15 Responses to “Summer Sailing in a Trimaran called Gypsy Wind”

1. Dan Says:
   February 28th, 2013 at 3:26 pm

   Looks Great!

   Dan

2. ian Says:
   February 28th, 2013 at 5:08 pm

   Nice to see all that hard work paying off, and to see the concept get tested in real world conditions…even within the ranks of very dedicated cruising boats purchased or built for that purpose, it’s astonishing how many of them never quite get past the “getting ready” stage, so just going anywhere is a big deal.

   Speaking of real world conditions, this caught my attention-

   “Having the deck overhang in the bow makes these small tris so much drier, and gives you more space on the bow when anchoring…”

   This points out one big issue I have with many of the small tri designs I see, both DIY and commercial- namely that they pay little to no attention to crew movement or deck work.

   I get the reasons behind certain design decisions like centralized seating, open wing areas with no deck overhangs, etc. but my gut tells me that a lot of the designers coming up with these boats are simply not considering the realities of operating in less than perfect conditions or are hamstrung by choosing design elements that may have no bearing on the actual conditions the boat will see (like kayak cockpits designed for hunting/fishing in arctic waters with no beaches or need to go on deck).

   Anchoring is a great example- some may see it as something irrelevant to a non-cruiser, and they would be very, very wrong…regardless of any other uses, an anchor is safety gear and the ability to store and quickly and safely deploy one should be pretty high up the list of design priorities for any boat.

   When you are standing in a tub that you can move around inside putting out an anchor is a no-brainer, but how do you do this when you are seated in a form fitting cockpit and the outside edge of your boat is 8-10 feet away in nearly all directions?

   Even if you opt for a more traditional cockpit, how do you get to the bow of the main hull to drop anchor if it is so narrow and lacking in buoyancy that there’s no space for a person to stand? Sure, you can set up remotely operated tackle, but what happens when it jams up?

   What do you do when your chute or roller furling jib wraps up on the fore stay, which coincidentally never happens when there’s light winds?

   What do you do when some oblivious drunk in a Chris Craft is bearing down on you and your only options left are to fend off from the bow of one ama or bail out before you are ground into hamburger?

   Even the best designed tris face the unique issue of the edges/corners of the boat being very far away from the cockpit and this makes getting to those edges and corners when you need to more difficult even in the best conditions…making it even more difficult by not providing any means of accessing those edges/corners seems short sighted at best and potentially catastrophic.

   Same goes for simply assuming that “it will never happen”.

   That isn’t to say that all small tris need solid decks or cabins or anything like that…but I have to laugh when I see small tris being offered up as very high tech, well thought out designs that are worth every penny of the tens of thousands being asked for them, but no provision *whatsoever* is made for being able to fend off when coming alongside a dock or for taking on passengers, and you can’t quickly move outside of a tiny central area where you are a sitting duck while underway.

   If the boat is intended as a pure racing or sport sailing vehicle then that trade off may be worth whatever gain there may be, but even when racing you have to have some safety margin and that basic margin should always be priority #1 on the list and having the ability to move around like on a normal boat doesn’t necessarily mean lower overall performance.

   As Mark points out, just the deck overhang itself makes the boat drier and quite often it’s the crew that reaches its limits first when really driving a sailboat hard…in other words, something like a spray reducing deck overhang or just a solid section of trampoline that can act as a spray deflector might actually allow the crew to keep going when an allegedly slicker and sportier boat’s crew is packing it in.

3. josh Says:
   March 1st, 2013 at 3:54 am

   I love this tri! I’ve been oogling this build since it was first posted on this site. I’m a teacher/timber-framer and have been entertaining a build notion for some time now. I get a bit tired of my wet H16 (I have camped with it before but it’s a fiasco). This boat really exudes the cruising capacity I’m after. Great craftsman build! I’m awestruck! beautiful, beautiful boat.

4. Mark Gumprecht Says:
   March 2nd, 2013 at 9:31 pm

   Josh- Thanks so much for your kind comments! It’s a lot of work designing and building boats like this, definately a labor of love you might say. It much easier to cruise around when you can anchor out instead of camping on the beach, and it’s hard to find places to camp that are not private property. Once I throw the anchor out, I can go down below and relax. Most places I’ve sailed, you usually get heavy dew at night, which can a problem when camping in a tent. The inside of the boat is really cozy, with the varnished wood and big windows. Most of the modern foam and glass boats look like refrigerators inside. Wood is still the easiest material for the home builder.

