>> I'm wondering though: has anyone here ever accessed or removed their
> A30
> >> keel ballast?  What shape / size is it?  Is it tapered? Will it come out
> >> the companionway with a crane maybe?  Is this crazy talk?  IDK. I'm
> >> basically getting a crane to help pull the motor anyway.  3300lbs of
> lead
> >> batteries is rather a lot of power too. It would be a stretch, but I
> could
> >> probably swing it.
> >>>
> >>> She's my first boat. I figured I'd ask some experts during the planning
> >> phase...
> >>> Here's what I know:
> >>>
> >>> * The 70lb 12V type 31s claim about 80 AmpHours or '195 minutes at 25A'
> >> which equals maybe 1/3hp for 3hours or so, conservatively.
> >>>
> >>> * Three of those gets 1hp, six of them does 2hp, etc. For that same
> >> duration. Use less hp than that, get longer runtime, obviously.
> >>>
> >>> * Replacing the displacement of a 419lb motor and transmission gets
> >> about six times 70lbs.
> >>>
> >>> * Plus two batteries 'existing' is eight.
> >>>
> >>> * The ballast is 3300lbs.
> >>>
> >>> * 47 x 70 lb batteries is 3,290lbs.  48 batteries x 25A per battery x
> >> 12V is 14.4kW.  19hp.
> >>> * This leads to propeller questions, however, perhaps you get the idea.
> >>> * I want to replace the iron ballast with lead.
> >>>
> >>> Why won't this work?
> >>>
> >>> How could it?
> >>>
> >>> What's the best place for those batteries?
> >>>
> >>> Can I get the batteries into the keel like I want?
> >>>
> >>> Opinions please.
> >>>
> >>> Thanks in advance and best regards.
> >>> Dave
> >>> _______________________________________________
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> >>>
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