35' cat concept for the inside passage.

Discussion in 'Boat Design' started by Boston, Dec 6, 2011.

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  1. michael pierzga
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    michael pierzga Senior Member

    And there are many ways for " wise guy " highplains drifters to beat the dockage game.

    In season I always use commercial docks. Perhaps 50euro per night , at the harbourmasters discretion.... rat proof the yacht.

    Many highplains drifters "bunk'a down " at disused military facilities when the incoming waves of blow ins surge and drive up the dockage fees. They call them bat boats because the bunkers are full of bats that poop on you. Wear a wide brim hat

    To be a wise guy you need a seaworthy tender capable of two or three mile open water runs..
     

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  2. Boston

    Boston Previous Member

    interesting stuff Michael,

    I drew up a plan and an elevation showing the elongated deck house. Its a lot more room just adding two feet. I didn't jam in the door yet but I'm working on it. The longer design looks blocky though. I'm thinking I might slide the whole deck house forward a bit more and add the 2 feet back onto the aft deck. Also might take the round form of the forward window and bring it out to the edges, sorta like a lot of the cats you see but not with the huge rake, IE slopping surface up to the roof, = space ship again. Might try one with a forward raking pilot house window tho. Although it might detract from the overall style I'm after

    [​IMG]

    I didn't finish the plan view, so don't focus on the lay out, but the galley and bed area as well as the forward pilots group worked out well. I could pretty easily get the four pilots chairs in a thinner space as well as just about everything else now that I've elongated the area. I know the suggestion was made to widen the cabin, but I'd save weight and still have all the room I need by narrowing it a little. That and get a nice comfortable cat walk forward to tie off, since I've not worked out that forward hatch yet.

    [​IMG]
     
  3. michael pierzga
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    michael pierzga Senior Member

    In general I like the concept of a reasonbly seaworthy , motorized cat houseboat. A house on hulls, so that you move..relocate..as the season or circumstances change. Max house, max livabilty, max utility.

    Keep sketching.

    Im really surprised that others are not exploring this concept. Some time ago I saw that resident Boatdesign.net NA, Eric Sponberg, was expolring this concept. Would be worthwhile to run it by him
     
  4. groper
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    groper Senior Member

    Boston, seriously mate, when youve shown the "beds below" in previous sketches, how do you think you going to fit them in there? You need at least enough height to sit up in bed and to fit a double bed in the hull, it has to go at the same height as the bridgedeck, a double wont fit down lower in the hull than this... Even more so, with vertical hull sides, you have even less space... The only cats under 40ft ive seen that can fit a double bed in the hull, have alot of flare in the hull and the bed sits around bridgedeck level at the widest point. They usually are stern of midships with the engine underneath the bed. The other common place to put the beds, is up the front between the tunnel and the foredeck, again with sitting room only. So unless you design the whole thing with more air draft and go up higher, your pretty much limited to this apart from a bedroom on the bridgedeck like youve shown in the last drawing. The thing with this is, how much time do you expect people to be in bed? It occupies alot of good realestate that could be used for living spaces that get used all the time, for something that i would only use to sleep in at bedtime...

    All of these sketches dont make very good use of space... so far im yet to see anything thats workable im sorry...

    Houseboats, generally have alot more height, are longer than 35ft, and certainly do not go into openwater... In order to live on a boat in this size, you really have to make very efficient use of space, dont waste the space in the hulls like a houseboat on pontoons does...
     
  5. Alik
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    Alik Senior Member

    So double bed is in trunk? How to get to seats in front, there is no passageway between? Bathroom area - it will be a disaster to open those doors. Where is dining area? What guests see when the first enter the boat - do they see narrow corridor and plenty of bulkheads, no feeling of space?

    I would make stern area of superstructure all master bedroom with panoramic view, and front area saloon with steering station. Toilet can be between them. Look at attached sample, but pls note this is 60' sailing boat. This is just some picture to illustrate the idea of how designer can use space...
     

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  6. Boston

    Boston Previous Member

    I've figured out the head room in the hulls long ago Groper. It sucks but its adequate. Its the width that changed, which changed in order to try and maintain some kind of efficiency, as did the weight. I'm 6'1.5" and I don't like bashing my head on stuff. So head room is a major issue, that I'll bear in mind one way or the other :D.

    At this point in the development your right about not being able to jam a double into the hulls. They were 5' wide with very little draft when I started, but it was pointed out by someone that narrower and slightly deeper hulls would be more efficient. Which struck me as odd given how easily a sharpie form is driven. And I wanted sharpie type hulls. The hulls are now only 3.5' at there widest point. with either 6' 1.5" or 4' 9.5" ' of head room. Minus framing.

    Means I have to start thinking of moving the bath up to the bridge deck. That or get used to the idea of siting down to take a shower, which just seems wrong for some reason. Might be the difference between lifting your leg or squatting to pee. :p:p:p

    The optional head room being if I decide to foam fill or not. I could create a hull that would remain floating on her lines even when holed used a foam fill method of constructing the submerged areas. Means less head room bellow. So the bed areas bellow would be singles and have enough area to at least sit up. But moving around down there would be a pain in the ***. It was a compromise I didn't want to make but seemed reasonable for the sake of mileage.

    The latest incarnation

    [​IMG]

    I'm not constrained to 35' and the whole thing works much better at 40' or just under, but I do want to keep trying to jam it all into 35' and see if I can't make it look like something. Course thats subjective but still, It would be interesting do deviate from the typical space ship looking thing. At 40' I could easily have a hatch going forward off the port or starboard side with a set of steps going up and a hatch out to the cat walk ( pun intended ). A bath on the bridge deck, and room to spare, as well as almost enough head room in the hulls.

