Trailerable Multihulls

Discussion in 'Multihulls' started by JCD, Mar 4, 2008.

  1. Richard Atkin
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    Richard Atkin atn_atkin@hotmail.com

    Excellent post Phil, but you left out one major factor....MONEY :D

    J's design proposal would undoubtedly be a compromise, but I think that is the name of the game in this case.
     
  2. JCD
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    JCD Follow the Bubbles!

    Hello Richard,

    You did a good job. You're welcome.

    No...keep it in. Bottled water is always good anyway.

    Ahem...:eek:
    Well, I went back and checked the source and the damn thing was written in "imperial" units and then at the very bottom of the page...a little note saying it needs to be converted to metric. I guess it was too difficult to write the damn thing in metric to begin with. There were conversion omissions...the big differences were in the formulas that required conversion. I am attaching the sheet for you again. I am sooooo glad that Richard, the other Richard caught it.

    It will perform well.
    "Speed Knots" is the speed the design is expected to produce based on the velocity ratio which takes displacement, lwl, SA into account.

    "Stability Speed" to lift the hull is the speed in knots when the design is at max RM so, raising the hull any higher reduces RM until everyone goes swimming.

    Reef speed is speed in knots when you should put a reef in the sails, it is arbitrary...the higher the percentage, the closer it gets to stability speed which may be good for racing but not for cruising where a gust can catch you off guard and well...swimming

    Base speed is the hull speed based on the Lwl and also takes SA and displacement into account. I was working with long tons = 2240#. The texel number does not look too low anymore and as Richard already pointed out, they were way off. I hope I calculated it wrong again. I would like to see what mine compares to. Probably a damn tank.:mad:

    It sounds right...I want it so that it can be utilized by her skipper on land and in the water...not just in the water and then transport it without being able to use it on land. Hmmm...recognition is not that important as long as someone doesn't steal the idea and call it their own, besides...it has yet to be proven that another trailerable catamaran does not carry the rating. Conversely, it hasn't been proven that there is any rated either.

    Big challenge is an understatement. I also believe it can be done if I can just get it straight in my head and then on paper. Richard did point out quite a few more boats that are capable of crossing and have done so, but it is still to be established that they are rated for offshore use. I guess that will be up to me.

    There is a definite possibility that a design out there is rated, but I'm beginning to think from all the reasons that have been offered as to why my design wouldn't work that it has not been done for belief in those reasons eg., Not enough LOA, not enough accommodation, not enough load capacity, not enough comfort, too heavy, etc, etc. I suspect those may be enough reasons to cause any designer to focus on other "food" producing designs. Ergo..."a designed offshore Category B rated trailerable catamaran" does not exist.

    I’m attaching the re-calculated results for both the 26’ and the 27’ just because I don’t want to leave any data that isn’t accurate out there…but I will fine tuning and streamlining the 27’

    Thanks
    J:cool:
     

    Attached Files:

  3. JCD
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    JCD Follow the Bubbles!


    Hello Richard...

    Great idea. I think Mr. Woods has it covered with flotation and gravity and a little help from a gantry.

    The problem I see is having to deploy them to full beam before utilizing them. Then comes the jacking up etc. Nah...I envision a driver tired from driving all day parking the vehicle, walking up a ladder, going in to the cabin, shower while food is cooking, eat while watching a little tv in bed and falling asleep to wake up with the coffee pot having already made coffee, attend to health and comfort, climb out and drive off.

    The sliding cuddy into the cockpit is the way to go. even if he parked early and wanted to sit out in the cockpit, he can slide out one side 4 feet and whala...instant porch.

    Thanks
    J:cool:
     
  4. JCD
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    JCD Follow the Bubbles!

    Hello Phil...welcome to the thread. I hope you stay and continue to contribute.


    Well...perhaps it will begin to look like something once I get past all the obstacles I'm facing and it becomes more linear than jumping around testing different things. I agree both designs are definitely different from each other.


    Eventually, I may need some "hands on" build advise, probably at the design stage. May I call upon you for advice? I agree that the designs you mention both do very different things as they were designed to do different things right from the design stage, as such. I believe when you say that you cannot make one boat do what the other does but that is because one was not designed to do what the other does.