5. ian Says:
   March 3rd, 2013 at 12:24 am

   I’m curious if Mark can comment more on the mast and standing rigging, or point us to any information already online about the general layout and such.

   It’s hard to tell between the quality of the compressed video and lens distortion and all, but in the sailing video the rig seems to have a noticeable degree of movement independent from the hull structure in gusts…is this actually happening or is it just an optical illusion?

   And if it is the former, is this an intentional choice intended to mitigate overloading the hull and beam structure, or just a minor shroud tension/tuning mis-adjustment or other bug that day?

   I’m just curious about any details of the rig and especially the tang and chainplate locations and shroud/spreader geometry, since we don’t see too many more or less traditional cabin tris of this size…similar but larger designs have in the past had issues with mast pumping and other unpleasantness, and a lot of it had to do with the loads involved in trying to keep things absolutely rigid, and the more rigid wing decks transferring loads to the rig rather than just bending slightly like tubes and laminated beams can.

   The mast rake suggests some desire for bendability but like I say it’s hard to tell just what’s going on in the video…and in one pic at anchor I see diamond stays and upper shrouds but no lowers…is that the case?

6. Small Tri Guy Says:
   March 3rd, 2013 at 1:12 am

   Here is a post about the mast Mark built for Gypsy Wind — http://smalltrimarans.com/blog/?p=6282

7. Mark Gumprecht Says:
   March 3rd, 2013 at 2:33 pm

   Hi Ian,
   I do think the apparent movement of the rig in the video is some kind of camera distortion, as I have never observed it while sailing. It was an old camera, and edited from a bunch of short clips. The mast is a wooden wing mast of my own design, built out of 1/8″ luan plywood and spruce, with fiberglass on the outside. It just has the main shrouds holding it up, with a wire luff in the jib, and with spreaders and diamond wires on the mast. The main shroud are 3/16″ Vectran which attach to heavy duty eyestraps which are epoxy bonded to blocking in the deck with 1/4″ ss bolts. I never can bring myself to bolt chainplates to the side of the hull, very functional, but ugly. The attachment point is about 3′ aft of the the mast step. The Vectran probably has a little more give than ss wire, but I have never noticed the leeward shrouds having an unusual amount of slack. The winds that day weren’t all that gusty. The diamond wires are 1/8″ 1×19 ss wire, and the spreaders are raked back to load the mast forward, and counteract the pull aft of the mainsail. This is the typical setup used with rotating masts. No lower shrouds are used as they would restrict the rotation of the mast. The main shrouds only have to be tight enough to give reasonable forestay tension, and the diamond wires keep the mast straight. The structure of the boat and beams is very strong and rigid, and there is no movement there. I have been very pleased with the rig under all conditions. I really love having the two roller furling jibs. The forward sail is really a genoa, not a reacher, and can be used for going to weather in light winds. It’s great to be able to select the sail size from the cockpit, and so much safer on these small boats.

8. ian Says:
   March 3rd, 2013 at 10:50 pm

   Thanks Joe and Mark for the extra details…one thing that is atypical or at least fairly uncommon in my experience on this type of rotating mast in smaller boats is that the forestay placement makes it more of a rigid masthead rig as opposed to a bendy fractional one, and requires the supporting shrouds to attach near the masthead as a result.

   Besides any rule beating benefits that may have made it a good choice on any particular boat, the bendable raked fractional rig geometry allows higher main sheet tension to provide better forestay tension when you need it going to weather, while allowing that level of tension to be relaxed a bit off the wind when you don’t which can make sail handling easier and helps prevent gear failure. The aft raked diamond stays then act like upper shrouds to support the upper mast section- they just don’t attach to the boat proper, but back to the mast so that everything can rotate.