    Just saw your post Alik, no fair showing off a 60 footer. Of course there's lots of felt on a boat that big. Sorry pool term, a lot of open area. With the hulls at only 3.5' wide the double bed has to move onto the bridge deck somewhere, unless I want to be sleeping in a cave, which I don't. The seats in front swivel on an asymmetric base, so they move off to the side as they turn. Leaves plenty of room to get in and out. You did catch the part about that last floor plan not being complete didn't you. The dining area is behind the front seats, which swivel around and become dining chairs as well. The couch is also additional dining seating and the chest that goes between all has a removable lid so it doubles as a foot rest and as a dining table. And I'm working on how to get rid of the walls around the double bed without leaving it exposed to the kitchen. I was thinking of an old style flip up bed that looks like a wardrobe when its up and a bed when its down. Or something like that. Not sure yet.

    since I have more buoyancy in the hulls than I need now that I'm aiming for <5 tons I'll probably skinny up the hulls another half a foot and resign myself to a bridge deck bath area. Rather than jamming it bellow somehow
     
  7. michael pierzga
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    michael pierzga Senior Member

    And " doors" make small boats even smaller. Also investigate ways to eliminate doors.
     
  8. groper
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    groper Senior Member

    Boston, i fail to see why you persist with those hulls, at least put a decent knuckle in them to give some more volume above the waterline... you could do a square knuckle to preserve the boxy "anti spaceship" style... or a more rounded knuckle like this...
    [​IMG]

    Either way, you need more volume in the hulls to make them useful...

    Have you tried putting the beds in front of the coach house, between the tunnel and front deck? you could add a little raised front deck to provide the headroom above the beds, only need about a foot or so more, then the front cabin windows look over this... have to shift the whole coachhouse aft, then you have access via the hulls into 2 forward bedrooms either side of the helm and bathrooms midship hulls... kinda like this;
    [​IMG]

    And with your style in mind, you could continue the back deck all the way flush with the stern of the hulls, although this is normally where the tender is kept, you could hang it proud off the stern...
     
  9. Boston

    Boston Previous Member

    Hmmm, you must not have read the whole thread, or that would be my guess. The hulls are intended to be a Bolger style sharpie form, because that shape is about the most efficient mover. A great man once said, "you can piss off the back of a sharpie, and make it move" Might not be an effective cat hull. But its damn efficient as a sharpie. So not having any experience at all with cats I though I'd start with a hull form I knew to be efficient, easy to build, really easy to fix, and with shallow draft. Also typically has a pretty stoutly built bottom, which is something else I find appealing since I want a beachable boat. Which is why I was surprised to hear someone say that a deeper narrower hull would be better. Course now I'm hearing a composite shaped hull but to each his own I guess. I'm not seeing where that hull shape is all that conducive to ply construction. Which again might be a function of not having read the whole thread. Also that shape subtracts from the bridge deck area, If I wanted to make the boat bigger I'd just go Titanic and have all the room in the world. The idea is can you jam all this stuff into a 35' cat and still have a nice open design thats comfortable to live in and has room for guests.

    There's a development of an idea going on, not a final product being proposed.
     
  10. groper
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    groper Senior Member

    Mate, ya gotta start reading between the lines ya know... it was just to illustrate the "knuckle"... the underwater shape doesnt have to change at all, but see how much volume it adds above the knuckle? Now you can start to fit things in your hulls...
     
  11. michael pierzga
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    michael pierzga Senior Member

    Besides BUMPS , tumblehome are a game. You get a Wide hull, narrow deck. Go max beam and slab sided if you want the most usable liveaboard boat.
     
  12. Boston

    Boston Previous Member

    I tried drawing up a few with slab sides but damn were they ugly, floating brick looking things. Not what I was after at all.

    Groper, I tried to eliminate the coach house, or at least keep it as small as possible thinking that the more hull I had forward before I got to tunnel the bigger the hole I could nose dive into and still come up with a boat. But that was another suggest that I bridge over the open area I had left between the forward part of the hulls. I'm just waiting for someone to tell me I should lower the tunnel some.
     
  13. Richard Woods
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    Richard Woods Woods Designs

    You say a Sharpie hull is easily driven. But its not as good as a kayak

    Richard Woods of Woods Designs

    www.sailingcatamarans.com
     
  14. groper
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    groper Senior Member

    I reckon you can lower the tunnel to 32", i wouldnt go below that... Many good cruising cats use 32" clearance, although you have to be careful that this isnt too close to the bow or you will still get slamming... thats why i said you will need to move entire cabin aft, but at least both your beds are in. You might need to raise the foredeck a touch to allow headroom whilst in bed tho, you can include a fancy set of portholes along the raised area to let light into the bedrooms... looks classic and functional...
     

  15. Boston

    Boston Previous Member

    Working on it. But I'm not sure which floor plan your looking at. Tunnel is at 31.5 inches. pretty sure I mentioned that earlier.

    Hey Richard, good point about the kayak but the sharpie form is more easily produced in plywood.

    [​IMG]

    The bed flips up into the dark rectangle area just at the head of the bed. The base is faked in to match the wardrobe at the foot of the bed. Other than cabinet doors the only door in the whole thing is the bathroom door. Well that and the back door. The decorative table behind the couch could be eliminated but there's a lot more room in this space than whats indicated by the layout. For instance those recliners are huge. I've got four nice sized recliners lined up and looking out a picture window now and they don't take up 13' like the ones on my drafting template would indicate, even though they are supposed to be 1/4 ~1' scale. So there's plenty of room for the chairs and probably even a set of steps going up to a forward hatch disguised as one of those windows. But with a sliding hatch over it. Hate chopping holes in my roof though. With the present width of the hulls I'm stuck with a number of single berths in the hulls,
     
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