Norman Cross Trimaran

[bertbeck]

Jeff Turner seems to have disappeared. I have a Cross 36' Ketch and plans for it - if there's something you'd like me to check I can take a look.

Bert

[bertbeck]

I'm rebuilding and extending a 36' Cross - adding an extra 4' and re-doing the hulls (adding 3' to the floats). I have 1/2" plywood that had 1 layer of glass. I am thinking about significantly beefing this up and am looking for opinions (or better yet experience) on this. It's old - 1964 - plywood and fasteners are so so. Not bad - but I imagine 1/2 the strength or less that when new.

I am considering these options:

1. adding 1 layer of 10oz glass 1, plus 1 layer 3/8" cedar on 45 degrees, plus 1 layer 1/4" ockoume marine ply at 45 degrees + 2 4oz layers of Dynel for sheathing and toughness. The cedar to give me some extra displacement at low weight, the plywood for strength - making a plywood sandwich with the cedar in the middle.

2. adding 1 layer 3/8" cedar on 45 degrees (no glass underneath), plus 1 layer 1/4" okoume marine ply at 45 degrees + 2 4oz layers of Dynel.

3. 1 layer 1/4" okoume marine ply at 45 degrees + 2 4oz layers of Dynel.

4. 1 layer of 10oz cloth, 3/8" corecell foam, 1/4" okoume marine ply,
2 layers Dynel

5. 1 layer of 10oz cloth, 3/8" corecell foam, 2 layers Dynel

6. Just 2 layers of 20oz biaxal cloth.

I am strengthening all areas of the boat and lengthening the cockpit and read cabin. Goal is to have a more comfortable boat, and one that survive significant impact - will be gunkholing and exploring. It will be in the water most of the time - before it was a 4 month per year canadian boat - I think that's why the ply survived so long.

I'm very interested in the tradeoffs and approaches to making a hull stronger. I see the weight as the downside, that's why I like adding cedar or corecell. I like the added insulation value as well and a little more bouyancy to compensate for the other changes I'm making. I have also removed the long keel and will replace with a much shorter one, daggers or leeboards - haven't decided yet.

All comments appreciated - I'm using this project as a learning experience for more boat building -

Bert

[Pat Ross]

I am looking for a set of Cross Trimaran plans for the 48B Plan or larger in Airex.

Please contact me if you have a suggestion. I have been unable to contact Jeff as well. Hope all is well with him.

Pat Ross

pat@multihulldynamics.com

[Paul B]

Originally Posted by Pat Ross

I am looking for a set of Cross Trimaran plans for the 48B Plan or larger in Airex.

Please contact me if you have a suggestion. I have been unable to contact Jeff as well. Hope all is well with him.

Pat Ross

pat@multihulldynamics.com

I just ran across Jeff at the club. He was rigging his boat.

He had an identity theft problem at the end of last year, then moved house. So he is still a couple of weeks away from having access to his e-mail accounts and his website.

Check back with his Cross website in 2 or 3 weeks and hopefully he will be back in control.

[Lucianowestphal]

Hy i have a 38 Norman Cross here in BRasil , i have the plans too. If you want the plans of these 38 we can see how send it to you.

[Lucianowestphal]

My name is Luciano, and I'm from Brazil. I own a Norman Cross 38 1972 for more than 15 years.

In the past the boat was 2 rigs ( Ketch ). However, the wooden rigs were rotten, and I switched the 2 rigs to one bigger aluminium rig that is in the same place of the older front rig. I removed the back rig out and installed a bigger rig in the same place of the older.
Now I"m refurbishing the boat and i just whant to know if the rig position can be the same as before. Do I have to replace the rig forward or backward for better performance ?

Before the front rig was 12 meters( 36 feet ) and back rig 8 meters (24 feet ).
Now I only have the front aluminium rig 15,5 meter ( 46 feet ).

