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  #76  
Old 10-03-2009, 10:30 AM
wardd wardd is offline
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does it float?
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  #77  
Old 10-03-2009, 10:42 AM
welder/fitter welder/fitter is offline
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SFO, others,
I bought a Mac26S(swing keel, water ballast) a few months ago. I needed a boat that I could ship in a container to Asia, not an easy animal to find. As well, I needed a boat that could be beached or easily removed from the water without the expense/availability of a lift. Until I ship it to Asia, in the near future, I am not paying for moorage. My experience has been that this model is faster than the newer versions, when sailing. It is extremely important to take on the correct amount of water ballast. If you can touch the surface of the water with your finger, through the inspection hole, your good. Just remember to put the plug back in, or you'll be mopping up! With the proper amount, the boat feels a bit tender to a certain point of heel - especially for one who is used to larger and/or heavier boats - but stiffens up nicely. Not a bad turn of speed with the basic sail rig, but I'm looking forward to adding a spinaker and a main with reef points. With the standard Mac rudder, one does experience weather helm, but there are alterations one can make and "Idasailor" sells a modified rudder.

I took it out in some stronger winds the other day(30+kts) and thought I'd made a foolish move, but the boat handled well. My wife is returning soon & I expect her to feel the same initial nervousness, as she is used to our old Cal330, but I believe that she'll be comfortable after a couple of hours & I know she'll appreciate the simplicity of the boat systems. San Fransisco has, on average, more challenging sea/wind states than our area. Maybe you can hook up with an owner down there & experience their boat before you make the financial commitment to buy?
Best of luck!
Mike
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  #78  
Old 10-04-2009, 02:16 AM
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I hope you enjoy the boat WF. It should do all you hoped it would.

The 26S must be one of the older designs (2003 was the start of the 26M, and for 7 years before that, the 26X - swing keel, water ballast.)

The latest 26M would be a faster sailer as well as a faster motor boat -
the sailing has been enhanced with taller rig, reduction of the drag from the centerboard trunk, and the rotating mast

In any case, the optimum sailing angle is about 6 degrees - flat like a laser.
That truly is totally different to the majority of keel boats.

Do keep up the story as you go, please
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  #79  
Old 11-16-2009, 04:58 PM
ancient kayaker ancient kayaker is offline
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Voice in the Wind

Just read the thread for the first time. It is what I call a happy thread. People who have a M like it and the best thing that people who do not can say about is "yeah sure, it's OK but it's not for me."

Everyone gets what they want and likes what they have. Nice!

It's great to see folk tolerant of differences like this. There are other threads that are not so happy; they tend to discuss high-testosterone boating activities and I don't want to attract unfriendly fire so I won't be dumb enough to name any. Perhaps the laid-back, relaxed nature of the M rubs off on folk.

I'm not really happy with any boat that's bigger than I am so I'll just tuck it under my arm and and sneak quietly out the back.
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  #80  
Old 12-01-2009, 12:48 PM
powerabout powerabout is offline
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I actually sailed on one a few months ago in flatish water with about 15-18kts.
3 guys on board
My observations;
Driver got soaked at the helm while motoring due to the flat hulls sides.
Sailing
Rotating mast will not rotate on tacks.
Driver trying to helm a yacht with a 14" wheel whilst also turning the tilted outboard is a job for the incredible hulk
Keel too small for the above wind speed so massive leeway
Boat design doesnt allow the crew weight to help the righting moment as you cannot get your weight anything more then halfway from centerline to hull extremity once healed.


My Opinion
Was a brilliant marketing idea to build a concept.
Selling a vessel in a unique category ( the concept) allows the builder to supply rubbish fittings as know-one will be comparing them to another boat.
It will also keep the price down and help sell the concept.
Rigging,sails and deck hardware were of a very poor quality of unknown brand
Once an owner loves his boat he will replace all the stuff without saying anything.
The rotating mast on a low performance yacht is laughable.
Using a mast section so old fashioned and rotating it even more laughable.
The rigging is not designed for a rotating mast
The steering connection to the outboard is plain dangerous and could not be ABYC or USCG approved so I dont know how they sell that in the US
( I sailed one delivered new in Asia)

I think the concept would be acceptable for 2 people on a small lake where there is flat water the wind never goes over 10kts
The whole rigging could be better which would make the sailing part better.
Reefing from the cockpit would make life much easier as 15-18kts ( guess) it was way overpowered.
The steering could be improved probably by going hydraulic and then you could disconnect the outboard while sailing.
Add a heavier keel
(One here was sunk by poor operation but hey you can sink a J24 (in big wind) as well.)

