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paulcapron 08-30-2010 04:14 PM

swept back spreaders without backstays
 
I am interested in any information or opinions on swept back spreader angles for masts without any backstays (standing or sliding) to accommodate big roach mainsails. Several new boats with no backstays are: (1) the new Beneteau First 30 with a reported spreader angle of 25 deg.; (2), the new Alerion 33 looks like it has about 25 deg. spreaders from drawings/pictures; (3) the new e33 is reported by Sailing to have 30 deg. spreaders. These boats have carbon fiber masts which also helps.

The boat I have is a Telstar 28 trimaran with a big roach main with full length battens that hangs up on a fixed backstay (absolutely terrible in light air, and extremely annoying in heavier air requiring mainsheet loosening/tightening on every tack). A very knowledgeable offshore sailor, with quite a bit of trimaran experience as well, thinks that the 20 deg. swept back spreaders on the Telstar 28 will be fine without using the backstay. An advantage of the Telstar is that in addition to a very robust aluminum mast, it also has two permanent A-frames (going fore and aft for single-handed mast lowering), that also provides strong support for the lower part of the mast up to about 8' off the deck. This is somewhat similar to the Hunter sailboats that all have B&R rigs with no backstay (they have 30 degree swept back spreaders and similar, but less robust, lower mast fixed support struts).

Any opinions on, or experience with, swept back spreaders without backstays would be appreciated.

jackdale 08-30-2010 04:49 PM

A better solution might be a backstay whip, that will lift the backstay allowing the roach to clear. It may mean using high modulus rope for the backstay.

Faster 08-30-2010 05:15 PM

Quote:

Originally Posted by jackdale (Post 638445)
A better solution might be a backstay whip, that will lift the backstay allowing the roach to clear. It may mean using high modulus rope for the backstay.

That's exactly what we did on our 3/4 fractional rig with single swept spreaders.. it works quite well except the Dyneema tends to set up a fairly loud whine when tensioned in a breeze.

paulcapron 08-30-2010 06:23 PM

whip solution
 
I did try this. It didn't work because metal backstay was too heavy, and I realized I would have to change to non-metal backstay. It is a backup, but I would rather not have to fool with that at all if possible. Thanks for inputs.

knuterikt 09-01-2010 01:09 PM

Replacing the wire backstay with a dyneema w/whip must be less work than..
1)alter/replace the spreaders
2)mount new chainplates for the shrouds
3)make new shrouds

paulcapron 09-02-2010 09:44 AM

Clarification
 
Clarification to the post implying I need new spreaders/chainplates: my Telstar 28 trimaran already has 20 degree swept back spreaders and very robust chainplates that also support a permanent A-frame that supports the mast during raising and lowering. The A-frame also supports the raised mast similar to B&G rig struts used by Hunter sailboats.

In about a month or so I will report on how not using the backstay at all works out in practice for Telstar 28, and if I feel I need to add a temporary lightweight backstay for some conditions (with or without a whip). In typical light to moderate airs that we sail in I have no concerns, but I can envision some conditions where this might become an obvious need (although I hope not).

k1vsk 09-02-2010 02:44 PM

if you don't typically single-hand, running backstays would solve the problem

Boatsmith 09-04-2010 10:46 AM

The whip and synthetic backstay is the choice of most. Of course with 20 degree swept spreaders you can sail most of the time just fine. But when you are running deep and you stuff a wave and the hull wants to stop and the rig doesn't or you jibe with a liitle too much gusto you stand a good chance of the rig going over the front. Raking the rig aft will better your clearance, other issues aside. You can also cut some of the roach off and clear just fine. The backstay is there to both flatten the main and to tension the headstay which will flatten the jib entry as well as make it furl better. If you don't care about these performance issues then cutting the roach should not be an issue.

bcbit01 09-24-2012 11:49 AM

Re: swept back spreaders without backstays
 
My Santana 525 has a 4/5 fractinal rig with swept spreaders (seems to be 20-22 degrees), a wire backstay at the masthead and wire/rope running backs off handers at the headstay level. I use the running backs exclusively and forget the backstay is even there except in a big blow. I've never seen any evidence that my rig has been over-stressed (and I check my chainplates, standing rigging, etc. pretty often.) I'm considering doing almost exactly what you are. I want to short the jib to a 105 on a furler and make up the sail area in a fathead full batten main with two reefs. (I also want to glass in a retractable sprit and add a masthead A-Sail but that's down the road) Now...this is not a set and forget rig. You need to be more mindful of conditions and reef earlier not later too keep her on her feet. For those that think deleting the back stay was bad enough without adding more mainsail area...I saw a system on a boat once...with dual running backs (twin masthead and twin headstay heighth runners). the mast head and lower runners are connected by an upper "loop" of wire with a pulley which is attached to a 2:1 / 6:1 tackle in the stern quarters. It is supposed to both provide maisail flattening at the masthead AND keep the forestay taut with one control line. Switching runners back and forth is more line to pull each tack but I got used to it pretty quickly. I'm not going to turn this into a 9kt surfing machine but I think the changes will cause the boat to make speed more efficiently in light to mid-range air and, with sufficient mainsail shape control, make it much more tune-able to changing conditions.


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