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You could also balance the boat by stowing a lot of heavy stuff above the water line. Can't see that it would have been hard to mimic the arm and weight of the mast by lashing a bunch of jerrycans with water on both sides mid ship for example, or on top of the cabin.
 

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You could also balance the boat by stowing a lot of heavy stuff above the water line. Can't see that it would have been hard to mimic the arm and weight of the mast by lashing a bunch of jerrycans with water on both sides mid ship for example, or on top of the cabin.
I'm no expert on physics, but that seems counter intuitive to me. I had thought that a sailboat mast prevented rolling only by the force of wind on the sail, but more knowledgeable folks here convinced me otherwise, one post in particular by making the reference to an ice skater who spins fast with arms tucked in and slows with arms extended. From my limited research this has to do with "rotational inertia" and "angular momentum". This article explains the phenomenon.

http: // www .bsharp.org/physics/spins

Under this principle, simply adding weight on deck wouldn't help, you'd have to add weight aloft to get the increase between the "axis of rotation" and mass, increasing the "moment of inertia."

The effect apparently depends on the amount of mass and the distance it is away from the center of axis. Thus, having a top heavy mast would apparently reduce the speed of roll compared to a lightweight carbon job, which would allow for faster roll.

Again, sounds counter intuitive to me, but consistent with the posts of more knowledgeable and experienced members.

But I have a cat so all this is irrelevant to me.
 

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Another thought I had thinking about this rotational inertia stuff.

If putting mass further way from the center of rotation dampens the effect of spin, i.e. putting a mast on a boat, then by the same logic, wouldn't putting heavier weight at the ends of the boat, as opposed the middle of the boat, dampen the effect of pitching?

Maybe some of your physicists here can answer that question.
 

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I know this is an old thread but thought I would reply anyway.

I had thought of something like this and have read a few articles where some folks have actually done it. I recently bought a Mac 22 and with this boat there is no need to make any changes. It's small enough to add a mast stepping system and with the swing keel I can raise/lower the keel to suit my needs. Raise the mast for stability while motoring or sailing, or leave it stored across the cabin. If you plan on extensive cruising the 22' would be a bit (well, more than a bit) small. Which makes me wonder, what would be the maximum size sailboat that a mast stepping system would be practical?
 

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I know this is an old thread but thought I would reply anyway.

I had thought of something like this and have read a few articles where some folks have actually done it. I recently bought a Mac 22 and with this boat there is no need to make any changes. It's small enough to add a mast stepping system and with the swing keel I can raise/lower the keel to suit my needs. Raise the mast for stability while motoring or sailing, or leave it stored across the cabin. If you plan on extensive cruising the 22' would be a bit (well, more than a bit) small. Which makes me wonder, what would be the maximum size sailboat that a mast stepping system would be practical?
as the owner of many different boats throughout my life, I can shed some reasonable light on this.

its really not a worry for those that want to remove the mast from a sailboat and use the hull as a cruiser only... there definitley are pros and cons, but for the most part, thru this entire thread it has been about how rolly the sailboat would be in a seaway without the mast, and, yes it is a fact.... but not so much that it is unbearable like so many "swear" it is.
these people have obviously never been aboard a powerboat in a choppy seaway....
my point is, they are comparing a sailboat without a mast to a sailboat WITH a mast, so yes, they are correct. but when comparing the mastless sailboat to a powerboat, the sailboat is more stable.... a 30' powerboat bobs like a cork, but can sink like a rock when inverted... at least the mastless sailboat will return upright.

as for trawlers, they CAN ride better because some of them DO have a shallow, but weighted keel... and all of them are designed to be as stable as possible, but for a man on a budget as most who would consider doing this is, a trawler is out of the budget.

and it IS true that a sailboat is quite a bit more fuel efficient than an equivalent powerboat.... and boats in the 28 to 32ft range, all have about the same storage space available... when they start getting bigger, the powerboats do begin to have larger spaces to store stuff.

for those that think one could by an old powerboat and put a smaller engine in it to gain the fuel economy... this is not very well thought out statement.
powerboat hulls do NOT slip thru the water as easily as a sailing hull does... and by the time one gets done repowering/modifying the powerboat hull in an attempt to make it as fuel efficient as the sail hull, the sail hull will can be thousands of miles away, with money still in the kitty.....

I am also a firm believer that all things being equal between a smaller "budget" sailboat and the traditional style "budget" powerboat, a sailboat is a more comfortable home for long term cruising....
And, if I was out somewhere in the ocean broke down, where help may be days or weeks away, I would much rather be in a mastless sailboat, than I would in a traditional powerboat... because during a storm, it is safer even if you only take a minimal amount of care.

trawlers are not included in this assessment because I believe that anyone considering doing this is working on a tight budget...

even if it does go against the grain of what most people want to believe, it can be a very economical way to go boating... but one should consider the reasonable pros and cons, not the unreasonable ones....
 
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as the owner of many different boats throughout my life, I can shed some reasonable light on this.

its really not a worry for those that want to remove the mast from a sailboat and use the hull as a cruiser only... there definitley are pros and cons, but for the most part, thru this entire thread it has been about how rolly the sailboat would be in a seaway without the mast, and, yes it is a fact.... but not so much that it is unbearable like so many "swear" it is.
these people have obviously never been aboard a powerboat in a choppy seaway....
my point is, they are comparing a sailboat without a mast to a sailboat WITH a mast, so yes, they are correct. but when comparing the mastless sailboat to a powerboat, the sailboat is more stable.... a 30' powerboat bobs like a cork, but can sink like a rock when inverted... at least the mastless sailboat will return upright.

as for trawlers, they CAN ride better because some of them DO have a shallow, but weighted keel... and all of them are designed to be as stable as possible, but for a man on a budget as most who would consider doing this is, a trawler is out of the budget.

and it IS true that a sailboat is quite a bit more fuel efficient than an equivalent powerboat.... and boats in the 28 to 32ft range, all have about the same storage space available... when they start getting bigger, the powerboats do begin to have larger spaces to store stuff.

for those that think one could by an old powerboat and put a smaller engine in it to gain the fuel economy... this is not very well thought out statement.
powerboat hulls do NOT slip thru the water as easily as a sailing hull does... and by the time one gets done repowering/modifying the powerboat hull in an attempt to make it as fuel efficient as the sail hull, the sail hull will can be thousands of miles away, with money still in the kitty.....

I am also a firm believer that all things being equal between a smaller "budget" sailboat and the traditional style "budget" powerboat, a sailboat is a more comfortable home for long term cruising....
And, if I was out somewhere in the ocean broke down, where help may be days or weeks away, I would much rather be in a mastless sailboat, than I would in a traditional powerboat... because during a storm, it is safer even if you only take a minimal amount of care.

trawlers are not included in this assessment because I believe that anyone considering doing this is working on a tight budget...

even if it does go against the grain of what most people want to believe, it can be a very economical way to go boating... but one should consider the reasonable pros and cons, not the unreasonable ones....
+1

Was about to say pretty much the same thing but you beat me to it. Although it may seem impractical and maybe even backwards to the typical sailor, to someone on a budget and willing to think out of the box, this can work quite well provided you are aware of the pros and cons.

For more practicality though, I would recommend using it as a motorsailor if at all possible. Motoring 100% of the time means either large tanks of gas and/or making more frequent stops to refuel. As a motorsailer you could significantly increase your range and save some money overall by keeping the rig.

If the issue is not wanting to learn the intricacies of sailing but still wanting to go this route, you may want to research which sailboats would be most accommodating for what you want to accomplish and in the manner you wish to accomplish it.

Sent from my LG-H918 using Tapatalk
 
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