    Let me ask...can a design that is rated for offshore sail inshore? Yes. Can a design that is rated for inshore sail offshore? They have and shouldn't, but the answer is yes. Now, if a trailerable catamaran can be designed right from the start to be: 1., trailerable, 2. offshore rated...can it be trailed and can it be sailed inshore? Yes. Lakes? Yes. Offshore? Yes. I know it is only Category B, but it is an offshore rating.


    Offshore as you mentioned, you want the least you can handle. I agree and then I also have to balance the amount of weight that can be trailed behind a car. I also believe that I will be able to get "as small as possible" a package behind a trailer. Yes, the sliding system into the cockpit may be new because I have yet to see it, but the sliding system, which is not new or my idea, would be excellent for my concept.

    I respect your opinion that it may not be possible to get both in one boat but I can't agree. Monohull trailerables can go up to 10K#'s, are trailered and are offshore rated. Yes, I know, it's a mono, but, preliminary calculations based on the actual dimensions and weights of the design demonstrate that it can be offshore rated and well within trailering limits. That is no longer difficult to prove...more difficult is all the components to make it happen. I am experiencing significant distress with this portion, but I think I will overcome it.


    Perhaps the stability has to do with weight? Perhaps the trailerable was not designed and rated for Offshore Category B. It is well documented that many designs have crossed without the rating, and 90% of that credit, IMHO, goes to wise skippers going when the weather is good.

    The difference between those designs and the design I envision, is the 10% and that difference is the Category B offshore rating that gives you 10% more chance of surviving bad weather or a foolish skipper.


    Have you looked at the design?:confused:
    For the size...the bows are very high! At the "rough" design, they stand at 5.3 feet from keel line and 4.1 feet from the waterline! I had to reduce windage up there! Reserve bouyancy? What? You can't bury the bows! Payload? More than 1700#'s.! You have got to take a peek at the design...do you have FreeShip? I would be happy to post it...just remember it is rough right now.

    I will not argue that the smaller, the less stable. That is why "stability" must not be a consequence of the design, it must be maximized by designfor the restrictions of the design instead of just throwing weight and size into it. This sounds easy, but I am really hurting. Every extra 1 inch is a 3 inch nail in the coffin!!


    Yes...rigging sure sounds like it will be a real whopper and I'm anticipating it so I want to make verything as simple as possible. I remember seeing quite a few good you-tube clips of excellent mast raising systems that were so simple that I caught flies from my mouth being open.

    I don't think it will be too much of a problem with the technology and geometrical understanding of today. Take a look at this link and click on the pictures to see the system being raised in one shot...the guy never left the cockpit!!! Unbelievable! :eek:

    http://osyc.net/photos/2005-11-Smiths-Telstar/page_01.htm


    The section is unavoidable because of the moments. The length for the designed mast is 1.3x of LOA. It produces a good aspect ratio, keeps the CE low to moderate and it keeps the mast on the trailer within the 3 foot "red flag" rule for items extending beyond trailer length. It's a very nice compromise for a cruiser.


    I suspect you may be right in 2008...and GOD willing you will be around in 2038. How would you word it in 2038 if it did get off the ground in 2009 without 30 years of evolution?:D Everything starts somewhere or sometime and by someone.

    We cannot believe that something will not exist, or evolve just because something exists or has evolved already. Do you believe that the current designs available will exist forever and no other design can ever evolve or exist just because their designers perish or do you believe other, new designers may take their place and create new designs or evolve old designs?


    I get caught up in numbers because they give a good idea of the design and the mistakes are kept on paper. All designers design before they build right?Car fuel consumption will be 10 times less than a winter season of berthing in the same place and restricted to the same area. If you berth in Alaska, you could go out in the winter but probably not, unless you trailer to Florida. Comfort is a must, but open to many definitions. The designed comfort will be either accepted or rejected by the prospective owner...just like the same comfort may or may not be rejected for a 38 footer.

    I've been on a couple of boats and I'm always thinking critically, but I don't really want to base the concept on anything out there because it is a middle of the road concept with a little of everything, but it is radical and nothing out there really fits it. Besides...I have lots of time to design my own. In reality, I have studied and read many authorities on the subjects, so, I guess I already am doing that.

    I believe I know what I want, but it's a working progress, taking and giving a little as I go along until I reach a happy medium. For example, 26' LOA was minimal, then I thought that 27' would gain some more waterline for the same weight by the square, volume by the cube and costs would be minimally increased and the extra foot wouldn't create too much more trouble trailering.


