rustybarge
Well-Known Member
Curved screen something like this?
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Help Design my Boat.....please!
- Thread starter rustybarge
- Start date
rustybarge
Well-Known Member
Big pulpit bow rails seem to break up the blocky front view.
View attachment 35462
View attachment 35463
In blue..raising the bows and leaving the center in white hides the boxy look?
.View attachment 35461
View attachment 35462
View attachment 35463
In blue..raising the bows and leaving the center in white hides the boxy look?
.View attachment 35461
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Bajansailor
Well-Known Member
I think that I would prefer to have a raked front screen rather than vertical.
Am not too keen on the pulpit rails you have sketched in, although I realise that they would be a good safety feature.
Maybe consider a rail similar to the type seen on pilot boats (like an oversized handrail), where the person walks on the outboard side of the rail?
Am just wondering, what is your intended usage with the boat?
And will you be keeping a single small O/B motor on the centreline, or going to twin engines later?
Is yours the 7.9m model?
http://www.cheetahmarine.co.uk/en/gallery/view/12/
Am not too keen on the pulpit rails you have sketched in, although I realise that they would be a good safety feature.
Maybe consider a rail similar to the type seen on pilot boats (like an oversized handrail), where the person walks on the outboard side of the rail?
Am just wondering, what is your intended usage with the boat?
And will you be keeping a single small O/B motor on the centreline, or going to twin engines later?
Is yours the 7.9m model?
http://www.cheetahmarine.co.uk/en/gallery/view/12/
rustybarge
Well-Known Member
Unfortunately i have the smaller 6 series model (stretched to 7mtr), which accentuates the the high roofline because the freeboard is much less. The boat is a mini- livaboard that fits in a shipping container at 2.34 mtr beam, so i can send it by box container for the long sea trips at very cheap rates. First trip hoping to ship Ireland to Gibraltar to cruise the west med. the next model up the the 7 mtr series is too wide at 2.5 mtr.......
Lot's of fishermen use just one 90 hp outboard, saving 20% on fuel over twins.(with a small standby)
Bajansailor
Well-Known Member
I'm just wondering, as you will have to use a 40' container (rather than a 20'), would it have been a huge extra cost if you had a 40' flat-rack instead of a container? A wider cat would overhang on each side of a flat-rack, but I wonder if you would be charged just for the extra width, or if you would be charged for the space that could be taken by two other 40' containers port and starboard of your flat-rack?
Changing tack, re superstructures, here is some info on a little water taxi designed by NGAL in the 90's - the deckhouse on this craft looks reasonably stylish, and not at all like a shed, but she does have the huge advantage of being 2 m longer.
http://extranet.bmt.org/vessels/datasheet.aspx?v=23
rustybarge
Well-Known Member
Wow, that's an unusual boat.....uses the same Venturi effect with narrow space between hulls to damp slamming.
I've heard that if you send your boat as deck cargo everything gets stolen by the dock workers; at least my stuff will be sealed inside the container.
Re the styling, i think i'm going to have to raise the the bow section, and make the windows smaller to hide the boxiness....( blocks of foam or plywood?), and also extend the hull over the ally engine pods to make hull look longer and sleeker.
View attachment 35468
Like this.....
View attachment 35467
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rustybarge
Well-Known Member
Front view of the raised bows to match previous side view.....better?
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Bajansailor
Well-Known Member
Raising the sheerline would be a lot of work, and I am not convinced that the effort required would be worth the slight (if any) improvement in general appearance.
If you are going for 'solid' sides (rather than roll up canvas with clear windows), then the smoked windows and blue hull with white boot-top in post 20 looks pretty neat.
Here are a few other types of similar power-cat for reference :
Richard Woods is better known for his range of sailing cats, but he has recently designed a range of small power cats that are very economical on fuel - http://www.sailingcatamarans.com/index.php/designs/6-powercats
The solid wheelhouse on this 23' cat downunder looks pretty stylish - but yours would have to be a bit longer (?).
http://www.spiriteddesigns.com.au/?pageId=7268
Your sketches are starting to tend towards something like an extended cabin Noosa cat - http://www.noosacat.com.au/Noosa_Cat/Series/Pages/2700_Series_-_Extended_Cabin.html
If you are going for 'solid' sides (rather than roll up canvas with clear windows), then the smoked windows and blue hull with white boot-top in post 20 looks pretty neat.
Here are a few other types of similar power-cat for reference :
Richard Woods is better known for his range of sailing cats, but he has recently designed a range of small power cats that are very economical on fuel - http://www.sailingcatamarans.com/index.php/designs/6-powercats
The solid wheelhouse on this 23' cat downunder looks pretty stylish - but yours would have to be a bit longer (?).
http://www.spiriteddesigns.com.au/?pageId=7268
Your sketches are starting to tend towards something like an extended cabin Noosa cat - http://www.noosacat.com.au/Noosa_Cat/Series/Pages/2700_Series_-_Extended_Cabin.html
rustybarge
Well-Known Member
Thanks for those links.
