[Public-List] Adding weight to the keel and other things

Mon May 2 13:45:22 PDT 2011

One of the other boats in our Sea Scout program is a Pearson Triton 25. 
When we got her, she had a couple or three dead batteries up forward as 
far as they could be stowed.  Initially we were wondering why. That was 
before we took the rudder off and found out! -  It has a lead rudder, or 
at least a heavy rudder weighing in the vicinity of 300-350 lbs - it 
took three people to lift it back into place.  Those batteries were used 
to offset the weight of the rudder - but it didn't take 1000 lbs - more 
like 90-100.  For some reason all the heavy storage items batteries, 
fuel and water are all toward the aft of the boat.

One of our Kittiwakes is set up with about 1250 lbs of encased lead 
ingots and 250 lbs of movable lead ingots.  I find the closer to the 
center line and balance point of the boat that I keep the movable 
ingots, the better handling and more stable the boat is.  Moving even 50 
lbs of them from the bilge area to a quarter berth storage area effects 
the handling.  Far better to keep the lead where it is meant to be - low 
and in the middle of the boat and and use the crew for what it is best 
used for - movable ballast.  You can move the crew around a lot faster 
than the lead.

For what its worth,

Bart Knapp
Hull 388 (not 368 as previously posted)

On 5/2/2011 3:13 PM, Gordon Laco wrote:
> Half a ton up forward in a 25 footer... That's a lot....
>
> I would suggest that while she may motor faster in a dead calm; as a sailing
> boat I would be certain that she is suffering from all that weight forward.
> How is it fixed? If it isn't, it could be quite dangerous.
>
> I'd recommend getting it out.  You'll find you have a new, nimble and joyous
> boat!
>
> Gord #426 SURPRISE
>
>
>
>
> On 02/05/11 4:08 PM, "dan walker"<dsailormon at yahoo.com>  wrote:
>
>> so all u nautical architects a question. i have a cape dory 25 that the
>> previous
>> owner deemd it a good idea to add 1000 pounds of lead under the v bitrh.
>> cosnequently she sits soewhat bow downsuch that the side decks do not drain
>> aft
>> as designed. he sailed her on the gulf of mexico. i ssume he thought it made
>> her
>> more stable? any thoughts? why? leave it alone?
>>
>>
>>
>> ----- Original Message ----
>> From: Gordon Laco<mainstay at csolve.net>
>> To: Alberg 30 Public List -- open to all<public-list at lists.alberg30.org>
>> Sent: Mon, May 2, 2011 11:16:45 AM
>> Subject: Re: [Public-List] Adding weight to the keel and other things
>>
>> Hi Roger -
>>
>> The trouble with 'balancing' by moving ballast forward is that the yacht's
>> pitching moment goes up dramatically.... What would be gained through better
>> trim is lost (and more) due to the increase tendency to 'hobby-horse' or
>> pitch.
>>
>> Fascinating stuff.... One thing's connected to the next thing....
>>
>> Gord  #426 SURPRISE
>>
>>
>> On 02/05/11 10:53 AM, "Roger L. Kingsland"<r.kingsland at ksba.com>  wrote:
>>
>>> Len,
>>>
>>> I just drilled a hole through the centerline just aft of the seat between
>>> the forward V berth for my transducer.  I discovered, on good old 148, the
>>> forward edge of the keel is about 6" aft of the seat bulkhead and just a few
>>> inches under the V berth sole.  Between keel and hull is what looks like
>>> grey sand (perhaps a mixture of sand and cement) that is easily chipped
>>> away.  I understand from other Albergers that the cast iron keel is
>>> encapsulated in this stuff so you will have to go thru it when fastening new
>>> lead.  Since the weight of the keel is partially held in place by the bottom
>>> of the fiberglass, I would be concerned about removing any glass.
>>>
>>> Given Gord's comment about squatting and the keel running so far forward, I
>>> wonder if it might be necessary to add weight forward of the bottom of the
>>> keel to achieve "balance" (a navel architect should be able to figure that
>>> out).  I have also noticed that the leading (diagonal) edge of the hull, up
>>> to about 3 feet forward of the bottom, is flat and have thought rounding
>>> that section would reduce drag.
>>>
>>> If the weight needs to be forward of the flat part of the keel, you could
