Trimaran - Especially Searunner - Owners

[rossad]

Originally Posted by Arthurwg

Is anyone building a new Searunner these days? I know I would like to.

Yes wouldn't that be a great project. If only we lived a longer life. Time is precious we need to sail away. Often you hear about the build is just too much for people and the dream fades away.
New Wharram Cats are still being built which amazes me. Why not build a new Searunner. They still have good enough qualities even in this time of age.
Maybe the 37SR is the one. Because you could do some small changes to the design that would really work. But the actual main design of the hulls sterns you mustn't change because it works so well in all points of sail.

[longjonsilver]

Originally Posted by thatguyrob

Sorry I should have been more clear, maybe the front 3 or 4 feet of the ama.

I chased down the rot and water intrusion plus a bit just to be sure!

Thanks.........Rob

Do you have a copy of the Searunner construction manual? Available free on the internet. Maybe that would help. John bought her from the builder. Ask John if he still has contact information for the builder. If that doesn't work, then call John Marples and ask him for the necessary drawings.

jon

[thatguyrob]

That's a lot of Jon's in one post.

The original builder used the plans as wall art, if I understand correctly they are no longer available.

Second owner never had 37 plans, so I guess I will contact Marples.

Thank you......Rob

[longjonsilver]

Originally Posted by thatguyrob

That's a lot of Jon's in one post.

Only one Jon, but two Johns


jon

[buoyracer]

must get computer literate- srry been outa touch- saw few pages back rossad mentioning link to the searunners owners page- have tried it couple times over the years to update our 34, but seems to be inactive & not accepting new info. anywhere else owners can update details? nice to see a tri has again cleaned up the coastal classic here in nz with a new record over the tri vodaphone that held it previous. course that only 'cos i not racing this yr. ha. oh, hi all

[trimarannaga]

Jim Brown describes in pretty good detail how to build a self steering wind vane for the searunner.
I have a searunner 40, i have the construction manual with the wind vane instructions, but my rudder is very stiff and i find it impossible to believe that a 4" trim tab is going to move the rudder enough.
I have a quadrant with stainless cables leading to the wheel at the center cockpit. But lets look at all the turns that those steeting cables make.
1: it goes around the quadrant at around a 70° angle and to port.
2: it goes around a sheave aft at 90° and goes forward.
3: it goes thru another sheave under the cockpit at 90° and goes inboard.
4: it goes thru a final sheave under the pedestal at 90° and up.
5: The end of the cable.goes to a chain on a gear that turns the wheel, 180° around that toothed cog.
Then it goes back on the other side of the boat back to the quadrant with the same number of turns and sheaves.
I replaced my steering cable last year so i KNOW the rudder moves freely and easily without the cables attached.
So...
How can this self steering vane work without disconnecting the cables?

[Tusitala]

Hello Naga, on our SR34 there is a large clevis pin with a quick release retainer to disconnect what Jim calls the "wiggler" from the steering head inside the sterncastle right where it all comes through the transom. We ended up taking it all off the boat and using a wheel pilot. Crowded waterways around here made for some pretty limited opportunities to be able to use it. Our current steering setup is hydraulic, and I have to say it works well, though with absolutely no feel in the helm.

Pat

[buoyracer]

Someone was asking about SR’s for sale- in auckland atm- ‘raven’ a 34 & ‘oceaneer,’ a 37- both have v good stern scoop extensions. Bumped into ‘oceaneer’s’ ex owner recently, he made tracks all over pacific in her. Keen to have her back but started on a catamaran build. Yeh, disgrace. Tri on the water any day thanks, but when it comes to maintenance... & imagine only having to lift ½ the boat weight to work under a hull... & the stability on the hard...
Vanes: got sr 34 plans kicking round here somewhere [thanks to ‘boatguy’- hope jeff & family on boat somewhere hot & sunny]- no doubt jim’s vane system effective- with one in mind I changed from the morse rack sys & ran lines from a longer tiller stub than quadrant, both lines running together 1 side [why run 2 sides?] & rope, so v light response for when I got off arse & made vane. Gave dimensions in a post here while back. For previous boat had just made a direct drive vane, bellcrank & pushrod to tiller, still worked fine. As a btw anyone doing a heath robinson diy, ally mtr bike sprocket, even just pushbike pedal crank with drop down pawls for locking vane angle... happy sailing

[slowbat]

Originally Posted by trimarannaga

Jim Brown describes in pretty good detail how to build a self steering wind vane for the searunner.
I have a searunner 40, i have the construction manual with the wind vane instructions, but my rudder is very stiff and i find it impossible to believe that a 4" trim tab is going to move the rudder enough.
I have a quadrant with stainless cables leading to the wheel at the center cockpit. But lets look at all the turns that those steeting cables make.
1: it goes around the quadrant at around a 70° angle and to port.
2: it goes around a sheave aft at 90° and goes forward.
3: it goes thru another sheave under the cockpit at 90° and goes inboard.
4: it goes thru a final sheave under the pedestal at 90° and up.
5: The end of the cable.goes to a chain on a gear that turns the wheel, 180° around that toothed cog.
Then it goes back on the other side of the boat back to the quadrant with the same number of turns and sheaves.
I replaced my steering cable last year so i KNOW the rudder moves freely and easily without the cables attached.
So...
How can this self steering vane work without disconnecting the cables?

4" seems small for the 40' Searunner - I used a 4" tab for my 25' with a Scanmar unit - I got the ratio 20% from the 1967 A.Y.R.S. book about self steering units. I had bad cable leads under the bunk that caused stiff steering with the tiller. when it was stiff the trim tab caused the boat to correct the wrong way, I reversed the cables to the tab and it worked "Okay". Later I 3D printed some shims for the cheek blocks and corrected the cables. Over all I happy with the auto helm from Scanmar and they have every part available down to the washers with fantastic tech support. I still run a ST2000 tiller pilot for under power and the self tacking feature single handing

[Roy M]

I guess you didn't see the detail on the "tiller arm" disengage that Jim designed. It allows the steering cable to disengage the rudder when using the wind vane, causing the trim tab to take command of the now very flexible rudder. To re-engage manual steering, you merely spin the steering wheel to one side, re-engaging the "knife blade" in the tiller arm with the steering cable.

[rossad]

Good point Roy.
This 37 SR was the best self steering I have seen. But I don't think I got enough detail in these pics.

[longjonsilver]

Originally Posted by rossad

Good point Roy.
This 37 SR was the best self steering I have seen. But I don't think I got enough detail in these pics.

Thats a really nice looking SR37.

jon

[buoyracer]

enjoyed all the pics guys, & yep sea weaver as pretty as ive seen. scoop same as i came up with but mine still only
on paper

[slowbat]

Installing twin furlers on my cutter rig SR

I will need to convert the sails luff line from hank-on. My questions to anyone with rollers - Is it worth converting all of the sails or do you just always roll in to reef? My storm sail also has a beefy wire in the luff to two eyes (head & foot) Any thoughts of running a second inner stay to keep this thing bullet proof or just convert it too?

Thanks

[Tusitala]

How far you can reef your headsail depends on how large a sail you're starting off with and what material it's built out of. The genoa on our SR34 is 110% and is made of Hydranet, so we can furl it to almost nothing without stretching it completely out of shape, and since it only has moderate overlap to start it's not a huge roll of material on the stay at leading edge of the sail killing upwind performance.

You could likely get by with a furler for just the headstay and leave the staysail and stormsail as hank on, lighter, simpler and less cash. If you do convert the staysail to furling I imagine it would be simplest to get the stormsail changed over to fit rather than dealing with additional rigging.

Pat