Relocating Lower Shrouds

[Red Horse]

Hi all,
The aft lowers on my Cross 38 interfere with the main when it is eased,making it impossible to get any shape to the main. I have been thinking of relocating the aft lowers to the amas. Would it be necessary to also relocate the fwd lowers. If I were to leave the aft lowers at the cabin to and move them fwd it would much alleviate the problem, but then the aft lowers would be almost in line with the mast. Any input is appreciated.
Thanks
sarge

[Tropic Cat]

I'm having trouble envisioning the issue. I think you're saying that on a run you're concerned about sail chafing on the lowers? How big a belly is apparent in your main sail?

I'm wondering if your Ama to hull attachment points can handle up to several hundred pounds of force which might be realistically induced by a main sail in a fair wind, depending on your mast height?

You would require access to the boat engineering specs to answer this question, but my gut feeling is that you'd warp the boat.

It sounds as if it's time for a new main sail or to have the current sail recut or to understand that multis are less than happy DDW and gybing tactics serve us well.

[Red Horse]

Thanks for the reply, This is not a DDW situation. It is a reaching problem as soon as I ease the main it is up against the aft lower. I will see if I can post a photo of the lower in question. The sail is cut full way too full in my opinion although a sail maker said not to worry about it. The amas have been reinforced Per a spec by Morelli for the aft stays, this is a ketch, but not for the lowers. Something I would have to do. along with some reinforcement of the beams in the amas. Not a big issue. At present the after tangs go thru the cabin top down to the main hull. Another problem is the constant leaks thru the cabin top as the tang works. There is no reinforcing in that area.
Sarge

[SailFastTri]

I think you need to engage a competent marine architect to get this right. Unless you're willing to spend big bucks, live with it and have your sailmaker add anti-chafe materials to the sail.

An alternative to moving the lowers is entirely re-engineering your mast with jumpers to keep it aligned in-column, eliminating the lowers altogether.

In either case, it will cost many times more than having your main re-cut and/or adding Kevlar chafe patches (and/or Velcro chafe strips over the battens).

[SailFastTri]

Thinking about this further -- you should contact John Marples Marples marine Services

I used his services a few years ago to survey a tri and he was very considerate and reasonable to work with. His prices were right in line with other less-qualified surveyors.

Certainly he is competent and knowledgeable: 1) very experienced multihull marine architect 2) engineering degree and accredited marine surveyor, etc. 3) has all the qualifications to back you in event your insurance company questions the mods.

[Red Horse]

Thanks for the suggestion. I should have thought about John. I built one of his boats, a constant camber 35. I sure miss that boat. It had the rotating rig on it.
The kevlar chaff strips may be a quick interim solution. Another problem is as the main is eased the battans bend around the lower. sail shape is very distorted when reaching.
sarge

[Maren]

Originally Posted by Red Horse

Thanks for the suggestion. I should have thought about John. I built one of his boats, a constant camber 35. I sure miss that boat. It had the rotating rig on it.

That isn't the one they used to make Cloudia is it? I know it had a rotating mast before they put a pair of flettner motors on it.

[Red Horse]

I don't know what hull number Cloudia was mine was 15 I believe. and John said it was the last one built at that time this was in 2004. My Marples was also named Sunbow.
sarge

[Maren]

Originally Posted by Red Horse

I don't know what hull number Cloudia was mine was 15 I believe. and John said it was the last one built at that time this was in 2004. My Marples was also named Sunbow.
sarge

Well, since we're on a roll...

What happened to you Searunner? Did you ever get it documented?

and tell me bit about the rotating mast, if you don't mind.

[Red Horse]

Sorry but I did not have a Searunner, I built a Constant Camber 35. The Constant Camber boats are designs by John Marples. Very sweet lines and nice sailing vessels at least mine was. John was not happy about my choice of the rotating rig as in his opinion they are not suited to cruising. Which may be true as the new owner dropped the rig going up the west coast to Washington. Although he did tell John he had too much sail up in too much wind. He also mentioned he was driving the boat hard to get home.
Continuing on with the lower relocation, I will fwd any of Johns suggestions in that regard, to the topic. I am of the opinion the hulls and beams can with stand any additional loads. The beams are quite heavy and with a glass reinforcing to the attachment points It appears they could withstand the loading from the lowers. Of course the amas would need doublers installed to take the loads from the lowers. The fwd lower is attached directly to the fwd beam. The aft lowers go thru the cabin roof as mentioned and put a transverse load on the cabin top. They are unsupported from the cabin roof to the attaching points in the main hull a distance of about three feet. Something along the lines of the Horstman tris'.


sarge

[Jmolan]

Redd Horse, it is a small world indeed when you get down to Trimarans in service. This is the boat you speak of. These shots are at the Port Townsend Wooden Boat Festival this year. I talked with the owner for quite some time. I liked the boat. And your right, he lost his rig going north off San Simieon.

Marples 35 is the boat John told me if he was going to do the S. Pacific again, (he has done it twice in a 37' Searunner) this 35' would be his choice. And the 34 Searunner was the same design idea. Two people for extentended cruising.

[Red Horse]

Yep thats my boat, The dodger is foam core and balsa, glass and carbon. rudder carbon fiber and balsa. Same with the center board. The interior was not finished. I was still having teething issues when I had to sell. I sure do miss that boat. The Cross is ok and can carry a heavier pay load but is not as much fun to sail.

sarge