Hunt for plans for flat bottomed hull

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Hagrid
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Hunt for plans for flat bottomed hull

Post by Hagrid » Sun Apr 08, 2018 8:20 am

I recently bought the PC 20 plans but have had a change of heart. I am looking for plans to build a flat bottomed hull approximately 40 ft by 13 ft (13 meters x 4 meters) I have looked but probably not looking in the right place. Can anyone point me to these plans if they are available or of course if they not, where I might find them.
I am planning to build a houseboat and because of height restrictions need to go with the flat bottomed hull as opposed to pontoons or catamaran. Unless of course there is a clever design using pontoons that will allow me clearance under a 8.2 foot (2.5m) bridge.

Thanks in advance



Jaysen
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Re: Hunt for plans for flat bottomed hull

Post by Jaysen » Sun Apr 08, 2018 8:57 am

Hagrid, are you talking about road bridges or over the water bridges?

If you are talking about road bridges, then I don't think any house boat will be able to be low enough to do that (unless we mean different things by house boat). If you are talking about over water, then you actually want to INCREASE draft (hull lower in the water) rather than decrease it (hull higher in the water). A V hull will sit lower and let you put the sole (floor) lower giving you more head room which means a lower ceiling. A flat bottom hull with sit right on top of the water pushing the ceiling (roof) higher off the water.

Basically I think you are looking for a V hull not a flat bottom.

But I may be completely misunderstanding the issue.

The other thing is that a 40' hull is BIG. Really Big. is the a full time live on you are building?

Hagrid
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Re: Hunt for plans for flat bottomed hull

Post by Hagrid » Sun Apr 08, 2018 10:39 am

Hi Jaysen
Many thanks for coming back to me .... apologies I should have been clearer yes it is a bridge in a tidal lagoon and at low tide I have about 2.5 metres from water to underside lowest part of the bridge. So concerned about clearance.

I am looking for LOA about 12 to 13 metres by Beam of 3.5 metres......see attached sketch of what I am hoping to produce. Yes it is big and want to spend some time on it with family and rent to guests in our guesthouse for overnight stays.
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Screen Shot 2018-04-08 at 1.31.01 PM.png

Jaysen
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Re: Hunt for plans for flat bottomed hull

Post by Jaysen » Sun Apr 08, 2018 10:54 am

I think you really want a displacement hull. I think Jacques or Evan would need to comment on it more as they are the guys whose plans you see here.

Hood luck.

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Re: Hunt for plans for flat bottomed hull

Post by Hagrid » Sun Apr 08, 2018 12:26 pm

Thanks Jaysen, I shall wait with baited breath.Jacques? Evan? can you shed some light on my predicament?

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Re: Hunt for plans for flat bottomed hull

Post by Hagrid » Mon Apr 09, 2018 11:16 am

So now my thoughts are sort of drifting towards a pontoon set up but one that will give me more less "Air draft" if that is the correct term to use. I would like to keep the draft of the boat as shallow as possible as we live on a very protected tidal inland lagoon and the freeboard to a minimum...... am I asking too much? Does anyone know of plans for such a hull.
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Re: Hunt for plans for flat bottomed hull

Post by Fuzz » Mon Apr 09, 2018 5:25 pm

A pure flat bottom barge style is going to give you the least amount of draft. I think if it were me I would look very closely at building a steel barge hull for something in the size range you are looking at. The decks and cabin could be built out of wood/epoxy if that is the way you wanted to go.

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Re: Hunt for plans for flat bottomed hull

Post by Hagrid » Tue Apr 10, 2018 6:38 am

Appreciate the response, may I ask why you are suggesting the steel hull, is it for the weight or the constructibility? unfortunately I am having to go the wood and glass construction..... May I assume that a non steel construction is going to sit high in the water giving me very little draft. I do have 2.5 metres between the bottom of the bridge and the water level (airdraft I think it is called) so thinking along the lines of collapsible railings on the sundeck etc. I guess what I am trying to decide is the comfort differences between a semi pontoon and a flat bottomed craft. I am fortunately on an inland lagoon with sea conditions being very low on my list of considerations.

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Re: Hunt for plans for flat bottomed hull

Post by Fuzz » Tue Apr 10, 2018 6:08 pm

My thought on a steel hull for your use is based on cost and ease of building in the size range you are talking about. I think there are many barges built in this size range so finding plans might not be too hard? Just my thoughts and they may or may not be correct :wink:

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