From Schooner to Sloop?

[Skaal]

Hi everyone.
So this is my frist post here so please be gentle, if it's posted in the wrong place or if I ask some stupid questions.
I'v been looking for the "perfect" boat for a while, and we found a 48' aluminum boat that we are very much interested in. However we are not sure how perfect it is.
The thing is. The boat have been changed from the original as schooner to a sloop.
The boat is on the hard, and in need of some serious love, so there is no chance for taking it out for a test sail.
But how important is the placement of a mast?
When I asked the owner if there have been a NA involved in the calculation of the new mast placement, I got this answer:
When we converted the boat to a sloop the easiest was to weld the chain
plates to a rib (we had 2 position options 80 cm apart)... At that time our
neighbour in the shipyard turned out to be the brother in law of Dudley dix
and he offered us to forward him our plans. Dudley'reply was that both
would work so we ended up choosing the aft position for a bigger fore
triangle.
So here is my questions.
Can it be true that there is no difference if the mast is 80 cm more forward or aft?
I mean your moving the CE main aft or forward!
Headsails still have to be designed and ordered. Can the sailmaker design the jibs so the CE total of the boat is perfect, by calculating where the CE main is?
As we can't take it for a sail to feel it and test for weatherhelm, I'm a bit scared (and un experienced) to go sign the papers. So if you have the answer, please help.
Here is the boat info.
48 feel French build Aluminum.
12000 kilos
Ballast 5000 kilo lead.
Draught 2.25 meters.
Mast height is 20.2 meters above the water line.
Boom length is a bit above 6 meters.

Wow. Long post. Sorry.
Should I run, or could it still sail ok with the correct designed jibs?
Thanks
Lennie.

[Orion Jim]

I've met Dudley Dix on two occasions. He's very friendly and helpful. I'd check with him to be certain he has reviewed the plans and in his professional opinion the rig is safe and will perform well. Then I would hire a surveyor to be certain the modifications (and the general build) were done to a professional standard.

[gjordan]

Is there any way to contact the original designer or yard that built the boat? That would be much better than the word of the person (or agent) trying to sell you the boat. You are wise to be nervous. Depending on your physical stamina and experience a 48 foot sloop can be a real handfull to sail. There are also many threads on this forum, about the good, the bad and the ugly aspects of owning an aluminum boat. Keep us posted about how well this goes. _____Grant.

[Skaal]

Originally Posted by Orion Jim

I've met Dudley Dix on two occasions. He's very friendly and helpful. I'd check with him to be certain he has reviewed the plans and in his professional opinion the rig is safe and will perform well. Then I would hire a surveyor to be certain the modifications (and the general build) were done to a professional standard.

Thank you.
The boat was converted in 2012, so I doubt he remember it. The whole constitution bit of it sounds pretty solid. It's the location I'm worried about.

[Skaal]

Originally Posted by gjordan

Is there any way to contact the original designer or yard that built the boat? That would be much better than the word of the person (or agent) trying to sell you the boat. You are wise to be nervous. Depending on your physical stamina and experience a 48 foot sloop can be a real handfull to sail. There are also many threads on this forum, about the good, the bad and the ugly aspects of owning an aluminum boat. Keep us posted about how well this goes. _____Grant.

Hi grant.
The designer is as far as I know no longer around. The yard didn't do the conversion. The owner did. So not much help to get anywhere.
The only right thing to do would be to have a NA look at it. They just don't come cheap :-(

[Cheechako]

So... 80 cm is like 36+ inches or so. So 3 ft. Quite a bit for a 48 ft boat. But one must remember that location of the mast, "CE/lead" etc are a "snapshot in time".
What I mean by that is ....it changes with each sail change or reef etc. It could be inconsequential. It also could have been done because the boat had too much lee helm or etc to start with. One off boats often dont come out as designed.... especially when it comes to helm issues. I once visited the office of a well known sailboat designer for a review of my planned rig and we talked about his notes he had on boats he had designed. On one boat, his notes to himself were something like "Terrible helm! Worst I've done!"
Sail choice could make a big difference for sure. Do you have the layouts? you could compare how the current rig compares with the schooner rig quite easily... as far as CE are concerned.
Also, take a look at sailboatdata.com and compare rigs/ placements of similar 48 ft boats.
Remember, by moving the mast you are only moving one component of CE, and the overall balance is moving less than that move.

[nwdiver]

Convert it back to a schooner, as it was designed to be......

[gjordan]

I am a long way from being a N.A., but I believe that for a given sail area, a schooner needs less ballast than a sloop, simply because the rig is shorter, therefore less heeling force for the same amount of wind. If that wasnt taken into account in the modification, you could have a very tender boat or if it was compensated for, you might have an under-canvassed boat. By the time you are finished, you will have so much time and money in a project boat that you might as well spend the bucks on a N.A. up front and maybe save yourself a lot of grief. Years ago I considered buying a French built 48 foot aluminum (equal masted) schooner in Antigua. The hull and deck were obviously professionally built, but the inside was owner finished and funky. The wife put her foot down and we didnt buy it, but I really liked the equal masted rig. I think several yards in France would sell hull and deck boats for owner finishing. Who was the actual designer? ______Grant.

[gjordan]

Unless Dudley Dix is drifting off into never never land, I am sure he would remember something as unusual as converting a schooner into a sloop. I doubt that conversion is asked for often. Give him a try. Good Luck. _____Grant.

[Snowpetrel]

To convert a schooner to a sloop the mast is going to be in a drastically different place. Odds on that the placement is close to right. It's not rocket science, and there is pretty good sample size of similar boats to compare. In this case normally what looks right is right.

Is there going to be a bowsprit? If so this gives a lot of room to easily play with modified lengths to fine tune if need be.

Sounds like Dudley suggested a more aft location like his Shearwater designs.

[Panope]

Before:



After:



-Main mast moved to the foremast position.
-Boom and gaff lengthened.
-Sail area unchanged.
-Boat balances fine, same as before.
-Boat performs slightly better as a sloop (hard to be sure as 12 years elapsed between sailing both rigs).
-Boat is slightly more tender than before as the center of effort moved upward about 1.5 feet.
-No naval architect was involved with this redesign.

I'm very happy with the changes.

Steve

[daletournier]

Originally Posted by Panope

Before:



After:



-Main mast moved to the foremast position.
-Boom and gaff lengthened.
-Sail area unchanged.
-Boat balances fine, same as before.
-Boat performs slightly better as a sloop (hard to be sure as 12 years elapsed between sailing both rigs).
-Boat is slightly more tender than before as the center of effort moved upward about 1.5 feet.
-No naval architect was involved with this redesign.

I'm very happy with the changes.

Steve

What was your reason for the conversion?

[Panope]

Originally Posted by daletournier

What was your reason for the conversion?

In no particular order of importance:

-To reduce weight aloft in order to offset the weight of the pilothouse addition.
-To remove the mast from the middle of the saloon.
-To reduce the number of rig components. Simplify.
-I like tinkering/experimenting.

Steve

[GordMay]

Greetings and welcome aboard the CF, Lennie.

[zeehag]

silly me . i am partial to the before pix on this one.
the redesign was well done, but the eye, mine, that is, prefers the look of the schooner and her lines.
you did an excellent job of conversion and modernization.
i musta been a sailor in a long gone era with clipper ships and ancient rigging.