Association Forum - theory why the sand bags work

Assn Members Area · Join

Home.

Association Forum

Ships Store

Cruising

Racing

Technical Tips

Photo Gallery - New

Boat Search - Updated

Manuals & Brochures

Swap Meet

Links

Officer Flag Line & Staff

Bylaws & Constitution

Members Area

Join the Association

Notice:
The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.

Association Forum

Username:	Password:
Save Password
Forgot your Password?

All Forums

Catalina/Capri 25/250 Sailor's Forums

Catalina 250 Specific Forum

theory why the sand bags work

New Topic

Topic Locked

Printer Friendly

Author

Topic

Arlyn Stewart
Master Marine Consultant

Member Avatar

USA
2980 Posts

Initially Posted - 12/10/2003 : 21:39:29

I don't recall now who first suggested the sand bags or discovered that they had a redeeming effect on reducing weather helm on the 250... but I recall my initial thoughts being that something was amiss as that was opposite of weather helm theory which usually calls for trimming the stern down to relieve weather helm.

However, since the discovery... dozens or 250s have been described as being trimmed down at the bow with sandbags and enjoying less weather helm in the process.

My own experience was to move 140 lbs of batteries from the aft compartment to the V berth to find that the center board needs less aft trim to avoid weather helm capable of rounding up the boat.

At any rate, I've tried to put words to the reason why the C250 breaks the mold of tradional thought about trimming the bow down.

Enjoy...

http://www.stewartfam.net/arlyn/cause_of_weather_helm.html

Arlyn C-250 W/B #224

N/E Texas and Great Lakes
Arlyn's Sailing Site

Edited by - on

Bryan Beamer
Master Marine Consultant

Members Avatar

USA
1038 Posts

Response Posted - 12/11/2003 : 10:29:30

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"> I don't recall now who first suggested the sand bags<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

I don't know this either. I added weight to my bow about a year before I found this forum, April 2000.

Once again Arlyn you have produced some interesting reading.

Good article. Thanks for sharing.

Edited by - on

gregandcindy
Deckhand

Members Avatar

USA
7 Posts

Response Posted - 12/12/2003 : 19:09:15

Weather helm is something I'm learning about by reading Arlyn's research and then digging into it in other sources. In that I'm picking up 250wk in a month or so, just where should the weight be placed? Arlyn has placed batteries up front in the bilge under the V-berth, but for those of us without batteries, where would sand bags be placed and what amount of weight? Same place, Same weight? Thanks for your help.

Edited by - on

Arlyn Stewart
Master Marine Consultant

Members Avatar

USA
2980 Posts

Response Posted - 12/12/2003 : 19:20:17

Bryan... if you enjoy that kind of reading, you might enjoy this English site... some modelers discuss hull design theory.

Its quite interesting to note that mono hulls can be designed with lifting hull foils to windward when heeling.

http://www.onemetre.net/

Edited by - on

Arlyn Stewart
Master Marine Consultant

Members Avatar

USA
2980 Posts

Response Posted - 12/12/2003 : 19:42:07

Hi Greg,

Welcome to the forum... though with 4 post I may have done that and forgotten.

I think they put it as far forward they can so as to have it as effective as possible to use as little as needed. Various amounts have been offered. I've heard the 300 lb as the upper figure. This may depend on outboard choice.

Enjoy your boat and the National Association and forum...

Edited by - on

Bryan Beamer
Master Marine Consultant

Members Avatar

USA
1038 Posts

Response Posted - 12/12/2003 : 21:04:12

Greg,

Here are a couple of threads out of the archives. These will answer some of your questions.

http://www.catalina25-250.org/forum/topic.asp?TOPIC_ID=860

http://www.catalina25-250.org/forum/topic.asp?TOPIC_ID=2225

Arlyn,

Thanks for the link. It will be this weekends reading.

Edited by - Bryan Beamer on 12/24/2003 16:59:58

Oscar
Master Marine Consultant

Members Avatar

USA
2030 Posts

Response Posted - 12/12/2003 : 21:38:49

Arlyn, read it....makes sense to me.

For those of us who trailer, putting weight up front is detrimental to road stability (increased tongue weight.)

I've come up with a possibly interesting solution. A water tank could be placed up front. Onto what would normally be the "out" line in the bottom of the tank one could hook the vent line of the ballast tank. The vent line of the extra tank would continue to the deck fitting.

If conditions dictated it, this tank would be filled when launching. I think it would at least part ly be above the waterline. Maybe it would need a little help by positioning a few crew members on the front deck for a few minutes to force the bow down and let it fill itself. Or, just stick a hose in there. The tank could be easily emptied with the various air pump arrangements while in the water if desired ...Finally it would automatically empty when retrieving onto the trailer.

