What's the ketch? Adding a mizzen

[pbmaise]

Progress!

My crab claw sail is being recut into a loose footed sliding Gunter lug sail with a modest gaff pole afixed to three track cars.

New Problem!

I no longer need the 42 foot mast, and the boat builder offered it to me at a bargain price. Should I put on the second mast and make my boat a ketch?

Data:

1. Yes I have existing structural support for a mizzen mast.

2. Yes I am concerned that Gunter sail and jib alone will not be enough power to make windward progress. This said, I am a cruising not racing boat and have a 150 HP iron sail. I can buy a lot of fuel for the price of the mizzen, rigging, and sail.

3. The mizzen would add about 300 square feet to my sail plan.

4. I am concerned also about safety. I have no lifelines. However, can require being in harness when working this sail.

5. Intended route Philippines to Japan, Japan to Canada via Hawaii, South to Panama, then up the coast to St Lawrence and Chicago.

What factors should I consider most to justify to ketch or not to ketch?

[pbmaise]

Technically it may be said to be a schooner after adding a mizzen.

This schooner here put the radar on the foremast, and placed the foremast closer to the front. This enabled the much larger Gunter on the mizzen mast.

http://nwmaritime.org/wp-content/upl...-1008x1024.jpg

Unfortunately I do have to contend with an existing radar tower behind the proposed mizzen mast. Either I have to have a boom less than 16 feet long, or move my radar to the top of the main mast.

[Tayana42]

Are you talking about a "Gunter" rig or a "Gaff" rig? The photo looks like a traditional gaff rig to me. I thought a "Gunter " rig was a sliding vertical extension of the mast using a nearly triangular sail.


S/V B'Shert

[pbmaise]

From Wikipedia:

" Gunter-rigged boats are similar, smaller vessels on which a spar popularly but incorrectly called the gaff is raised until it is nearly vertical, parallel to the mast and close adjacent to it. Topsails are never carried on gunter rigs."

My "gaff" is closer to 45 degrees to the mast so I guess you are right it is better to decribe my new sail plan as gaff rigged.

[Tayana42]

Okay, aside from the terminology, you are talking about changing the center of effort of your sail plan and the weight distribution of your rig. Someone with more naval architecture knowledge will have to advise you and hopefully someone with multihull experience. I know some monohull sloops have been converted to yawls or even ketches without moving their main mast location.

With triangular sails you should be able to place your radar on the forward side of the new mizzen mast without interfering with the mainsail (or foresail).


S/V B'Shert

[Rick Williams]

I have to agree with Tayana. Considering how long I've been fiddling with an existing sloop rig to get the balance right, throwing another mast on is like stapling a wing to my car.
Definitely not something you want to do seat of the pants.
I have a ketch because I like the multiple sail plans. Downside is the additional rigging and dacron to be replaced every so often.

[waterman46]

As a ketch owner for 20 years, I am interested in this. You didn't mention the proportions of the proposed mizzen sail area to the new mainsail area. From the 300ft^2 proposed mizzen, it seems you would have a fairly large mizzen proportion to your mainsail. That's a large mizzen to main ratio compared to most ketch rigs. But of course it's not a schooner until the aftermost mast is bigger and becomes the mainmast.

You'll get more power off the wind with your large mizzen, but with your tri do you really want or need this? Upwind performance will not be improved in anything other than light winds, since you'll quickly be overpowered and have way too much weather helm when it pipes up. IMHO if you want this to work upwind you'll have to move the main forward maybe 7 ft, and the mizzen farther forward than you planned.

Bottom line, if you will spend a lot of time sailing in light winds off the wind, it just might be worth the trouble without moving the mainmast. Otherwise like me, you'll probably find the most use you get from your mizzen is a convenient crane to bring heavy items on board (dinghy, motors, etc.), and it's a good place for radar and TV antennas also.

Doug

[Pauls]

No one on this forum is going to be able to give you a quality, meaning accurate and reliable, answer to your question for the very good reason that the information needed isn't available to us. Whether adding a mizzen is a good or a bad idea must be based on an analysis of your boat. Without the data needed for that analysis everyone, including you, will just be guessing.

You can get a little education on the subject and make up your own mind. I'd recommend Dave Gerr's book "The Nature of Boats". It is simple, easy to understand, and written by a guy who knows what he's talking about.

Or hire someone to do the analysis for you.

The cheapest and fastest way to get a job done is to do it right the first time. And that requires knowing what you're doing, and why.

[knockabout]

its not broken

[Scorpius]

The Philippines to Hawaii? Have you looked that one up?

[pbmaise]

Thanks for input.

#1 To a large degree I think I am asking the question prematurely. Certainty, unlike the original rig that I cannot afford to restore, I will not power into the wind at 20+ knots with the small gaff sail. However, if I can make modest progress I will be happy. If I have to burn some fuel it won't hurt too bad.

#2 Philippines to Hawaii is expected to take many months partly because I am expecting poor windward performance, and so have plotted a route via Japan. From Japan, Hawaii is mostly downwind. Then Hawaii to Canada is downwind again. The other reason is I want to stop in Palau, Yap, Guam, Taiwan and So. Korea before reaching Japan.

#3 About the comment about doing something "right" the first time. What most consider to be "right" for my vessel is a big full batton mainsail and a 79 foot tall mast. Afterall, it powers the vessel into the wind fast. In addition to the pocket book issue I can report the original owner was terrified by the power the rig produced. The owners tried and failed to reach Hawaii from the Marshall Islands several times. The errors they made included:

a. Refusing to open the main beyond the third reef because it went too fast for a couple in their seventies.
b. Attempting to reach Hawaii from the Marshals which is too much into the wind.
c. Clearly the largest off the shelf/catalog blocks were too small. Several sets of snatch blocks were aboard when I purchased her. They were all bent and misaligned after overloading.

In other words, despite having the "right" rig, it didn't solve the problem of comfortable cruising.

[Tayana42]

Given the cost constraints you might want to consider junk rig sails also called Chinese lug sails. This could be done with one mast or two.

Advantages are :

1. shorter masts (can be un-stayed)

2. flat cut sails without exotic cloth or design(much cheaper construction)

3. nearly infinite reefing

Perhaps someone with multihull experience or junk rig experience can add to this thought.


S/V B'Shert