Boating is meant to be fun
Each to his own.
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  #81  
Old 12-04-2009, 04:37 PM
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rwatson rwatson is offline
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Quote:
Originally Posted by powerabout View Post
I actually sailed on one a few months ago in flatish water with about 15-18kts. 3 guys on board My observations;.
That would be a good test scenario, as I figure that is a desirable yacht operation range.

Quote:
Originally Posted by powerabout View Post
Driver got soaked at the helm while motoring due to the flat hulls sides.;.
Well, yes, it IS a yacht. The splash line does help somewhat in calm water. The only solution would be to do some kind of bow overhang, but this would be inneficient for sailing. On really flat water, the splashing is not a problem. On more lumpy water, I devised a radical way of avoiding splash - I slowed down.
On other days I put up the non-factory spray covers.

Quote:
Originally Posted by powerabout View Post
Sailing Rotating mast will not rotate on tacks.
I havnt tried the rotating mast on macs, but it doesnt surprise me. Most rotating masts dont! see the discussion at rotating mast stay attachment

and that includes some supposedly more 'proper' sailing boats.


Quote:
Originally Posted by powerabout View Post
Driver trying to helm a yacht with a 14" wheel whilst also turning the tilted outboard is a job for the incredible hulk
Well, that is on that boat. Most Macs are shipped without motors, and dealers fit and set them up, often in the country they get exported to. The skill and expertise of the dealer is the controlling factor for ease of use. This steering problem rarely gets reported in Mac Forums - so your friend can be assured that he doesnt have to put up with it.

Besides, on all the Macs I have seen ,you can detach the motor linkage when sailing, to reduce any heavy motor effect.

Quote:
Originally Posted by powerabout View Post
and the Keel too small for the above wind speed so massive leeway
Well, no. If you have got massive leeway, you are not sailing it correctly. Its like saying you get massive leeway on a Laser sailing dinghy (similar hull configuration) - it means you have the sails in too tight. The optimum heel of a Mac is only 6 deg, anything over that, and you will not go any faster. They are not designed as a hard on, 20 degree blue water racer. Once the wind starts to heel the Mac past 6 degrees, you either head up, or vang on, and ease the mainsheet. The boat will take off with the lift from the airflow and stop heeling.

Quote:
Originally Posted by powerabout View Post
Boat design doesnt allow the crew weight to help the righting moment as you cannot get your weight anything more then halfway from centerline to hull extremity once healed.
see previous comment, but yes, its hard to 'hike out' on a Mac.


Quote:
Originally Posted by powerabout View Post
My Opinion
Was a brilliant marketing idea to build a concept.
Selling a vessel in a unique category ( the concept) allows the builder to supply rubbish fittings as know-one will be comparing them to another boat.
It will also keep the price down and help sell the concept.
Rigging,sails and deck hardware were of a very poor quality of unknown brand
Once an owner loves his boat he will replace all the stuff without saying anything.
Absolutely - the concept is built by cheap mexican labour, and the dealers fit any old rubbish. Most long term Mac owners have completely rejigged their boats, and chucked out the original factory fittings even before they broke

Quote:
Originally Posted by powerabout View Post
The rotating mast on a low performance yacht is laughable.
Using a mast section so old fashioned and rotating it even more laughable.
The rigging is not designed for a rotating mast
Any rotation is desirable - expecially in very light airs. I dont know how you can say that mast rotation is only for high performance boats.

Not only is the rigging designed for rotation, Roger macgregor took out a patent on the concept. It may not be perfect, but it is miles ahead of other boats in the same class.

Quote:
Originally Posted by powerabout View Post
The steering connection to the outboard is plain dangerous and could not be ABYC or USCG approved so I dont know how they sell that in the US ( I sailed one delivered new in Asia)
Once again, a dealer problem, but you would have to make a much better case than your opinion to justify the "plain dangerous" accusation


Quote:
Originally Posted by powerabout View Post
I think the concept would be acceptable for 2 people on a small lake where there is flat water the wind never goes over 10kts
Well, you should back track a few posts in this thread, and get on to the website of the guy who travelled up a nd down the West Coast of the US. That should convince you.