I'm afraid you're right.
Side view looks ok.....
Three quarters view is ok.....
Rear looks ok as well.....
Front elevation is horrid, nothing much i can think of to hide it. The hulls are too small/narrow in proportion to the wheelhouse windscreen/ roof. Main reason is that the wheelhouse is so far forward, normally it's located much father back.
Only hope is bow rails and maybe a dodger attached to the stanchions to change the shear line, as you've suggested.
The Cheetah production 6mtr series has exactly the same problem...
View attachment 35489
The only solution, raise the both hulls above the forward deck level.
Another idea...make it look like an American pontoon boat at the front....one large vertical acrylic screen
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Bajansailor
Well-Known Member
Like the Cheetah shown in your post above, your cat would look much better I think if the sides were canted inboard a bit, rather than being vertical.
I was rather hoping that other Forumites might have chipped in here with their thoughts....... ?
A fairly wild idea - if you are not restricted on headroom by bridges, then the stability (as it is a cat) should be good enough to have a low profile flying bridge up top, and then that frees up the space in the deckhouse that would be taken up by a helm console.
There is a very long and detailed thread on the American Boat Design Forum about a chap in Australia building himself a 10 m displacement power cat, and doing a very fine job - http://www.boatdesign.net/forums/bo...displacement-powercat-build-thread-38588.html
It is 12 pages long already, and he still has a fair ways to go.......
I was rather hoping that other Forumites might have chipped in here with their thoughts....... ?
A fairly wild idea - if you are not restricted on headroom by bridges, then the stability (as it is a cat) should be good enough to have a low profile flying bridge up top, and then that frees up the space in the deckhouse that would be taken up by a helm console.
There is a very long and detailed thread on the American Boat Design Forum about a chap in Australia building himself a 10 m displacement power cat, and doing a very fine job - http://www.boatdesign.net/forums/bo...displacement-powercat-build-thread-38588.html
It is 12 pages long already, and he still has a fair ways to go.......
rustybarge
Well-Known Member
Your cat looks a bit bigger than mine. I love the idea of a flybridge, or even better one of those really high tuna spotting towers with a ladder and Bimini, ...........but I'm restricted to 1.5 tons including the engine(s), and the bare hull weighs 900 kg at the moment. That leaves me about 300 kg for the superstructure.......
What a build project, am I right in saying that he is going to have too sand down and fair the outside of the whole if the boat because it's not moulded in a female mould. How many square feet is that!!! Rather him than me.
The latest plan: Polycarbonate.
The best solution for the roof seems to be to cover it in polycarbonate sheeting, like they use for bus shelters etc.
It's cheap, strong, light and it's available in super reflective insulated sheets :http://www.fascias.com/contents/en-uk/d75.html
I am thinking about using the 25 mm sheet. Hoping to find a single sheet 6 mtr by 2.4 mtr.
Question: how would you fix the sheets to the aluminium frame?
rustybarge
Well-Known Member
Just a few sketches that are developing......
The side view:
The front view. Raising the two hull lines by building up with foam blocks placed on the original front deck:
Disguising the old low wing bridge by fitting a new cross tube connecting the two bows at the very front.
The side view:
The front view. Raising the two hull lines by building up with foam blocks placed on the original front deck:
Disguising the old low wing bridge by fitting a new cross tube connecting the two bows at the very front.
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rustybarge
Well-Known Member
..
There maybe a problem with using polycarbonate sheets on the roof...
Page: 19
http://www.accessplastics.com/wp-con...duct-Guide.pdf
Example: If the sheet length is 1000mm allow 3.5mm minimum for thermal expansion at the top. For sheets that are 6000mm long allow 21mm
for thermal expansion at the top.
Aluminium has an expansion coefficient of 2.3
Polycarbonate 6.7
21 mm expansion over 6 mtr, that's nearly 1".
If I glue the sheet to the ally frame, will it not buckle the polycarbonate with heat expansion??
Aluminium sheet rivited onto aluminium frame sounds good to me.
Next question: how do i waterproof the connections between the sheets of ally?
I'm going to go with Bajan's advise........
There maybe a problem with using polycarbonate sheets on the roof...
Page: 19
http://www.accessplastics.com/wp-con...duct-Guide.pdf
Example: If the sheet length is 1000mm allow 3.5mm minimum for thermal expansion at the top. For sheets that are 6000mm long allow 21mm
for thermal expansion at the top.
Aluminium has an expansion coefficient of 2.3
Polycarbonate 6.7
21 mm expansion over 6 mtr, that's nearly 1".
If I glue the sheet to the ally frame, will it not buckle the polycarbonate with heat expansion??
Aluminium sheet rivited onto aluminium frame sounds good to me.
Next question: how do i waterproof the connections between the sheets of ally?
I'm going to go with Bajan's advise........
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