[Public-List] Alberg 30 Sail Plan

Gordon Laco mainstay at csolve.net
Thu Mar 11 06:58:54 PST 2021


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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