    I have been studying and learning works of many respected and accomplished designers, and many other less notable but as brilliant, for about 4 years now, along with everything else I can get my eyes into in between, so I agree I have little experience compared to many. Knowing my limitations, I would want to engage more experienced than I to help me to avoid pitfalls. I don't need to go to medical school and become a doctor in order to provide a remedy for my grandchildren.

    But I bet that a doctor will come to me when he wants to develop and structure a 30 million dollar project underwritten with only 3% equity, of which I will provide in kind from other investors, with a full dollar for dollar tax-credit reduction for any business he may have for 15 years, with zero tax liability after selling at full profit after year 16, while being able to retain any cash value the project has generated as a gift for his generous 3% equity which other investors gave him in kind.


    I appreciate that you share your thoughts and I do not view them spiteful or malicious. Do you have any pictures of the design? I would be interested in seeing it. Sailing is waaayyy more fun than designing and building. We retired early and did a lot of it, then we came out of retirement, (my father and my mother in law were terminally ill and required our full attention and presence until their passing) but we plan to retire early again in about 5 years to do it some more. I sail as much as I can right now, but it isn't as much as I would like.

    The operative words are "retiring in order to sail"!

    Well...please continue to "stalk" the thread, but know you are welcome to contribute anytime.

    Thanks
    J:cool:
     
  5. JCD
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    JCD Follow the Bubbles!

    Hello Richard,

    This is rough, but inevitable. Built to specs, by pros capable of providing the statement to obtain Category B rating...Durakore and glass.

    Trailer and ocean not included.:D

    Cost per LOA' $1,809.55 x 27 = $48857.85

    Thanks
    J:cool:
     
  6. Richard Atkin
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    Richard Atkin atn_atkin@hotmail.com

    J, I like your determination. If you can make the sliding system super-reliable, then I think the boat will be a whole lot of fun.

    I don't mean to hijack you with all this elementary stuff...just a couple more questions:
    The speeds shown in the spreadsheet all represent boat speed...and not wind speed, right?
    Are you able to estimate how fast your and my boat should go in 8 knots of wind (typical California summer wind), and then again at 15 knots (nice sea breeze)?
     
  7. JCD
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    JCD Follow the Bubbles!

    Hello Richard,

    Not at all a hijack. Yes, speeds are boat speed exept stability speed and reef speed which are wind speed in knots and denoted by their F designations. Before I move on, I looked at the second page of the results for the AtCat and the heading said the results are for the trailerable. The results are accurate for the AtCat, so disregard the heading or change it to the AtCat. Sorry.

    SA/D ratio is similar to the HP to weight for cars. The Bruce number is also a power to weight ratio. In your case, it is 1.27. There is some controversy that 1.3 or less denotes poor performance in light winds and another stating that 1.0 is the line between poor or good performance. For me, the SA/D ratio is a better measure because it allows all combinations of sail as oppossed to the Bruce number which does not allow overlapping sails and calculates only main and jib triangles. I’m sure that tedious calculations can produce answers to your questions. I never really considered figuring that out. Sorry again. I think VPP’s are the easiest way to get an answer, although polar charts for designs have been calculated by NA’s long before VPP’s. I suspect it isn’t easy and expensive and probably only important to racers looking for that milli-knot advantage. I would suggest that you give Rick a loud ping and ask if he has some time he can spare to give you some results.

    I am more interested in establishing how much sail area was required to operate the specific designs safely to F8, which is a Category B requirement and the maximum amount of possible sail the design should carry for light wind performance. I wrote a spreadsheet that produces the answer to that kind of concern. Perhaps this may be more of interest to you. Now, based on the AtCat specifics, the results are the following.
    F8 in Knots (34-40)
    40Knots
    Total Sail Load 2620.48
    Per sq. ft.6.896
    F5 Sail Load to Lift Hull 456.0153
    Per sq. ft.1.20004
    Sail Area To Lift Hull 66.1275
    Max Sail Area (Reef) 52.902

    To help you read the results.
    Your sail area would experience a total wind load of 2,620.48#’s at F8 and it translates to 6.896#sq.ft. at F8 wind speed of 40 knots. The maximum sail area to lift the hull based on load on the sails at F8 is 66.1275sq.ft, but the maximum sail area that you should have by reefing at 80% based on the F8 load is 52.902sq.ft. Your stability wind speed to lift the hull is at F5 with a wind speed of 16.68 knots and the maximum total wind load experienced on the sails is 456.0153#’s and it translates to 1.2#sq.ft. Knowing both of these, you now know that:

    1. The maximum sail area deployed at Force 5 (16.68 knots) will be 380sq. ft to lift the windward hull.

    2. In any Force condition, the load experienced on the total sail area for your design can never be greater than 456#’s because it is at that point that the windward hull lifts and RM is at its greatest. Conversely, a lesser load would require more canvas to lift the hull.

