Frequently Asked Questions

Frequently Asked Questions

Frequently Asked Questions

  1. How do I move a large trimaran with a 20 feet plus beam, especially since I am located far inland?
  2. Why are none of your  design hard chine, doesn’t it take longer to built rounded hulls?
  3. Why don’t the Amas Fold-up like most of the current poplar design?
  4. How long will it take to build this trimaran?
  5. Why build my own, instead of buying a completed boat?
  6. What about Marinas and storage for such wide beamed boats?
  7. Do your design require lofting?
  8. Can I use an outboard motor instead of a diesel?
  9. Do you provide a construction manual?

How do I move a large trimaran…?

    Hartley Trimarans are designed to be built in modular form.  You can complete the beams and hulls structures in you backyard. Most of the interior and finish work can be completed beforehand.  The modules are then moved to a coastal boatyard for final assembly. The work remaining will be bolting the beams and hulls together, installing the main cabin deck, installing the wing undersides, building the outboard cabin lockers and filleting the beam hull joints.  Most of the interior finish painting can be done and the  hulls primed.  Final painting of the exterior will have to be done in the yard. If you are lucky enough to be close to the coast, you can obtain road permits. These usually have hour and day restrictions. The first trimaran I built had to moved 35 mile to a ramp on the Savannah River. I was lucky enough to be friends with the Chief of Police, who loaned me a two-way radio with which we could communicate, while he provided an escort. He lead the way stopping traffic at all intersection and alerting me to traffic situations. We were able to make the trip in less than an hour.

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Why are none of you designs hard chine…?

    There are many reasons. But first let me dispel the myth, that flat sided hulls are quicker and easier to build. The long runs of side plywood must be scarfed and cut to fit to the chine logs. The chine log must be constructed, and strings added to the frame to support the plywood planking. All other things being equal, you have cut and setup the frames, install the keel and stem post, fiberglass and fair the hulls after planking. Let me point out that you will hate every corner on the boat, corners have to be double fiberglassed for protection and strength.  When fairing and sanding out, it will seem you are always nicking corners, which then have to be repaired. Please note that I have eliminated as many corners, in my designs as I thought possible. 
    The real reasons are engineering, beauty and value.  Round or parabolic hulls have a lower wet surface to volume ratio. They can be formed to a more hydrodynamic shape, and thus created less drag, which translate into higher speeds. The Amas (floats) can be shaped to create more lift, thus reducing the size of keel and rudder.  Wind resistance to the superstructure is also reduce, which is extremely important going to windward. (On a trimaran to windward the apparent wind can be 30 Knots.)  A boat should be beautiful above all things, a well thought out design by it’s very nature will be beautiful. Value and beauty go hand in hand, human nature ascribes value to all things beautiful.
    The time required to build hulls is something often discussed as if when you finish the hulls you are halfway home.  This is not the case, hulls construction usually requires about 1/4 to 1/3 of you time.  The time consuming parts consist of,  the interior, finishing out, installing hardware, electrical and electronic installation, motor and accommodation.  There are many fiddled pieces required for the interior, all have to be cut coated with epoxy and sanded.

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Why don’t the Amas Fold-up… ?

