I'm having some weight distribution issues with my new boat.
Now, since we are talking hobbyhorsing or pitching, (bow up, stern down, etc...), the discussion is exactly the same as for a monohull
, with the exception that I don't have that extra bit of weight at the fulcrum point of the pitching.
Here are the problems:
1) I have Yanmar
YM30's in the engine
rooms, with 6 Trojan batts even farther aft than those Yanmars and a whole lot of fuel tank
back there as well. The boat sits stern-heavy before loaded with anything.
2) There is no weight at all in the bows. The shoot skyward pretty easily, and that's where the berths are. I was in a rough anchorage last night on purpose to see how the boat did. It pitched me up and down a lot while trying to sleep.
3) I have a little tad of moisture in the hull
near the exhaust overboard
discharges because they submerge when I'm underway at a good clip under power.
So, I have too much weight astern. But here is what I'm thinking.
There are, theoretically, two extremes to configure weight on the boat:
1) All weight in the middle of the hulls, including engines, water tanks
, etc... This would make nearly 100% of the weight at the center (looking fore and aft). This would make it so the bows and sterns would adjust very quickly to the waves, having almost no moment of inertia around the fulcrum of the "see saw." I think this would make my comfort situaiton worse, but would make for increased seaworthiness, since you would have a hard time pitch-poling or stuffing a bow or burying the deck
I have that runs to the ends of the bows.
2) All weight could be equally divided and stuffed in the bows and sterns. This would make it so the boat had its greatest moment of inertia around the balance point of the see saw. This would be like having two really fat kids
on each end of the see saw. It would pitch/hobbyhorse *very* slowly compared to the first scenario. However, would this make me more apt to dig the bows in and run into trouble when it comes to seaworthiness?
This is where I'm stuck.
Which of the above is better?
I'd like the comfort of a huge moment of inertia, but fear the seaworthiness might go down.
Monos have an added moment of inertia to counteract pitching without any penalty in seaworthiness (as described in this thought experiment). They have the keel
. It is *below* the boat, so its mass keeps the boat from pitching without putting weight in the ends (just like the weight of the mast
does on both types of boats).
So... given my engines and gear
in the aft are pretty heavy, how can I shuffle my personal stuff and tools so that I will have a comfortable ride and remain seaworthy
Do I put weight in the bows to even the boat out, making up for the extra weight in the stern I have from the large engines, fuel
and batteries? This would decrease the ptiching motion at anchor
, and at sea but is that seaworthy
Or... do I try to center all my weight in the hull
, but move it just a little bit forward of center to coutneract the extra engine
weight that is pulling my stern down too much? This would keep a high degree of pitching motion, but allow my bows to pop up quickly if stuffed.