>>> add a curved "tongue" that would attach to both the flat and diagonal parts
>>> of the keel fastening it vertically through the fiberglass to the existing
>>> cast iron.  Of course you would have to insure a good connection of the new
>>> keel bolts to the bottom of the cast iron and it would add a few inches of
>>> draft.
>>>
>>> The other issue is how you get access to the bottom of the keel.  I kept my
>>> boat in a factory with 20 ton overhead cranes for a few years and thought
>>> about lowering the boat on its side with the keel and curve of the hull on
>>> the factory floor.  I actually bought a 4' x 8' "dunnage bag" to place under
>>> the curve of the hull.  Dunnage bags are inflatable and placed between cargo
>>> to stabilize it.  Turns out their load capacity is quite high.  I thought,
>>> by putting good old 148 on her side it would be easier to finish the hull.
>>> Unfortunately, I got evicted before I could try it.  The bag is yours if you
>>> want it.
>>>
>>>
>>>
>>>
>>>
>>>
>>> Roger Kingsland, Managing Partner
>>>
>>> Kingsland Scott Bauer Associates
>>>
>>>
>>>
>>>     KSBA
>>>
>>> ________________________________
>>>
>>> Architects/Planners/InteriorDesigners/ProjectManagers
>>>
>>>
>>>
>>> 3441 Butler Street
>>>
>>> Pittsburgh, PA 15201
>>>
>>> N 40° 27.8344'  W79° 57.9831'
>>>
>>>
>>>
>>> 412-252-1500 ext.101
>>>
>>> 412-779-5101 cell
>>>
>>> 412-252-1510 fax
>>>
>>> r.kingsland at ksba.com
>>>
>>> www.ksba.com
>>>
>>>
>>>
>>>
>>>
>>> -----Original Message-----
>>> From: public-list-bounces at lists.alberg30.org
>>> [mailto:public-list-bounces at lists.alberg30.org] On Behalf Of Len Payne
>>> Sent: Monday, May 02, 2011 9:51 AM
>>> To: public-list at lists.alberg30.org
>>> Subject: [Public-List] Adding weight to the keel and other things
>>>
>>> Good Morning, All,
>>> I have been considering how to add weight to an under-weight keel.
>>> One of the things I have been thinking about is stripping the glass from the
>>> keel in an area just above (3 or 4 inches) the bottom of the keel and nearly
>>> the full length of the keel in that area. Then, by drilling and tapping 2
>>> 1/2" holes into the keel, through lead plates, to hold the plates to the
>>> keel on both sides. The plates would be 24" x 6" x 1", three on each side -
>>> laid lengthwise - end to end, would total about 1/2 cuft of lead (about
>>> 350#, 1 cuft = 708#). Each plate would weigh just under 60#, so would be a
>>> manageable weight. The plates would be faired according to it's position on
>>> the keel and would be bolted to the side of the keel, epoxied in place, and
>>> glassed in to become an integral part of the keel. This would add nothing to
>>> the draft and would only a 2" to the width of the keel. The additional
>>> 300-350# would be no more than that of a large passenger, or a big skipper
>>> and beer, so it should not affect the way the boat rides in relation to the
>>> waterline. Furt
>>>   her, being 3-1/2' below the waterline, spread out along the keel length,
>>> fairly 'centered' relative to the center of gravity, the trim should not be
>>> significantly affected - certainly no more than a 40gal water tank under the
>>> V-berth (330# plus, above the waterline, very far forward). The additional
>>> "Righting Moment" of 300-350#, 3-1/2 feet below the waterline would,
>>> certainly, not be negligible.
>>> If one were about to strip the hull because of the need for a barrier-coat,
>>> how much additional work would it be to remove the glass down to bare iron
>>> (if the keel is cast) or attaching the plates to the outer skin of the keel
>>> and through-bolting to the opposite plate, then glassing the whole thing in
>>> place.
>>> Yes, I really want you comments, else I would not be soliciting same. Are
>>> there things that I have not considered? Other possible effects from doing
>>> this? Does anyone know "exactly" how the keels are constructed? Are they
>>> junk iron cast in epoxy, are they glassed, cast iron? Has anyone seen a keel
>>> that has come apart?
>>> Yes, I welcome any and all comments and/or suggestions.
>>> Thanks to all in advance.
>>> Len
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>>
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