    Now…here it is for F5 (16.68 Knots). Notice that the total load on the sails are equal.
    F5 in Knots (16-21)
    16.68627Knots
    Total Sail Load 456.0153
    Per sq. ft.1.20004
    F5 Sail Load to Lift Hull 456.0153
    Per sq. ft.1.20004
    Sail Area To Lift Hull 380
    Max Sail Area (Reef) 304

    Anywhere between 16.68 knots and 40, you can find the required Sail Area that will never exceed the 456.01#’s required to lift the hull based on the formula for wind speed. The formula, although pretty accurate, is oversimplified so these are very close but rough estimates. It is based on the following... V^2*SA*.00431. There are close variations but this is close enough.


    At 20 knots, total sail load is 655.12#’s for F8 and you need 264.51sq.ft.of sail area to reduce it to 456.01#’s to lift the hull and 211.60sq.ft. for an 80% reef.
    F5 in Knots (15-21)
    20Knots
    Total Sail Load 655.12
    Per sq. ft.1.724
    F5 Sail Load to Lift Hull 456.0153
    Per sq. ft.1.20004
    Sail Area To Lift Hull 264.51
    Max Sail Area (Reef) 211.608

    At 25 knots, total sail load is 1023.62#’s for F8 and you need 169.28sq.ft.of sail area to reduce it to 456.01#’s to lift the hull and 135.42sq.ft. for an 80% reef.
    F6 in Knots (22-27)
    25 Knots
    Total Sail Load 1023.625
    Per sq. ft.2.69375
    F5 Sail Load to Lift Hull 456.0153
    Per sq. ft.1.20004
    Sail Area To Lift Hull 169.2864
    Max Sail Area (Reef) 135.4291

    At 30 knots, total sail load is 1474.02#’s for F8 and you need 117.56sq.ft.of sail area to reduce it to 456.01#’s to lift the hull and 94.04sq.ft.for an 80% reef.
    F7 in Knots (28-33)
    30Knots
    Total Sail Load 1474.02
    Per sq. ft.3.879
    F5 Sail Load to Lift Hull 456.0153
    Per sq. ft.1.20004
    Sail Area To Lift Hull 117.56
    Max Sail Area (Reef) 94.04801

    At 35 knots, total sail load is 2006.305#’s for F8 and you need 86.37sq.ft.of sail area to reduce it to 456.01#’s to lift the hull and 69.09sq.ft.for an 80% reef.
    F8 in Knots (34-40)
    35Knots
    Total Sail Load 2006.305
    Per sq. ft.5.27975
    F5 Sail Load to Lift Hull 456.0153
    Per sq. ft.1.20004
    Sail Area To Lift Hull 86.37062
    Max Sail Area (Reef) 69.09649

    Notice that the reductions are not linear? That is because velocity for the wind speed increases/decreases by the square.

    Let us now assume that the wind pipes down to below the AtCat stability speed to lift the windward hull of 16.68knots. That would mean you have to add canvas. Assuming that you can, by way of larger Genny or Spinnaker etc., and the wind speed is now 10 knots (F3 – 7 to 10 knots).

