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ausnp84 · 26-09-2015, 04:29

Hey guys and gals,

Has anyone out there re-masted a yacht before with a different mast / increased their sail plan significantly?

We have a steel schooner that is severely undercanvassed (80sqm / 15t) and I'm in the process of converting it to a 120sqm ketch, but would be interested to get any advice / info from someone who's done it before.

Give me a shout if that's you....

n

Snowpetrel · 26-09-2015, 05:13

Wow, youve done a ton of work on the boat so far, looks good! If it where me, id be thinking about a cutter, getting rid of the mizzen is going to help stability no end. If you are going to stick with the ketch, give some thought to filling in the gaps between the mast, otherwise it looks like the main is going to be very tall and narrow. Not ideal for the sort of brute power you need to push her along. Id probably get rid of the backstay and go a big roach main. Or do something like a wishbone ketch. A longer bowsprit also helps.

With the scooner rig, ive sailed a staysail schooner, we used a big fisherman staysail in light airs. Worked pretty well.

Have you got a sail plan?

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ausnp84 · 26-09-2015, 06:01

Thanks! It's so great to be finally out cruising again after so long building.

Here's a pic of the sailplan currently with some rough measurements against it:

Personally, I really like the idea of a cutter-rigged sloop - easy to setup and get sailing, less rigging to worry about, etc etc

On the flip side, if we ditch the mizzen we have to seriously think about moving the foremast aft which will mean reconfiguring the salon, moving the compression post, etc.

I like your idea on the fisherman - we met a couple on a Nauticat 44 schooner with a huge sailplan, including multiple spinnys, a blooper and a huge fisherman. They seemed pretty happy with the performance of their heavy cruiser, so it's definitely an option for us.

nathan

Snowpetrel · 26-09-2015, 06:23

Whatever you do its going to be an expensive exercise, what with new sails and all. So you want to do it right first time, or work out how to cheaply improve what youve got.

Eg working with what youve got, id lengthen the bowsprit, add a bumkin or strong davits to extend the backstay aft. Then swap the main to the mizzen. And get a big roach mainsail, maybe a cutdown secondhand multihull main.

If you go a new mast, it might just be worth bighting the bullet and going a cutter. Yes the mast will need to move aft. So will chainplates, but its going to be the best way to get her really sailing well. The real problem is that the mizzen/main is a long way forward. This is always going to limit your sail area. Most traditional ketches have the mizzen overhang the stern a good way.

Also, small point but normally when calculating sail area just use 100% of the foretriangle, rather than the combined totals of the genoa and staysail. That way you get a better comparision with other designs. Id be aiming for a Sa/disp around 15 for that boat. But with the fin keel, and good light sails you might be able to sneak it down to 13 and still sail Ok. Ideally 17 -20 for a heavy boat is nice but you need the stability to carry the sail otherwise you find yourself reefing very early.

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ryon · 26-09-2015, 06:48

How about adding a topsail? Like squares are where it's at, daddy-o!

Panope · 26-09-2015, 06:54

I will echo SnowP's idea of going with a single mast. I converted Panope from schooner to sloop for the purpose of reducing weight aloft, reducing windage, shortening LOA, reducing the number of parts and removing the main mast from the middle of the saloon. Current mast is slightly taller than the old mainmast and is stepped in the fore mast position. Bowsprit is gone.

I use a gaff main with nearly the same luff as the old schooner main. In order to maintain balance and sail area, I used a much much longer boom and gaff. The main is a monster (45sqm) but once reefed it is quite manageable. I am able to single hand fine.

My working sail center of effort did move up about 1.5 feet. Boat is a bit more tender now. However, I also added a lot of weight high on the hull (pilothouse) so not sure if the tenderness came from the higher sailplan or a (possibly) higher vertical center of gravity.

Boat sails noticably better now in winds up to 15 knots. In moderate winds, the two rigs sail similarly. In winds over 25 knots, the schooner rig sailed better. Boat handles much better now under power in high winds as the old rig had a ton of windage that would cause the bow to be "blown off" when maneuvering or docking.

I should also mention another motivation for making these changes: I like to tinker with stuff.

Steve

**HappyMdRSailor** · 26-09-2015, 06:57

Quote:

Originally Posted by ryon

How about adding a topsail? Like squares are where it's at, daddy-o!

HAHAAAAAAA!

AWESOME RYON-COOL-CAT!

ausnp84 · 26-09-2015, 07:04

Quote:

Originally Posted by Snowpetrel

Also, small point but normally when calculating sail area just use 100% of the foretriangle, rather than the combined totals of the genoa and staysail. That way you get a better comparision with other designs. Id be aiming for a Sa/disp around 15 for that boat. But with the fin keel, and good light sails you might be able to sneak it down to 13 and still sail Ok. Ideally 17 -20 for a heavy boat is nice but you need the stability to carry the sail otherwise you find yourself reefing very early.

Sent from my GT-P5210 using Cruisers Sailing Forum mobile app

So when working out my SA/D, I should only use 100% my foretriangle area? Or use only use that figure when comparing to other boats?

Currently, we're about 11.8SA/D and in anything under 15kts, we struggle to get 3kts (and subsequently end up motoring). Above 25kts tho, we'll happily hammer along at 7. If we can get a SA/D of 17 I'll be happy.

Panope - thanks for your thoughts. An option we have is for a 16.7m mast (increased from our current 11m foremast) with a 5m boom. My only concern with the sloop is balance - having a mizzen will allow us to balance the boat for lee / weather helm, whereas just running as a sloop will mean we run the risk of turning the boat into a real dog (unless we engage a naval architect to do the sums, in which case this project starts getting silly expensive).

n

Panope · 26-09-2015, 07:23

Re: sail balance. Keep in mind that if you go with a taller main, the center of effort will move up AND to leeward thus increasing weatherhelm. It might be that the boat would balance fine without the mizzen.

I redesigned my rig by the seat of my pants and I got pretty close with balance. I actually ended up with slightly more weather helm than desired. Remarkable given that I removed the larger and aftermost mast.

I have since learned that for even naval architects, sail balance is more art than science.

Steve

ausnp84 · 26-09-2015, 07:33

Thanks Steve! That's really helpful and gives us options.

We're in a boatyard that is very cheap for mast movements, so we could fit the taller mast in the position of the foremast, keep the existing boom (3.7m - as opposed to chopping down the new 5m boom) and see how it goes.

If it's all good - great! If not (and it looks like removing the mizzen would help the balance), we could then pull the mizzen, fit the longer boom and fit a big, roachy main. And see how it goes.

n

Panope · 26-09-2015, 07:36

Sounds good. You will learn more from test sailing an idea than all the naval architecturing in the world.

Steve

Jolly Roger · 26-09-2015, 07:41

I went the other way and converted a ketch to a brigantine schooner. You might gleen some insight by reading my re-rig pages, at Schooner Britannia, renovation of a Brigantine Schooner.
JR

ryon · 26-09-2015, 07:56

Quote:

Originally Posted by Jolly Roger

I went the other way and converted a ketch to a brigantine schooner. You might gleen some insight by reading my re-rig pages, at Schooner Britannia, renovation of a Brigantine Schooner.
JR

That's the idea! But where's the top-yard? Your avatar has a top, but the photo only shows a course.

Terra Nova · 26-09-2015, 09:45

You're trying to turn a motor-sailor into a sailboat by over-canvassing her. This can't end well.

You could increase your existing sail area with a few more sails. But you'll never make that boat a sailboat.