   Many of these designs combine the forestay tang and the lower shroud tangs into one unit attached at the front of the mast that allows for rotating action without radical changes in shroud tension at the extremes. The forestay being attached below masthead height allows the upper mast section to bend fore/aft via sheet or running backstay tension without having to adjust shroud or forestay tension every time. Seen from the side, the bending action is like bending a spline against a nail, with the forestay/lower shroud tang being the unmoving nail everything bends around, and the mainsheet and boom being the force multiplying lever-

   http://www.wayfarer-international.org/WIT/race.related/SailShape.Trim.Care.Tuning/Als.Upwind.Tuning.Basics/mast.bend01.jpg

   Some larger rigs of this type use a “baby” stay to bend against (and to simply beef things up) , and do have masthead height forestays but then the forestay tension needs to be adjusted when you bend it back and forth…the fractional rig can be made pretty passive.

   It’s an interesting approach that makes good use of a stayed mast’s natural tendency to want to deform into a curve when you tension its standing rigging up and then start whipping it back and forth, by suggesting a beneficial path for the curve to take and then adjusting the engineering to deal with the deflection. The back to the mast diamond stay setup helps keep the side loads more in line with the mast itself and the strut placement similarly introduces a point around which a gentle curve to leeward can develop.

   Another reason a bendy mast (rotating or not) with diamond stays and jumpers and such taking the place of more traditional spreaders is favored by a lot of racing boats is that it keeps the shrouds pretty well inboard and allows for really sheeting in jibs…this is an advantage on tris because it can help them point better, as can he ability to really crank the mainsail flat without overloading things. It can also help off the wind by tucking the shrouds further out of the way of the boom.

   If I’m getting what you and Joe’s link tell me, it seems that you have also dealt with the bend tendency by essentially pre-loading the mast in a forward curve not unlike a strung bow, with the tips of the aft oriented struts being the finger tensioning the bow string, as it were. Then the only actual shroud connections to the boat itself run direct from masthead or thereabouts to their chainplates.

   That’s certainly a valid way of doing and I totally take you at your word that it’s working fine, but I wonder what keeps the mast from deflecting when the rig is rotated to an off the wind position and it’s sideways edge is now more of a leading edge and the diamond stays aren’t oriented to prevent a different curve from forming as the unstayed center section of mast bends toward the bow?

   Perhaps it’s simply the overall strength of the spar/wing and maybe even the diamond stays could fail and it would stay rock solid…it obviously works and like anything else there is simply no one rig that is “best” for any particular boat or condition, they are all compromises. One way of dealing with the shifting loads on rotating spars that I’ve seen is allowing the spreader/strut to pivot to a more traditional 90º orientation to the mast as the mainsheet tension eases and the load vector shifts, and many non-rotating masts allow this action for maintaining even tension at different bend angles.

   On very small boats like these the loads involved are usually not so immense that they present any grave danger that can’t be anticipated, but one thing to consider for anyone wanting to experiment is that while pre-loaded spars allow for extreme light weight with minimal rigging, being pre-loaded they tend to fail spectacularly when things go south after too much extra load is applied, and they do it with far less warning since you are already closer to the failure inducing load point to begin with.

   Bendy fractional rig masts are easy to blow out too and are not common at all on cruising boats, but at least you have something to let go of to let it get back to a minimal degree of tension, where a bow-like pre-tension is always there. The other consideration is that in the event that any mast pumping does occur- which is more likely with no direct to deck intermediate shroud connections between the mast step and mast head regardless of any pre-loading- that pumping action will be compounded when the force of the pumping aligns with the force of a pre-loaded spar trying to unload. Not impossible to deal with, but a consideration for anyone intending to really push things or be truly dependent on the rig staying up in a big blow. I’ve experienced severe mast pumping on both monohulls and multi’s with standing rigging geometry issues and it can be truly frightening since it doesn’t necessarily only happen in a major blow but still threatens to take the rig down or maybe even hole the boat with its own mast.

   I guess the main point is that not all rig motion or deflection is bad, but some varieties are very, very bad and it is important to understand why when choosing or designing rigs…

   Anyway, it’s a gorgeous boat and a gorgeous stick and you clearly got the job done and it’s very much a favorite of mine…thanks for taking the time to answer my questions.

9. ian Says:
   March 4th, 2013 at 5:18 am

   A couple of other quick questions if Mark happens to read this- is the gooseneck fitting and boom attachment scheme more or less traditional with a U-joint type action, or is it more rigid to help with the mast rotation the way some rotating mast dinghys like the Finn do it?