    At 10 knots, total sail load is 163.78#’s for F8 and you need 1058.04sq.ft.of sail area to increase it to 456.01#’s to lift the hull and 846.43sq.ft.for an 80%reef.
    F3 in Knots (7-10)
    10Knots
    Total Sail Load 163.78
    Per sq. ft.0.431
    F5 Sail Load to Lift Hull 456.0153
    Per sq. ft.1.20004
    Sail Area To Lift Hull 1058.04
    Max Sail Area (Reef) 846.4321

    By establishing the greatest sail area possible that the design can carry, you can now establish what will be the least wind condition in which the design can operate to lift the windward hull. Way will be maintained below that maximum sail area, but if the wind speed gets too low, you would want to decrease the wetted area by flying the hull, if it is possible to do so.
    Here it is for F1, 1-3 knots. Ridiculous and I suspect she will be a dead stick.
    F1 in Knots (1-3)
    1Knot
    Total Sail Load 1.6378
    Per sq. ft.0.00431
    F5 Sail Load to Lift Hull 456.0153
    Per sq. ft.1.20004
    Sail Area To Lift Hull 105804
    Max Sail Area (Reef) 84643.21

    All of this is based on sound mathematics, but they are strictly maximized theoretical results only on paper. Have some fun anyway.

    Thanks
    J:cool:
     
  8. Richard Atkin
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    Richard Atkin atn_atkin@hotmail.com

    That gives me a very good perspective. Thanks again J.

    As you imply, rules are only guidelines, based on the rule-maker's assumptions of what a typical boat should do. This will always lead to controversy.
    I believe a design process should be steered by the goal in mind, and not by rules of thumb. The rules should be there only to stop you steering too far off course while the final picture is still hazy.

    With the Atcat hulls being canoes optimised for 8 knots, I am happy with the stats you provided, and don't intend to change anything! :) That is....until some naval architect slaps me over the back of the head.
     
  9. Richard Atkin
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    Richard Atkin atn_atkin@hotmail.com

    Rick posted this ages ago in my thread:

    Richard
    It is not built yet so we are speculatiung or predicting. Whichever term you prefer.

    With that area in the form of an EFFICIENT sail I determine you would need around 12kts of wind to do 8kts. This is on the basis of the boat sitting with level trim. It would not take much weight to do this. It might actually do a bit better if you move weight around to load the lee hull but then the analysis gets more complex.

    The sail efficiency improves if the foot is closer to the deck but I do not have a means of calculating the benefit. I am sure there is someone else who has better knowledge of sails.

    8kts is not much wind. This is the Beaufort description:
    "Small wavelets, ripples formed but do not break: A glassy appearance maintained."
    If you intend to only go out in these conditions you will not get much use out of the boat. In 8kts of wind you could expect about 6kts.

    I would be interested to see what sailing prediction software produces for the hulls with 300sq.ft sails. I determine you would need around 450sq.ft to get 8kts in 8kts breeze.

    Rick W.


    I have 380 ft2 sail area now, so if the boat does manage to do 6 knots in 8 knots of wind, then I will be more than happy....particularly because the places I would like to sail to don't have strong currents, and the wind is usually 7 to 10 knots at the windiest time of day.

    I just included this post incase it had any relevance to your design.
     
  10. JCD
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    JCD Follow the Bubbles!

    Hello Richard,

    You're welcome.

    The way I figured, by knowing the maximum canvas you can bend based on the wind speed, you will always be on the safe side and never overcanvassed and, since you will always be flying the maximum area for the wind speed, you will always be at maximum hull speed. Did that make sense? I hope it did.

    If we as amateurs can get these kinds of results, which are not unrealistic, the NA's and NE's can do it better, but those slaps in the back of the head should be taken with honey...they may be the ones that saves our life!

    J:cool:

    Okay...Hello to one and all…

    Did some work in the hulls to try and figure out the structural locations. Anybody have any comments?

    Here is what I have so far. Long is longitudinally and wide is traversal. The hulls will be symmetrical.

    I thought about making 1 hull with 1 head and 1 berth at oppossite ends, and 1 hull with 1 galley and 1 salon at oppossite ends, and it may still come to that, but then I thought about the coastal and inshore cruiser. They may want to have a couple as guests for overnighters and may not need the "full" offshore cruising capacity and the extra bunk and head comes in handy, so I kept them.

    The aft bulkhead, air and water tight from inside is located at 5’. The outboard motor in a well is 9.8HP with 12 gallons of gas with access only from outside.

    There is a 2.25’ wide x 1.25’ long head settee with 5gallon potti beneath which may be plumbed or removable. The distance from the settee to the berth is 2.1’, which will probably be the curtained shower area. Stand or sit to shower.

    The foot of the berth acts as a settee 2.6’ wide x 2’ long. The berth is 3’ wide at the head and 6.5’ long. Headroom is 2.2’. Less headroom is okay and will provide a 3.6’ wide berth. Tankage will go beneath and includes a 6 gallon hot water heater and a 45? gal water tank. Maybe a water maker for emergencies can be installed in one hull? The rest of the storage will be used for other items.

