[Public-List] Alberg 30 Sail Plan

Gordon Laco mainstay at csolve.net
Thu Mar 11 08:54:17 PST 2021


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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