   Also wondering how the rotation works in various conditions i.e. does it ever hang up or need help to re-orient in light airs, or does the rig need any kind of help to prevent it over rotating the wing mast to a less than ideal angle of attack when the wind picks up?

10. Mark Gumprecht Says:
    March 4th, 2013 at 5:07 pm

    Hi Ian,

    The gooseneck is ss u-joint I made attached to a short car that slides in u shaped ss track at the bottom of the mast. There is a 4 to 1 downhaul to tension the luff as I don’t have a halyard winch. There is a rotator arm attached to the mast with a short line to an eye in the bottom of the boom to a cleat, which allows you to adjust the mast angle. Less angle going to weather, more off the wind. The mast just follows whatever the boom and sail are doing, no need to manually tack it. The mast rotates very freely on the delrin socket, and will rotate almost 90 degrees when off the wind.
    If I had your e-mail address, I would be happy to send you some pictures.

11. Small Tri Guy Says:
    March 4th, 2013 at 5:53 pm

    Mark, I will privately send you Ian’s address.

12. ian Says:
    March 5th, 2013 at 1:48 pm

    Thanks Joe and Mark for getting me the details…just in case others are interested, the classic Finn dinghy gooseneck setup I mentioned is illustrated here-

    http://classicfinn.org.uk/wp-content/uploads/2011/02/rigpage11.gif

    Note that the boom can be set to swing freely upwards for deeper mainsail draft in light airs and off the wind, but binds up in the up/down direction at 90º when sheet tension pulls it down, at which point the boom becomes a lever you can honk everything down flat with…something that becomes more and more necessary as speeds and apparent winds increase.

    That force multiplying “kicker” lever system in the drawing allows that trim to be held independently of the main sheet-

    “Initially Finns had no kicker, then it was found that a wedge in the boom slot held the boom down better and shortly after an adjustable wedge was devised, followed by a drum kicker winch which was common until the 70s. Nowadays custom levers are used but a drum or kicker lever (pointing upwards not down) are equally effective if rigged well. Elvstrom realised the importance in the 40s of sheeting the boom outboard so almost all Finns have adjustable travellers. These requirements do not change between rigs so setting a newer rig on an older boat is not a real problem.”

    http://classicfinn.org.uk/?page_id=27

    Otherwise the Finn gooseneck has no side to side rotational axis and the entire mast and boom rotate as one unit in response to wind and control forces…combined with the rig’s bending/flattening ability, maintaining a boom down, flat leech trim is possible even when running and reaching-

    http://www.yachtsandyachting.com/photos/finn/yandy80937.jpg

    http://farm3.static.flickr.com/2456/3605212548_333f213f17.jpg

    It’s an interesting method of making the mast rotation and positioning as hands off as possible, and could still be used even with non-bending rotating rigs where the boom can swing freely up and down.

    Also, here’s a bit on the issue of handling the changing load vectors on the Finn’s unstayed rotating mast as it reorients in off the wind conditions-

    “In order to provide sufficient strength for running, the sideways stiffness must be approximately double the fore and aft stiffness. All Needlespar masts have this characteristic although some models achieve the relationship by shape (i.e. oval) and others by increase of wall thickness. The maximum wind force that can be captured by helmsman is clearly controlled by his weight and the stability of the boat, but when going to windward most helmsmen have to let the sail out or pinch a little higher into the wind when overpowered. Downwind with the helmsman sitting well aft to prevent the bow submerging there is roughly double the stability and control can be maintained again until overpowered by lack of weight.

    The mast must be strong enough at deck level to resist a bending moment fore and aft when beating to windward and a larger bending moment downwind which is taken by the sideways shape of the spar as the rig is turned through 90 degrees for the running conditions. At deck level the shape needs to be twice as strong sideways as fore and aft, whilst at mid height the stiffness is equal and the mast can be circular. Towards the top the masts needs to be stiffer fore and aft than sideways.

