Trim - I'm 2" Off and It's Driving Me Crazy!

[rebel heart]

Just wondering if anyone has any good ways they deal with trim and balanced weight distribution.

We had our mast off for a while, with the boom on the starboard deck. Seems like that kept us in trim, and now that the rig's back on, I'm a couple degrees (2" of waterline) to port.

[MarkJ]

Sit to starboard and eat icecream till you are level.


With us it depends on which water tank we are using and how much fuel on board etc.

[rebel heart]

That's kind of what worries me; my fuel and water are primary admidships, but even a bit to port (where I'm listing).

I'm kind of anal retentive about trim :-(

[senormechanico]

Get a multihull and you won't notice it as much.

Steve B.

[Bash]

I solved a similar trim problem in my last boat by installing a third 4D battery to the house bank, as far outboard as the bilges would allow. Solved the trim problem while giving me enough extra power to make in through a long weekend without having to charge.

[Fishspearit]

Now you know the other reason why cruising boats have jerry cans all along the deck, it's not just for extra tankage!

[SabreKai]

My boat was just out of a major rebuild when I bought her, and they had just dumped the ballast in where ever they saw fit. She sat with her stern down but ok port/starboard. With 3 people in the cockpit she would drag her tail like a tired old dog.

This summer, I first moved all the old chain I found in the stern lockers to a rubber basin on the fore deck. Then I put a five gallon Jerry can full of water up there. Finally I stopped along the highway one night and nicked 4 big woven sand bags they use for holding down temporary traffic signs.

Espie now floats perfectly level with no one aboard. So what I'm planning on doing this winter is to make up a weight and balance plan similar to what they do with aircraft. Pick a reference datum and then note down the weight and distance to that datum of every object on board. I intend to use my compression post as the datum. This will give you positive (forward of the post) and negative (aft of the post) moment arms which cancel out. The result is the weight and arm for the entire mess of gear. Once you have this information you can move stuff around and see what it does to the balance. I know that about 50 lbs moved to the foredeck from the cockpit and 200 lbs added to the foredeck gives me balance.

From the original condition I've subtracted 50lbsx120inches (inch pounds) from the negative arm and added it to the postive arm. I've also added 200lbx72inches (inch pounds) to the positive arm. This gives me level. Now I have an idea of how much ballast I need to move from the aft compartment to the most forward area, under the chain locker to duplicate the balance with the water, chain n sand. I know the distances, and as long as the moment arms cancel out I can maintain balance. To change the trim I need to increase the positive arm and decrease the negative arm.

NOTE: this is similar but not the same as an aircraft W&B. With an aircraft you know exactly what it weighs and where the CG is because you physically weigh it at the main gear and nose gear, which are fixed points relative to the datum. You calculate the exact CG from that and end up with a positive or negative number which should fit within the CG envelope in order for it to be balanced. My way just gives you a feel for what the effects of a move are.

Espie has 3 ballast compartments in the keel, all partly full of lead in tin cans. I intend to remove them all, clean out the compartments and then shift ballast until she sits nose down at rest, and more or less level with 500 lbs at the cockpit. This way the forward bunks will be slightly head high and the boat will sail level. And I get rid of the scrap chain, the water can and the sand bags, there by reducing her displacement a tad.

Hope this didn't confuse you all.


Sabre
40 days n a wake up

[rebel heart]

Good idea on the batteries! I can add a few more golf cart batteries on the port side, and that should level me out a bit. We're a bit bow heavy right now as well, so it will be nice to add weight port aft; exactly where my battery compartment is.

[sailvayu]

Funny most of the comments talk about adding more weight to one side. Might be you have too much stuff on the other side. Less weight is usually better in a sailboat.

Wayne Canning, AMS
projectboatzen.com

[Stillraining]

I just tell everybody to switch to drinking the beer from the low side till were level again...