If one used a transparent tank one could even calibrate it......If I remember correctly, water is around 8lbs/gallon. So, say 30 gallons, 240 lbs?

I'm researching tanks (triangular?flexible?)....any suggestions?

Oscar

Lady Kay 250 WB #618
Sunrise on the Neuse River...

Edited by - Oscar on 12/12/2003 21:44:34

Arlyn Stewart
Master Marine Consultant

Members Avatar

USA
2980 Posts

Response Posted - 12/12/2003 : 22:25:20

I don't think the water ballast needs as much to balance her lines. I have the wheel and two coaming winches and when cruising carry 11 gal of gas and the 140 lbs of batteries put her on her lines and they are setting just ahead of my water tanks in front of the compression post.

No wheel and coaming winches, I doubt much weight is needed for the water ballast boat... however with your a/c unit, that might be different.

The center board also has the luxury of trimming the CLR with the center board.

The wing keel is the model that has benefitted the most from the sand bags.

Edited by - on

River Harley
Navigator

Members Avatar

132 Posts

Response Posted - 12/14/2003 : 19:39:33

Close to the water tank idea, we obtained several 5 gallon plastic water containers which we filled and placed under the v-berth. Works as well as sand bags, then we have extra water in a pinch (dual purpose).

River Harley

Edited by - on

bear
Admiral

Members Avatar

USA
909 Posts

Response Posted - 12/15/2003 : 07:45:18

Just my two cents, I thought Oscar's idea of PC pipe filled with sand
or lead weight was a pretty nifty thought. Easily removable when trailering and fairly stable when added to the area under the V berth. "Bear" in upstate N.Y. 12" more inches of snow last night and the Weather Channel was even in the area yesterday.

Edited by - on

Oscar
Master Marine Consultant

Members Avatar

USA
2030 Posts

Response Posted - 12/15/2003 : 10:47:13

I also tend to end up with a lot of "stuff" in the MRI chamber when I cruise, especially during the day when sailing, when it ends up being a general dump site so as to keep the floor space and setees clear .

And, I have one crew member that builds a "cave" in the v-berth with lots of stuff, so going in the storage area below is cumbersome......Something "automatic" would be interesting.

Ah, right now it's just "make work" in anticipation of the next sailing mission. Good news there. Due to lack of seniority I was assigned 2004 vacation from the leftover pile....(after everyone else took their picks) Luckily for me I ended up with a week in March that coincides with kids' spring break......Florida charts are on the dining room table!!!!!

Oscar

Lady Kay 250 WB #618

Edited by - Oscar on 12/15/2003 10:50:31

gregandcindy
Deckhand

Members Avatar

USA
7 Posts

Response Posted - 12/15/2003 : 16:24:11

Thanks to Brian and Arlyn for the Info. Could the water tank of the 2003 250wk which is in front of the compression post be considered as a reasonable weight up front, or is it not far enough forward to make a difference? Engine wise, I have a 5hp Honda to push me around for now and I'm not sure of the weight difference between it and the 9.9hp Honda, but I'm guessing there isn't much.
BTW, can I join the Assn. before I own a Catalina 250? I read this forum on a daily basis and feel a bit sheepish asking questions before I've paid my dues to support the cause.

Edited by - on

Oscar
Master Marine Consultant

Members Avatar

USA
2030 Posts

Response Posted - 12/15/2003 : 20:11:55

You are welcome to contribute anything you want, and ask all you want. Especially before buying a boat this is the place to be. Our collective wealth of "oopses and watch-outs" can save you lot's of grief, and will allow you to deal with minor problems in an efficient fashion. We can assemble a check-list for when you take delivery which is built with "decades" of collective experience. Then after you buy you are of course encouraged to become a member.

I have the Honda 9.9, it weighs over 110#. Your 5 should be well beow that. (But could be a little short on oompf on anything other than very sheltered inland water.)
The water tank forward on the newer boats helps, but experience in more demanding sailing conditions has sent some of us scurrying for more......

Oscar

Lady Kay 250 WB #618

Edited by - Oscar on 12/15/2003 20:15:17

Bryan Beamer
Master Marine Consultant

Members Avatar

USA
1038 Posts

Response Posted - 12/15/2003 : 22:02:16

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">Could the water tank of the 2003 250wk which is in front of the compression post be considered as a reasonable weight up front,<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

There is a lot of room in front of the water tank to add additional weight. In IMHO the weight should be added to insure proper balance of the boat. I think most of the wing keels have that 12 gal water tank in front of the compression post. The weight added is above and beyond the weight of the water in the tank.

