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From: Mark Richter (no email)
Date: Tue May 13 2008 - 17:40:21 EDT
Peggy,
First, consider whether something heavy can be moved farther aft or
lightened. Maybe that old, rusty 300 ft of 1/2" chain could be replaced
with 150' of 5/16" HT? Perhaps the battery banks can be moved 5 feet aft in
the engine room?
The friends at a party idea is a good one for determining how much ballast
is needed. Be sure to have them stand near the area you have selected for
the ballast. Where to put the needed ballast depends largely on what's
already in your bilge areas. Though I've been aboard, I can't really
remember what's aft and down low. The best place to put ballast for your
bow-down trim condition will be low, near the centerline, and aft, but not
all the way to the transom. Say around 6-12 feet forward of the transom
would be best, if that area is available (under the aft-cabin sole,
perhaps?). Putting ballast too near the bow or stern can contribute to
excessive pitching in a seaway.
One of the easiest types of ballast is to simply mix some bags of ready-mix
concrete, and pour it in the desired area. It forms itself to the existing
hull lines, and will readily form a nearly level top surface with a little
help from a screed. You will want to slope this surface slightly in one
direction or the other to ensure drainage of any water that lands on top.
Lead pigs are good, and allow one to change their position at some time in
the future, but are rather costly, and can be difficult to secure (unless
there is a handy structure like engine bearers or a bulkhead to which they
can be thru-bolted).
Before pouring concrete, consider the drainage of the bilge toward the
pumps, and install PVC or other forms to allow bilge water to pass the
ballast on its way to the lowest part of the bilge. Install an extra pipe
of about 1" diameter higher up, for the routing of any future wires and
cables that might be desired later. Good luck on your project, and let us
know how it comes along.
Mark Richter, M.E.
m/v Winnie the Pooh
Heading up Chesapeake Bay tomorrow
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