    All my designs are meant for extended bluewater cruising. They are for sailors, who want to live on the sea not in a marina. Check the slip prices of most marinas, they are close to a mortgage on a condo, it would be cheaper to buy the condo with a view of the marina.  It is my opinion folding umbrellas suit their purpose fine, but once in a while they do fold the wrong way when hit by a gust of wind (This in no way meant to deride any folding designs, for none to my knowledge have folded at sea or malfunctioned, which is indicative of good design or luck)
     Let me give a brief explanation of the real problems facing design and construction of trimaran beams. Righting moment must equal  healing moment on all points of sail, going to windward being the most extreme situation. The analogy being similar to a see-saw in balance. The see-saw board (Beam Truss) must be strong enough to support the weight on both ends. You can determine with equations the size requirement for the board( Beam Truss).  The problem like most on first analysis is not that simple, if it were we would only need one beam.  The main problem is racking forces, this is a twisting force generated by wave action on the Amas (Floats). The structure between the beams must be strong enough to resist this force. With folding beams all this force is concentrated and transmitted through the mainhull. The trimaran mainhull, which by it’s nature must be narrow, becomes a torsion bar and must be extremely strong to resist these forces. It would be hard to image, even in the best engineered design, that some warping doesn’t occur.  On viewing photos of formula 40 designs under sail, this is very evident. These torsion force over time can weaken the mainhull structure. 
    The Hartley solution to this problems is to design two beam trusses, each with 100% of the required strength to support the submerged float displacement. Then connect these beams with a wide box structure consisting of the hulls, wings and decks.   The torsion is now distributed over a wide area and  not concentrated in the mainhull. You also now have a wide solid deck for mounting sail track. I will not overstate the other obvious advantage, you can see for yourself.

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How long will it take… ?

This is similar to the question, how long is a piece of string.  I would have to know all about your situation, tools, building facility, skills, resources, and commitment.  Let me say that I do have estimated time for construction, based on averages. Most of these times are based my first building experience, and at that time I definitely was average in all the categories. To help you along the way toward fast completion, I have tried to eliminated most of the time consuming factors. To start with you need a good set of plans accurate and with as much detail as possible, you don’t need to become a designer to build the boat. Full sized patterns where possible, this is extremely helpful for building keel, rudder and skeg. (Templates for fairing can be taken off  these drawing). Next a lot of knowledge is a good thing, before you cut the first frame, read and learn the easy way. My first frame (Not one of my design) went in the scrap heap because I used a full sized pattern drawn on ordinary paper, I checked it against the table of offsets and it was 1/2 Inch in some place, so much for full sized frame patterns. From then on all used dimensions were from the table of offsets. [Note most blueprint paper is dimensionally unstable and grossly effected by humidity conditions] . Next a craftsman is as only as good as his tools, don’t scrimp here (Industrial only), buy the best and as many as you can afford, you can always sell them later, especially if of good quality. You have heard of those who built without a shelter, don’t try unless it never rains and the temperature is always above 70 Degrees F., where you live. If you start to apply a coat of epoxy and it rains or the moisture settles on the boat before it cures, you will have to scrape it off ( It will never harden).   Have you ever built anything, if the answer is no, a boat is hard place to start.   If however you are reasonably handy and have a quick grasp, and proceed at an unhurried pace (measure it twice cut it once), the unskilled boatbuilder can soon become a boatwright. The beauty of building your own boat is you don’t need all the money for completion in the beginning. You should however have enough money for completion of the boat structure. Most of the expense comes toward the end, outfitting, hardware, engines, sails, electronics, etc. Rome wasn’t built in a day and neither is a boat, by spreading the cost out over the time of construction, the bit is not quiet a severe. As to commitment, don’t start if you can’t do the time. Once started there will be agony and ecstasy, the agony of long hours of work and the ecstasy of accomplishment.  After unloading and piling up my first load of boat materials, I stood back looking and said to myself, "hiding in that pile of  lumber is a boat, all I have to do is find it".

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Why Built my own…?

    In today world of mass manufacturing, there are few things you can build cheaper.  A house and a boat are some of the few remaining. Building a boat is one of the few experience in my life of cherished value. Sitting on the boat, I see unfolding again in my minds eye, each and every part, the flaw and perfection only known to me.  This thing brought into existence through years of travail, is a part of me forever. Under sail, I  realize the peace that surpasses understanding.
    By knowing every part and having the skills acquired from building, you can repair almost anything aboard.  You have confidence in the integrity of the boat, you know her strengths.   I have never been afraid in the boat’s ability to carry me through the roughest of weather. Off the coast of the Bahamas, we were hit by a tropical wave, the wind speed increased to 60 plus knots in a matter of minutes and the seas mounted to 10 plus feet. We had  anticipated  the coming weather and had taken in all sail and gone on the motor. Going to weather in these conditions was impossible, which was the set course. Freeport was downwind, so we turned and ran for shelter. On the way the wind was so strong, that even without sail, we were surfing at 8 plus knots.
    In summary, building will of course will save you money. The more important factors are that you have acquired new skills and you know your vessel. You have confidence in your ability to effect repairs any place in the world.

