Turning a Ketch into a Cutter

[SKG56]

This maybe a stupid question but I'm going to ask it anyway, has anyone ever heard of someone turning a Ketch into a Cutter, if so, was the result a positive one

[Don C L]

Never heard of it. Yawl, maybe. The problem is that the rig's center of effort is designed to match correctly with the hull's center of lateral resistance. To eliminate the mizzen without moving the main aft would leave the CE too far forward. There is also the issue of sail area. To maintain it you'll need a taller rig and that may not match well with the ballast. If it's designed to be a ketch, better leave it that way, IMO. Were you looking to do it with your own boat?

[El Pinguino]

Westerly Sealords, same same my boat, could be ordered as either a sloop or a ketch. Only a few were built as ketches. Likewise her little sister the Corsair could also be fitted out as sloop or ketch.
All Sealords including mine have the plinth just aft of the centre cockpit for mounting the mizzen mast.
The obvious difference is that the boom on the sloop is some 2 feet or so longer. The mast is in the same position on either and appears to be the same length as the airdraught is the same for both at 56 feet.

Sail areas..

Main (sloop) 352 sq ft, (ketch) 274 plus Mizzen 108 sq foot.
Genoa (sloop) 615 sq ft, (ketch) 592 sq ft.
#1 Jib (sloop) 352 sq ft , (ketch) 325 sq ft.


Sealord ketch here .. 1984 Westerly Sealord 39 Sail Boat For Sale - www.yachtworld.com

The main sheet traveler is in exactly the same position on both... this is identical to my set up... except for the extra mast..

So yes.. it can be done.. don't know why you would bother though. Maybe just need a longer boom and bigger main...

[Don C L]

Huh, well, perhaps I stand corrected!

[Panope]

I converted Panope from a schooner to a sloop by removing bowsprit, removing the main mast and placing it in the foremast position. Boom and gaff were lengthened considerably. Working sail area unchanged. Sail center of effort same in fore/aft direction. Center of Effort moved upward about 1.5 feet.

Given that the mizzen sail area of a ketch is a small percentage of total sail area, the ketch-into-cutter modification should be MUCH easier to accomplish than the schooner-into-sloop modification (where the removed mainsail accounted for about half of the working sail area).

On my boat, the sailing performance between the two rigs is very similar. I'll say that the sloop rig performs slightly better in light air and the schooner slightly better in heavy air (Lots of other major modifications were accomplished simultaneously so my before/after comparison may be flawed).

Steve

[StuM]

If you're converting it into a real cutter, you would probably want to move the main mast back as well. Not a trivial exercise.

[ausnp84]

I guess the question is.... why? Do you want a more manageable headsail plan? Do you just never use the mizzen? What boat are you thinking of doing this to?

n

[SKG56]

The boat I'm talking about is the Allied Seawind MK II, they were built as both a Ketch and a Cutter, they are the same boat, the main mast appears to be in the same spot on both boats, it would seem to me, after verifying this, you could match the boom that's on the Cutter, Am I wrong about this

[ausnp84]

Ah ok, that's a bit easier then. I'm guessing you mean these two versions of the Allied Seawind?

It looks like the cutter used a longer boom and corresponding larger mainmast, but see if you can find a forum or group to confirm that.

n

Cutter



Ketch

[SKG56]

I wanted to get the mast out of the cockpit, let me be clear, I don't own the boat yet, I owned an Allied Seawind 30 Cutter, but had to sell because I could not get to it, I could wait till I see a MK II Cutter I like, there is one available, but it's not near the boat that this Ketch is,

[Littlechay]

I know of a few people who have done it. The traditional arguments for a ketch (smaller spars, easier to handle sails etc..) have more or less disappeared with modern sail handling devices and roller headsail furling.

As other posters have pointed out not all boats are built alike but many production boats were and were offered with a choice of rigs. Also as others have pointed out it can be simply a case of throwing away the mizzen and putting on a new mainsail and boom.

Get more opinions from proper rig designers too though

Chris
--
Tweed's World | A high latitude sailor preparing for tropical cruising

[StuM]

Originally Posted by ausnp84

Ah ok, that's a bit easier then. I'm guessing you mean these two versions of the Allied Seawind?

It looks like the cutter used a longer boom and corresponding larger mainmast, but see if you can find a forum or group to confirm that.

n

Cutter



Ketch

If you look closely, you will see the mast is further back on the cutter than on the ketch (as I suggested early).

[hoppy]

Originally Posted by SKG56

I wanted to get the mast out of the cockpit, let me be clear, I don't own the boat yet, I owned an Allied Seawind 30 Cutter, but had to sell because I could not get to it, I could wait till I see a MK II Cutter I like, there is one available, but it's not near the boat that this Ketch is,

I could understand someone wanting to do such a change to a boat they have history with and have spent a lot of money improving it, but it just seems a stupid to buy the wrong boat to start with.

Look for another boat if the cutter version is too hard to find.


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[SKG56]

Originally Posted by StuM

If you look closely, you will see the mast is further back on the cutter than on the ketch (as I suggested early).

Okay, Yes, I see what you mean now, it does look further back on the Cutter, a couple of questions , say you didn't use the mizzen mast sail at all on the ketch, how would that affect the performance, and if you extended the boom on the ketch removed the mizzen mast, do you think it might cause an adverse effect, these are design and engineering problems, maybe I should just leave the Ketch like it was designed, I think so.

[SKG56]

Originally Posted by hoppy

I could understand someone wanting to do such a change to a boat they have history with and have spent a lot of money improving it, but it just seems a stupid to buy the wrong boat to start with.

Look for another boat if the cutter version is too hard to find.

Sent from my iPhone using Cruisers Sailing Forum

Yeah, pretty stupid, I am looking at other boats, I like the MK II, just didn't want a Ketch, as for the Cutter design being to hard to find, they are out there, just have to wait until the right one at the right price becomes available, this forum is a good resource for information, I like that about CF