    If the engineering is correct a non technical sailor (and they are generally the fastest ones!) will look at the mast whilst racing and say it bends in a nice curve, This ‘nice curve’ has a constant radius – it is part of a circle and it means that the sailmaker can plan for a regular luff curve. It is a happy coincidence that the ideal engineering mast happens to bend with constant radius of curvature which is also ideal for sail control. It must be remembered that the chord of the sail varies from zero at the top to a maximum at the boom and this means that as the mast bends the sail fullness is progressively flattened from the top down towards the boom. It is therefore possible for a mast that bends in a constant radius of curvature to have one sail that works well in a wide range of wind speeds.

    The Finn rig looks simple and elegant but is in fact a much more sophisticated aerodynamic arrangement than the conventional classes that have a mass of wires holding and controlling the mast.”

    http://classicfinn.org.uk/?page_id=116

    Even though it’s a smaller unstayed rig, there’s a lot to be learned from the Finn and I think much of it could be particularly suitable for trimarans, where sail performance is a major limiting factor in overall speed potential.

13. Mark Gumprecht Says:
    March 5th, 2013 at 4:42 pm

    Hi Ian,

    I’m not sure why you go off on all these tangents that have nothing to do with the original post or information I sent you? One of the things I love about tris is with all that beam, you can have a real preventer and downhaul led out to the ama that allows you to do anything you want with sail shape and make it impossible to gybe the main.

14. Small Tri Guy Says:
    March 5th, 2013 at 4:55 pm

    Hi Mark,
    I’ve corresponded with Ian many times over the past couple of years and I believe his intention is to simply share helpful, and sometimes even “out-of-the-box” information with other readers. There are guys who may get some ideas from what you’ve accomplished and then take that knowledge in a bit of a “different direction.” On a blog site, such as this one, it commonly happens. Social media developers refer to this as “adding to the conversation.” I always enjoy seeing what guys like Ian come up with (in the way of other thoughts) or share with others (in the way of reference links from elsewhere on the web) that may or may not relate directly to the original concepts presented in the small trimaran post.

15. ian Says:
    March 5th, 2013 at 6:26 pm

    Joe is 100% correct that my intention is to simply add to the information available which in the case of small trimarans is pretty slim in the context of sailboats in general.

    I’m not here to make a name for myself or establish myself as any kind authority who isn’t to be questioned; people are free to research anything I might say and correct me if I’m factually wrong…I have many decades of experience sailing/cruising and rigging/building boats of all kinds including square riggers but I’m also not here to get ranked on some scale of whose experience makes their commentary more worthy of attention and if people want to dismiss what I say out of hand because they don’t like the way I say it, that’s their prerogative.

    This site has established itself as being one of the best repositories for this kind of information available, and almost any search for information about small tris will eventually lead here. That makes it a natural choice for anyone who might want to add to the general conversation and have it be worth the effort, so that (for example) someone who is interested in rotating masts who ends up on this thread gets more to chew on than just a single example.

    The other thing I like about Joe’s site is that he seems genuinely interested in the entirety of what is out there whether it be something directly related to small tris or is just something that might find some application in that realm or be worth knowing for a small tri enthusiast…he doesn’t discriminate between power or sail, or racers or cruisers, or DIY vs. commercially built boats, or even small vs. large or even monohull vs. tri if it’s potentially useful to small tri enthusiasts.

    In that same sense he clearly understands that what might seem tangential or off topic at first glance could be very enlightening to those who can approach it with an open mind and are willing to look outside the box, who might have very different design or operational considerations than those that led to the final form or rigging of any particular boat being discussed.

    In other words, no design is perfect as is for every person who might be a potential user, and every choice that a designer, builder and/or rigger makes has pros and cons that come with it that are worth knowing about if you want to make the best choice.

    Frankly, I’m not sure why someone would get the least bit bent out of shape over someone simply acknowledging this (unless their contention is that their boat is in fact perfect as is and there is no room for improvement or alteration that might make it more appealing to another owner or for differing applications), and to be fair I *did* qualify the post about the Finn’s rotating mast arrangement as being posted “just in case others are interested” in something that seems perfectly germane to a discussion about operating boats with rotating masts. Clearly you weren’t.

    I’m actually a potential builder/customer for exactly this kind of boat, and so it’s doubly puzzling to get this kind of push back from someone ostensibly interested in having his designs embraced by potential builders/customers, for just asking questions and simply wondering aloud about alternatives to a single aspect of the overall design- a design that I’ve said more than once I really like.

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