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Virus Magnum 21 S

Boat test from the Multihulls World #81 (april/may 2005)

My chief editor said "whatever happens I want some wind for this test!". So I made a date for a march day when the wind and the snow were expected...and perhaps dreaded...

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Going boomless? Magnum 21 Trimaran

Discussion in ' Multihulls ' started by nacrajon , Jan 27, 2014 .

nacrajon

nacrajon Junior Member

Having just got a new boat (Virus Magnum 21) the boom is a pain and right at eye level when on the tramp. How easy is it to convert the main to boomless? The mainsheet attaches about a foot forward of the clew. I'm uncertain if a good shape could be set. Ideally I would like to be able to buy a boomlet from NACRA and get a sailmaker to attach it. Is going boomless that simple? Obviously I would have to work out a reefing system, but that has been done before.  

Richard Woods

Richard Woods Woods Designs

So instead of the boom hitting you in the face you'll now have a free flying mainsheet block that can hit you, but is probably less obvious to keep an eye on (literally). The boomless rig doesn't work well unless you are going to windward or never ease the mainsheet past the traveller There are reasons why my Strike 18 trimaran has a windscreen and a high boom. Keeps the cockpit and crew nice and dry as well as safe Richard Woods of Woods Designs www.sailingcatamarans.com  

Moggy

Moggy Senior Member

A wishbone boom may be an option.  
I don't see why boomless is not an option on a family boat. I raced boom less NACRAs in the past and they were competitive against similar cats. I have an asymmetric kite with the wind so the main would be tight anyway to support the mast. So back to sail shape, is it as easy as riveting on a boomlet?  

TeddyDiver

TeddyDiver Gollywobbler

Just IMHO but comparing to big genoas there's no reason not to have similar sheet arrangement for boomless main aswell...  
The Clissold TC10 is boomless with a radial traveler. http://www.tcdesign.co.nz/TC_Design/Sailing_Designs/Pages/TC_10.html It works for him.  

warwick

warwick Senior Member

The Ian farrier F 22 is also boomless in the production version http://www.f-boat.com/pages/News4/FM-Factory2014.html  
I have sailed boomless beach cats. I've also sailed most of the newer Farrier designs, but not the F22. They are performance boats, as is the Weta, so pretty much always sail with the apparent wind forward of the beam. I've also sailed a Virus Magnum (there is one by my office). It isn't a performance boat. Furthermore, unlike a beach cat it has a very short mainsheet track Another problem with boomless rigs is that you tend to have to have the mainsheet track aft of the clew, otherwise you cannot flatten the sail. I suspect the clew on the Magnum is aft of the track (sorry I cannot remember it was a long time ago that I sailed one) Richard Woods  

teamvmg

teamvmg Senior Member

On a boomless mainsail, the main sheet has to angle forward so that aswell as pulling the leech down, it also pulls along the foot to flatten the sail. [It sounds like yours is angling the opposite way] They are tricky sails to get right, even when specifically designed for the boat. You would also need to upgrade your mainsheet as it will be working harder.  

upchurchmr

upchurchmr Senior Member

Interesting to call the F-22 boomless. That is a really big bottom "batten" Perhaps there needs to be a new term - they could probably turn it into a salesmanship gimmick. I didn't read the whole thing to understand the "variable stiffeness" batten. The boat and web site is really impressive, wish I would win the lottery. It was somewhat amusing to see the wide cabin at the gunwale which did not appear usable due to the narrow settee opening. Possibly just an impression since I have never sailed any of the Farrier boats.  

ianfarrier

ianfarrier Junior Member

The bottom batten is just that, a batten, but with more torsional stiffness so that it can roll the mainsail. http://www.f-boat.com/Media4/F-22Photos7/ReefedandFurled.jpg But it still bends enough to allow the best possible shape to the reefed sail. Still very light, and easy on one's head if you get in the way. It is also of variable stiffness so that it can be stiffened up downwind, but so far it does not look like this will be necessary. The wide cabin at the gunwale is very usable, for storage behind setbacks, or for the old style wing berths, but which I never found very practical, and have preferred to use settee berths since the F-27 in 1984. The wide cabin also avoids that claustrophobic feel of a narrow cabin. I had tried such a cabin on the original prototype, with side decks: http://www.f-boat.com/Media4/News6/TT18prototype.jpg The idea of having a flat side deck around the cabin appealed at the time, but it was a big mistake and never did it again. Ian Farrier Farrier Marine.  
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Thanks for all the replies, it seems boom less is not as easy as I was hoping it may be. A F22 was on the top of the list, however I couldn't make the stretch financially and I thought the Magnum met my needs better than a Hunter Tramp.  

Doug Lord

A Cat on fire!(going very fast) / M2 on foils

Skip JayR

What is going with Hydrofoiler SCAT (experimental boat) ?

Is there going a local 30 ft. trimaran circuit in sweden .

outside the box

Bazooka Trimaran going back into production

redreuben

Ormas going to Hobart

Corley

Seawind Catamarans going into voluntary administration

Boomless double masted catamaran....

Jetboy

Re-cutting beach cat sail to go boomless

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