    The second bulkhead starts at 10.34’. The cockpit is above and it is 6.25’ long by 2.5’ wide, but I haven’t removed the inboard side for the cuddy to slide yet. Once it is done it will be 3.25’ wide. The cockpit seating will be modular or it may fold up.

    The aft companionways will give access to the cuddy when it is retracted into place and the forward companionways will not, but they will give access to the hull by a sliding companionway hatch when the cuddy is in place.

    Moving forward, the third bulkhead is at 16.6’ and gives access to the galley which is buried beneath the cockpit 1.75’. The countertop is 3.4’ wide and will hold a 2 burner stove and sink with some working room for food preparation. Stove clearance is about 1.8’. The bulkhead will have a sealed hatch for quick escape from the berth if needed and provides a means to do some minor stove duty from the berth in case it's a lazy start to the day and you want some coffee before going topsides, or a warm glass of milk at night before going to bed. The galley cabinet beneath provides about 9 cubic feet some of which may be taken up by the dagger/lee trunk down the center line if the concept works, so that if the hull is breached by a hit to the board, the cabinet can be sealed.

    Moving forward, the distance from the galley to the aft salon settee is 1.65’. The fixed, full width settee is 2.5’ wide by 1.25’ long with ice box storage of 4.5 cubic feet underneath. Without a back, it can be used to sit forward or aft for eating or for cooking. Installing a plate would provide a refrigerated volume of 3 cubic feet?

    The distance from the aft settee to the bow settee is 1.5’. The settee is fixed for the full width and it is 1.5’ long by 2’ wide. Storage beneath provides 3.3 cubic feet which may be used for the compressor? The final watertight bulkhead (crash bulkhead) serves as the back for the bow settee and is located at 22.5’.

    Forward of the crash bulkhead, there is an anchor locker above and a sail locker or light storage beneath it accessible from a sealed hatch. Beneath, there is a horizontal bulkhead .5’ above maximum waterline for watertight integrity in case of a floatsam crash.

    All furniture is full width and fixed with access from hatches above the highest waterline. Is the compartmentalization that is provided in case if the hull is breeched too much?

    The bottom is flat for an aft run and I didn’t want to use a sole so I kept areas where soles may be located small and limited to the shower and galley. Anybody see a problem there?

    Anybody have an opinion on the accommodations and whether it is thought out enough to get the maximum use for the space provided without impinging on comfort?

    Thanks
    J:cool:
     

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  11. Richard Atkin
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    Richard Atkin atn_atkin@hotmail.com

    J, I think it's great. Very cosy, and interesting feel, and good privacy. I really like it. My only suggestion would be that you design the aft pink seat to slide towards the stove after cooking, so 2 people can sit and face each other for dinner etc.
     
  12. JCD
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    JCD Follow the Bubbles!

    Ahoy there...:D

    Cozy is an understatement. There will definitely have to be some transportation coordination with the first mate. On the bright side...you will always be "intimate" close.

    I apologize I didn't explain it clearer. The aft salon settee is fixed and will contain the ice box or refrigerator beneath. There is enough room there for someone to face aft and rest or cook, sitting, or standing with the hatch open, or to sit facing forward and enjoy dinner or a conversation face to face.

    I have included the hinged dinner/nav table I drew last night which will fold all the way to the other end instead of to the centerline, or it can be stowed up when not in use. It appears that everything I have/will be designing will have to serve dual purpose and somehow disappear when not needed if it is going to work for this design size.

    My limited experience in getting 3 cubic feet out of 2 cubic feet is a struggle to get all these different "proper" necessities to hinge, fold, slide etc., so that they serve their purpose.

    I have included some pictures with one of Yipster's little persons for better perspective. His name is Richard Atkin and he flew in last night from NZ to check out the design:D

    I hadn't used the little persons yet because I wanted to get the interior close first, but upon closer inspection it appears that I may have to lower those settees a little bit because their feet are not on the sole and a little more headroom is always good. His scale is 6' tall and 2' wide.

    So far...the first mate approves and is very impressed, but she is whinning about some cabinetry in the galley and berth and a sink in the head. That sounds like it is going to be a mission with only 4 feet of beam overall.