Quote:
Originally Posted by powerabout View Post
Add a heavier keel (One here was sunk by poor operation but hey you can sink a J24 (in big wind) as well.)
It would solve nothing - I have never heard of a Mac sinking, only being knocked down. A heavier keel would be a disaster for this type of design.

Quote:
Originally Posted by powerabout View Post
Boating is meant to be fun Each to his own.
Hell yes, so true. No such thing as a perfect boat, just one that does what you want it to do.

Often the transition between disparate types of boats is hard for a skipper, so it takes time to appreciate and control the beasts properly.
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  #82  
Old 12-04-2009, 09:01 PM
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jimm jimm is offline
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All the above mentioned attributes of the m26' are on target. I guess the question is. Do you want to sail a boat that returns to you the full feeling of sailing? Only an efficient sailboat can return that feeling. There are many out there that can do it. M 26 is not in the running.
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  #83  
Old 12-04-2009, 10:22 PM
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As to water ballast. I have used it in the hollow keels of a 16' design with dual keels with a hole at the top and a hole at the bottom allowed the keels to fill quickly and empty slowly. 75 lbs per keel@62lbs per cu ft fresh water,64lbs per cu ft salt. results sailing response was slower. moment of inertia being slowed by the added volume of material(water). 150 lbs is considerable in a 16 ' boat but it is important to understand that until the ballasted water rises above the water line it provides 0 righting ballast.
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  #84  
Old 12-06-2009, 04:32 AM
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rwatson rwatson is offline
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Quote:
Originally Posted by jimm View Post
As to water ballast.150 lbs is considerable in a 16 ' boat but it is important to understand that until the ballasted water rises above the water line it provides 0 righting ballast.
Water ballast will never compete with "proper" ballast in many ways, but it does have some huge advantages.

By the way, water ballast will never rise above the water line, unless pumped, and very few do that. The boat will lower itself as the water comes in of course.

I dont have the stability calcs the Macs, but I do have them on the first version of my current project. The attached calcs show 150kg, of fixed ballast, and 500 kilos of water (the beam and weights are very close to the Mac)

Notice from the attached cross section, the ballast is up to the waterline only. Ballast above the waterline will reduce righting moment, not increase it.

At 66 degrees, you have 450 kilos of righting moment, and 100 kilos of righting moment at 115 degrees.

Thats pretty impressive for a "standard" yacht, let alone water ballasted.

The Macs at
http://www.macgregor26.com/safety/safety.htm
are pictured being held down with the mast horizontal to the water, and it still has 50 kilos of righting moment.

Now, as far as a proper yacht 'feel', I have sailed in more traditional boats as well, The comfort of tonnes of lead ready for any blow is handy in 'big water', but these boats are designed to sail with 10-15 degrees of heel. Thats a very uncomfortable angle.

Where the "proper yacht feel" gets really uncomfortable, is when you have to drag the boat out of the water with permanent ballast and a deep keel. You see dozens of these boats sitting around the marinas, mostly unused and for sale. They are just too much hard work. I see Macs heading up and down the highway being towed by avergae 4wd's, to many and varied spots.

The "Mac Concept" is different to traditional yachts, and fulfills a different role - and the raising and lowering of the centeboard can be done by a slim, non muscular georgeous bikini clad thing, and doesnt require your 200 pound ex footballer mate who can only get out sailing every 6 months.

You get my drift :-)
Attached Files
File Type: pdf 080724_28trail_stability_curves.pdf (263.3 KB, 178 views)
File Type: pdf 080811_28'trailablePRELIM_sht3of3.pdf (114.0 KB, 152 views)
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  #85  
Old 12-06-2009, 06:19 AM
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Guillermo Guillermo is offline
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Quote:
Originally Posted by rwatson View Post
Ballast above the waterline will reduce righting moment, not increase it.
Just popping up to friendly say this statement is not true, generally speaking. Asuming you're talking righting moments at small angles and there are small -or negligible- increased free surfaces, it will depend on the amount of ballast added and the relative position of its CoG against the CoG of the whole boat before such adding.


Cheers.
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  #86  
Old 12-06-2009, 09:33 AM
ancient kayaker ancient kayaker is offline
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Just another correction while we are doing that. Water ballast is sometimes regarded as a quantity of water attached to the hull, giving rise to the statement that it does nothing until part of it raised above the waterline.