Edited by - on

cathluk
Admiral

Members Avatar

USA
513 Posts

Response Posted - 12/16/2003 : 21:58:50

Our '97 has the water tank on the starboard side. The placement up front would probably be much better & we may upgrade some day to get a few sandbags out of the front & free up more accessable storage, but its not a high priority at this time.

thanks, Arlyn, for your insight. Very thorough as always.

Edited by - on

gregandcindy
Deckhand

Members Avatar

USA
7 Posts

Response Posted - 12/17/2003 : 17:33:19

Many thanks to Bryan for the threads to former discussions on 250wk weather helm problems. I think I now have a plan for when I pick up the new boat. I'm going to sail her to see if I can overcome weather helm by trimming her correctly-balancing the main with a reef if necessary, trimming the jib for balance, tightening the fore stay as much as is safe, filling the water tank, store the heavy stuff up front of the compression pole, and..........if she stays balanced I'll be happy, if not, I'll add weight. I'll respond with my findings in the summer after we've worked with her for awhile.

Edited by - on

High H2O
1st Mate

Members Avatar

35 Posts

Response Posted - 12/28/2003 : 14:30:26

Just a thought... I've had my 250wb out a few times now but never experienced the weather helm problems discussed in detail in this forum. So, after reading this post, I think I may know why. I realize the water ballast 250s are less prone to the problem and, mine having the second generation rudder helps even more. But here is what I think may be going on with my boat. I bought it in San Carlos Mexico and the previous owner wisely carried ample anchor chain aboard for safety in the Sea of Cortez. The added weight in the anchor locker, I think, is why my boat is very well balanced. So, a practical way to balance a 250 may be to carry extra chain up front.

Edited by - on

reuben
Navigator

Members Avatar

USA
202 Posts

Response Posted - 05/01/2004 : 12:35:07

We splashed yesterday under cold sun in northern Minnesota - most of the powerboats went in the previous day, so it was a gathering of game sailors shaking hands & breathing steam, glad to be craning in after a long winter. At this latitude spring requires faith. I'm exhuming this thread because our 2000 WK appears to need some weight forward, and before lugging unwieldy sandbags up the dock I'm wondering whether anyone's used lead for this job - lead shot or pellets, specifically, in canvas bags, like my Dad used to get for reloading shotgun shells. They'd be a mess if they got loose, but for space effiency they'd be tough to beat. Anyone?

Edited by - on

Al
Captain

Members Avatar

USA
269 Posts

Response Posted - 05/02/2004 : 01:21:50

Lead was my first choice when I wanted to add some weight forward, but it was just too expensive for the amount of weight I wanted to add. I ended up at Home Depot looking at bags of sand and concrete mixes, and found that mortar mix @ 60#/bag was the heaviest. I bought four bags and wrapped each bag with several layers of saran wrap and put them in the compartment under the forward berth. I'm happy with the results. Seems like I slice through waves now instead of the bow bouncing over everything it encountered, while the stern remained steady.

Edited by - on

reuben
Navigator

Members Avatar

USA
202 Posts

Response Posted - 05/02/2004 : 17:52:10

Al, sounds effective - having sunk several dozen fencepost timbers last summer, I should've remembered the weight & density of those readymix bags. Have you had any trouble with them getting wet and turning to 60-lb bricks? Did you really use Saran Wrap, or something like hefty bags?

Edited by - on

Frank Hopper
Past Commodore

Members Avatar

Pitcairn Island
6776 Posts

Response Posted - 05/02/2004 : 18:40:07

If they do set, they will set to the shape of the hull; what could be better?

Edited by - on

Alan Therrien
Navigator

Members Avatar

USA
113 Posts

Response Posted - 05/02/2004 : 20:00:17

Another option to consider for bags of weight can also be found at Home Depot for about $3/bag - marble chips. They come in small bags that weight about 50 lbs, and will be much easier to deal with if the bag splits open.

Alan Therrien
"Moonpenny"
C 250 K #418

Edited by - on

Al
Captain

Members Avatar

USA
269 Posts

Response Posted - 05/02/2004 : 20:36:21

I tried plastic bags first, but it made them too slippery and hard to handle. The saran wrap, stretched tightly, makes them as small as they're going to get, and makes them "sticky", so they don't slide around, since they're all touching each other. I figured if they got wet and "set", that would be a bonus, since now if one got punctured, nothing would spill out.

Edited by - on

Topic

New Topic

Topic Locked

Printer Friendly

Jump To:

Association Forum

Notice: The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.