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What about Marinas and storage… ?

        Marinas are generally out of the question, unless you can find an along side berth. Marinas have a minimum charge for slip size and in the case of  trimarans boat length is usually not the issue. The best solution is to find a mooring, or some friendly waterfront owner who will allow you to put in your own. This need not be in deep water, it could even be in a tidal zone. Hopefully the mooring location will have some protection from bad weather and there must be room for you to sail up on the mooring, just in case the motor has failed.  Be fore-warned, if you try to leave the boat on the hook, trimarans will sail-up on their rode in strong wind, which could dislodge the anchor. This can be prevented by putting the tiller over to one side and tying it off.  This will cause the boat to fetch-up.

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Do your designs require lofting… ?

       All my designs are supplied with the half-breaths tables of offset, for all surfaces. Stations per say are not used, as is the typical architectural layout for boat design. Instead sections per foot (SPERF) are used, there can be as many as 12 or as few as 2 SPERF, depending on the size(LOA) of the design.   Generally for print-outs 4/2 SPERF are used, mainly to limit the size of the design manual. (Note. The design program allows for the maximum number of SPERF to be printed out, that is if the design SPERF was 8 then 8/4/2/1 SPERF could be print in the table of offsets).  These accurate dimensional tables, are printed out in (feet-inches-sixths-plus a 32nd).
      Lofting for the entire designs is not required, but can be of value if this is your first boat.  It is however recommended that stem and transom areas be lofted.  For lofting use cheap sheets of 3/16 paneling, jointed to form a continuous surface. Number each panel, draw reference line on the Lines DWG to represent the numbered panel locations. These numbered panels can then be dismantled and referred to as needed.
     Lofting was used in the old day when ship half model were built and the lines taken off the half model. Due to the scaling errors lofting was required to determine accurate lines drawings, this is not the case for modern computer generated designs, because there is no scaling error.

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Can I use an outboard motor instead of a diesel...?

    My question to you is why would you want to.  Yes you could put a well in the lazerette for the outboard, it would have to be an extended shaft with electric start. Hopefully it will be a four-cycle like the Honda so you don’t have premix to fool with.  You could save some money on the purchase of the motor and you could take it for repairs.  The skeg would have to be shorten for the well to fit.  Now to the negative factors, gasoline is very dangerous, outboard are not as reliable as diesel, they are effected more by moisture.  Gasoline is corrosive as well, it will eat up an aluminum tank over time.  Overall a motor is there to save you and your boat in an emergency, I had an outboard on my first boat, it never started when I really needed it,  once I had to sail into a crowded harbor and round-up to drop anchor.  Then the stupid thing started after we were on the hook.  Tip: Learn how to sail up on a mooring or anchor site, practice this when it doesn’t count, for the times it will.

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Do you provide a construction manual?

    Yes, contained in the manual are the table of offset for all surface, the material list for each element of construction and related engineering data. I do not provide a step by step tutorial for building, but the manual is laid out in sequence of completion. For building instructions or a how-to, there are many good books on strip planks and cold molded construction, of which I have listed a few in  Wet Links.  All my plans are very detailed and noted with information.  But it is impossible to provide all the wood working knowledge required for construction in only the plans.  You must dig this information out by reading as many books as possible.  The best technique is to break the project down into simple steps or elements of completion and concentrate on these solely until completed. Don’t become confused and frustrated by trying to conceptualize the entire completed boat, as you build the visualization will unfold in you mind.  On the construction drawings are references to related drawings that must be referenced to for   planning the next step, e.g. if you are building the amas you need to know how they tie into the beams and deck structure. So you must think ahead only to the next related elements.  For anything complex the technique is a divide and conquer approach, the division must be on a level that you can grasp.

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Last modified: May 10, 1999