This isn't really true. The water is carried inside the hull. Any added weight low down and inside the hull is ballast, although there are more effective substances than water. Admitting the water does change the stability properties of the hull. In addition it adds mass which is helpful when changing tack but reduces acceleration, and often speed.

It is not possible to accurately compare a water-ballasted hull with an unballasted hull because the cavity for the water, which has considerable volume, changes the shape of the hull. Apples and oranges; we all know this.

I am considering adding a little water ballast to my small sailboat, in the form of several water bottles. Once the water thaws out in these parts, that is! I don't expect to gain much in sailing performance, if at all. My objective is to give the little hull a bit of extra mass; because the hull is only 60 lb moving around is a bit like standing on a skate board.
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  #87  
Old 12-06-2009, 11:03 AM
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Guillermo Guillermo is offline
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Quote:
Originally Posted by ancient kayaker View Post

...... because the cavity for the water, which has considerable volume, changes the shape of the hull.
?????????
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  #88  
Old 12-06-2009, 03:55 PM
ancient kayaker ancient kayaker is offline
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I meant that, because such a large volume of water has to be accommodated inside the hull for water ballast to be effective, the hull shape must be different.
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  #89  
Old 12-07-2009, 02:25 AM
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rwatson rwatson is offline
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Quote:
Originally Posted by ancient kayaker View Post
I meant that, because such a large volume of water has to be accommodated inside the hull for water ballast to be effective, the hull shape must be different.
... and I guess if the hull sails lower, the underwater 'shape' of the hull will be quite different.
Quote:
Originally Posted by Guillermo
"Ballast above the waterline will *reduce* righting moment, *not *increase it.
---End Quote---
Just popping up to friendly say this statement is not true, generally speaking. Asuming you're talking righting moments at small angles .
Generally speaking, and small angles ... fair enough.

I suppose I could have been totally honest and said "any weight above the keel line" -

Actually, after re-reading, I think I misinterpreted the original statement, which was
Quote:
Originally Posted by Jimm
until the ballasted water rises above the water line it provides 0 righting ballast..
Which is somewhat different to placing water above the waterline which I took it as - apologies Jimm.

I will have to leave the elucidation to more expert opinion, but you may have something there Jimm.

All education on the water ballast thing greatfully accepted.
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  #90  
Old 12-07-2009, 10:56 AM
ancient kayaker ancient kayaker is offline
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These calculations are rather arbitrary but perhaps they will serve to illustrate the potential for improvement using water ballast.

Using arbitrary units:
Boat A: displacement 1, stability 1, cost 1, unballasted (towing weight = displacement)
Boat B: based on design of boat A with 10% more beam and draft, same rig, motor and accommodations, water ballasted as required for necessary displacement increase. Displacement 1.21, stability 1.33
towing weight estimate:
bare hull weight of boat A estimated 0.5
Bare weight of boat B = 0.5 +10% = 0.55
Ballast tank and hull reinforcement = 0.05
Rig, motor, accommodations as boat A: 0.5
Total towing weight less ballast = 0.55 + 0.05 + 0.5 = 1.1
Cost 1.1
Boat C: downsized version of boat B; same towing weight and cost as boat A.
Downsizing scale factor 0.968
Total towing weight = 1.1 * 0.968^3 = 1, cost 1, stability = 1.33 * 0.968^3 = 1.21

Because they have the same approximate towing weight and cost, boats A and C can be compared. Approximately 21% stability improvement from using water ballast.

Notes:
1. I have assumed same cost/unit weight for all 3 boats.
2. Water ballast benefit is greater since ballast can be carried below the unballasted boat’s CoG, this factor not taken into effect so the estimate is conservative.
3. Boat C is shorter and beamier so its performance will be reduced compared to boat A.
4. Adding more sail area to equalize the performance of boats A & C probably cannot be done for the same cost.
5. Boat C would have less internal space than boat A due to the ballast tank.

In practice simply scaling an unballasted hull design would not be the best approach. However, for a simple example it illustrates the point and highlights some of the trade-offs.

Obviously a denser ballast substance would be more effective, and equally obviously there would be a cost impact, especially if the ballast were dumped into the water to reduce towing weight!
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