    Let me know if that provides some clarity to your observation and if you find anything else that I should look at.

    Thanks
    J:cool:
     

    Attached Files:

  13. Richard Atkin
    Joined: Jul 2007
    Posts: 579
    Likes: 18, Points: 0, Legacy Rep: 219
    Location: Wellington, New Zealand

    Richard Atkin atn_atkin@hotmail.com

    Hi J
    The man will have to grow some decent thighs before he can be called Richard Atkin. I do a bit of cycling.
    I think there should be at least 2 feet between the two seats, to avoid kicking toes.
    It is surprisingly comfortable to sit very low, even slightly less than one foot from the floor, because the knees bend up easily. Keep that in mind. You should practice sitting in small spaces by moving furniture around in your home.
    I think the kitchen/dining area will be a place where people sit for extended periods of time, so you should focus on comfort. There's nothing comfortable about sitting with a dead-straight back for an hour. Slumping forward is OK for eating, but not for socialising.
    If it was my boat, I would extend the hull another foot, just to make the kitchen/dining more comfortable, and I would include a flip-out back support for the aft salon settee. The closer you can get those settees to being like something you would see in your home, the better. You will be so glad you put in the investment.
    That's my opinion :)

    As I said, I really love the general layout, and if I was designing a proper cruiser for myself, I would steal it (with or without your permission, but I would ask first) :D
     
  14. catsketcher
    Joined: Mar 2006
    Posts: 1,303
    Likes: 144, Points: 63, Legacy Rep: 790
    Location: Australia

    catsketcher Senior Member

    A different drawing please

    Hello all,

    I can't get a good idea of the accommodation without a top view. However my two cents are.

    I really dislike the little dinette idea. We had a bigger one on my mum's 25footer mono and it was too small to use. MY 31 ft Twiggy was very small and had a bench seat running fore and aft. A lift up table came up from the hull side. This is usable and doesn't stop you moving forward and aft.

    How do you get into the little seat? Do you come in from up top or from aft? If from aft you have to jump over the seat. This is sucking defeat from the jaws of victory. If you go the bench seat then the bench will provide a way of moving fore and aft on your bum and sliding - good in a seaway. It also provides a great re-inforcement for the hull bottom for trailering.

    As for the rest I can't really tell. Is the middle section the cockpit? I went through the thread and couldn't see the model. Could you tell me where it is?

    cheers

    Phil Thompson
     

  15. JCD
    Joined: Jul 2006
    Posts: 359
    Likes: 3, Points: 0, Legacy Rep: 36
    Location: Coney

    JCD Follow the Bubbles!

    I will consider how else to provide that space, but pushing the settee aft will give less than 1.6 feet clearance between the settee and the galley. There has to be some room to cook and making the settee movable is not an option if it is to provide an ice box or refrigerator. Intercrossing legs is also an option, but you have to remember that it is a minimalist trailerable.

    I agree. Comfort, reasonably expected, has always been my priority. Why would the person have to sit with a dead strait back? They can straddle the settee and use the in/outboard bulkheads for back support. But again, it is a valid observation and i will definitely look ta providing vertical sliding backs for that settee forward and aft so that either can be used as a back suppot.

    I am trying to work within the "minimal" trailerable restrictions that I have set for myself. I already increased the design to 27 feet. I don't believe that another foot will keep me honest within the restrictions because then I might as well add another foot for the galley, another for the head, another for the berth and another for the engine room and that now makes 5 single foot increases. Unless there is an overwhelming safety concern, which I don't anticipate because it will be designed as Category B, the design will be 27 feet. Even that size could be a problem to trailer.

    Thanks. I am amazed that I was able to fit so much in that little 4 foot beam with no less than 2.6' of traverse distance in any free space. I think that Richard, the other Richard, made me work hard at that when he mentioned the "proper" word comparing comfort. I see everything in this size as minimal for the design restrictions, but damn, I liken the "amount" of accommodation to a much bigger boat. I definitely gave him the "proper" shower at 4' x 2'. The volume is huge!

    Okay...I will look at those things and will definitely advise. On a positive note, I have done some more work and will provide those addittions very soon. I think that will be then end of the accommodations after that. Every possible thing that could be required or needed for offshore comfort has been incorporated and I am still amazed that I was able to do it.

    Thanks
    J:cool:
     
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