[johnholland4]

Nice to see all the enthusiasm for Norm Cross designs. I just bought a 30' earlier this year and was struck immediately by the sweet lines that the cold-molded cedar allowed, the simple, roomy interior. Boat needed a lot of tlc. I have about another month when I return to Florida in November, then hope to load up the kayaks and head for the Rio Dulce. Did we get any confirmation that Jeff Turner is still with us?

[ThomD]

Bert,

I sail out of Grand Lake part of the year.


"I'm rebuilding and extending a 36' Cross - adding an extra 4' and re-doing the hulls (adding 3' to the floats). I have 1/2" plywood that had 1 layer of glass. I am thinking about significantly beefing this up and am looking for opinions (or better yet experience) on this. It's old - 1964 - plywood and fasteners are so so. Not bad - but I imagine 1/2 the strength or less that when new.

What exactly is wrong, wood will last relatively indefinetly unless it gets wet. If it gets wet and/or rots, either one will compromise the wood and will not be amenable to any of the options you mention.

1/2" ply in a 36' boat is massive to my way of thinking. So I would be loath to add extra weight. The fact the displacement will be increased is less of a consolation on a multi than a lead mine, since extra weight in the wrong part of the multi can be rough on the structure or adversly affect the distribution of bouyancy.

Without knowing more about the boat it is hard to know how you should proceed. I woudl generally be loath to change the whole scantling of the boat. If it were mine, I would want to know what the real issues are and undertake restoration to original or improved scantling (lighter for the same strength). All of this would be a better education in boat building for you than beefing a design up. Tri are like aircraft, extra weight is not good design.

[johnholland4]

Here's another Norm Cross question (though obviously not specific to Cross tris). Has anyone had experience with self-steering mechanisms. I'm looking to buy one. Any advice? I have a Norm Cross 30' tri with tiller steering and an outboard rudder, with outboard motor on the port side of transom. Am looking at a Cape Horn self-steering right now. Anyone???? Also interested in used if they're around. John

[jmolan]

I have had two Auto-Helm's, One I built as a copy, and another one that came with this boat. Outboard rudder 34' Trimaran. It is really the best way to go ifyou have a tri and outboard rudder. What I mean is, trim tab, and wind vane.
Should be a few pics of it in the URL below. They are not cheap by a long shot, but then again, it was not that hard to build. After building one in Aluminum I figured the next one would be Sced. 80 PVC......if you look at it, it is real simple

http://tinyurl.com/mml2sc
http://tinyurl.com/m7orsv

[johnholland4]

J - Thanks for that. I looked at both your sites but couldn't make out much on the sterns. Any plans or views of that home-built system? Searunner and beemer! You're in my universe buddy. John.

[jmolan]

Sorry for my slow reply. I had to dig these shots up and re-size them. I do not have any shots of the home made unit, it was before digital photo's. It looked exactly like this unit though. I had it anodized and everything. It worked really well. So does this unit.
Basically all you need to do is transfer the horizontal movement of the the vane through a set of ss bike cables to a trim tab mounted behind the rudder. It works really well. You adjust course by adjusting the base of the vane. Whichever way the front of the base is pointing you will be steering.
The secret to good self steering is to have a boat that steers well. A boat that is light on the helm, will be light on the vane set up.

[johnholland4]

That does look pretty neat. I'll try it. Thanks for the pics and advice. John. (Toronto).

[Wally]

Originally Posted by Paul B

I just ran across Jeff at the club. He was rigging his boat.

He had an identity theft problem at the end of last year, then moved house. So he is still a couple of weeks away from having access to his e-mail accounts and his website.

Check back with his Cross website in 2 or 3 weeks and hopefully he will be back in control.

Hi Paul B
I'm looking for Jeff as he is supposed to be sending me study plans for the Cross 18 & I've been unable to get a reply using his e-mail address. Please can u let me know what's happened to him.
ta
Wally

[kelldog]

Hello;
Any word on Jeff Turner? I still need to get in touch with him regarding my Cross 28.
Thank you.
Kelly
Cross 28/30
S/V Mystic