Home |
Search |
Today's Posts |
#11
![]() |
|||
|
|||
![]()
Now Andrew you had your chance to lead out your poison once again, now
tell me what pervert pleasure you display , tell me why you try ruin my reputation spill poison in a discussion --------- is this your best bid in this discussion well go back to hell and charge up your pover. |
#12
![]() |
|||
|
|||
![]() |
#13
![]() |
|||
|
|||
![]()
On Sun, 16 Jan 2005 09:14:52 -0800, "Brian Combs"
vaguely proposed a theory .......and in reply I say!: remove ns from my header address to reply via email You might try talking with the fishermen in the area since they have long experience of what shapes work and which ones don't work well for their waters. Then work from there. I agree. I see the boats they use, and they look very seaworthy in shape and design. And after all they are the one that are going to use them. It will be easier to persuade them to use the boats, and their lives are the ones at stake. |
#14
![]() |
|||
|
|||
![]() |
#15
![]() |
|||
|
|||
![]()
Hi
If you check the Cyber-Boat Yahoo group you will se pictures of several of the small boats I designed, build, sold plans for given plans away for. If you knew the old Cyber-Boat site you would have seen several more boats build ------ Now in this group for some reson innovation and even CAD as how used in industrie is simply not understood ; some people here rather turn a discussion into a personal harasment pointing to "their" favorite designer omitting the progress in digital projecting and how boatbuilding as a craft taken all these new technologies into count --- if you know that a CAD program carry everything from Archimedes to Pascal and know that a CAD program is just the calculations and tools alway's used by boatbuilders and designers, then you also know how silli but also how dirty the discussions in this fora work ; Now you ask and I point you to the last boat I build, you se I alway's combined tradisional craftmanship with modern tools, so what you se is _not_ an old fasion boat acturly everything is made with computer --- that is the design that is an altered Lofoten dinghie, the plans the calculations, just everything is made with computers, --- except building the boat from the ready cut planks, now tell me if I can build a boat, and tell me if you think I can design one. And if you think so please ask the other crowd to show somthing of the same quality ; ---- Please check the Foto's section to se the build boat ; http://groups.yahoo.com/group/Cyber-...foten-dinghie/ Please check the other Cyber-Boat groups to se those build boats. Per Corell |
#16
![]() |
|||
|
|||
![]()
After recent Tsunami disaster, toying with the idea to
help make hand /sail/outboard moter powered fiberglass fishing boats of standard 30 feet length. Some FAO documents on the subject: http://www.fao.org/documents/show_cd.../W7260E/W7260E 00.HTM http://www.fao.org/DOCREP/003/T0530E/T0530E00.HTM http://www.fao.org/DOCREP/003/V9468E/V9468E00.HTM Paolo |
#17
![]() |
|||
|
|||
![]()
Hi
I must agrea that I do not belive that glasfiber and resin is the only solution. I love to use Epoxies and know that a glasfiber boat offer the top of what boatbuilding achived but I do belive more in other methods and I think that sheet materials is a better alternative even as ready made sheet materials cut after Digital projecting, --- . Still I do belive that a combine of methods, like how you already se bigger glasfiber paneled boats build with wooden frames , but why not take it a step further so the boat only cost a third and is four times as strong, and the builders start using actural digital tools not rewritten old methods. Personaly I find epoxies and polyester to valuable a source and the need for digital manufactoring more important , even in space industrie the best would be metal not epoxy, but anyway if this is about efficiency what\s wrong with pre hardened glasfiber sheets pre. cut to form the framework assembly ready cut panels , and then build up inside that, ---- premade glasfiber sheets already offer one smooth side, why spend the time making an expensive plug to make a form if a new technology offer a much more promising aproach. Why not focus on sheet materials as that cover plastic aswell as metal and steel or plywood. Digital options as we se them today, is rather about making an expensive plug with an expensive 3D router just to support a maby worn out technike ,rather than using and expanding the real digital options. With 3D-Honeycomb my attitude is, that now you have the full freedom forming and a garentie for the strength , but it also is a compleat other world, than just doing what else could be made by hand anyway, realy you don\t use a 3D router for that and it seem that a simple 2D N.C. cutter prove much more efficient forming the pieces for an assembly. Today\s design and architect programs are not about shaping the form and generating the assembly but make a neat account, an account just as 70 years ago , now if we aks new solutions and new jobs it is my belive that this ask a change in perception . We still translate the old methods into computer code and ask a 3D router to router out the plug to make the form so we stay with boatbuilding as how that is today, maby a change in the way to build a boat or a house is what will bring the jobs and the nice boats and houses at a third the cost four times as strong as that ask digital tools. P.C. |
#18
![]() |
|||
|
|||
![]()
Proposal is for new techniques. Fishermen may not imbibe new ways of
boat construction without training. |
#20
![]() |
|||
|
|||
![]()
Narasimham wrote:
Am mechanical engineer with a composites background presently residing in south India. After recent Tsunami disaster, toying with the idea to help make hand /sail/outboard moter powered fiberglass fishing boats of standard 30 feet length. Raw materials .. chopped strand mat, fiberglass cloth, polyester resin and rigid PU foam are commercially available locally, as is semi-skilled labour who could make boats to pre designed drawings. I think you first have to define the boat and it's mission a bit better - hand (paddle/oar) powered will have to be smaller than sail or outboard power. How much cargo (fish) will it carry? How fast does it need to go? Rigid PU foam is o.k. for insulation and flotation but not structural purposes; it is too brittle and weak. Can someone help to guide in the following ? Shapes: Are drawings available on net? or on payment? What hull shape is better? U? Flatbottom? Hull shape will depend on whether it will be a planing boat (fast with outboard power) or slow (sail or human powered) If you hire a naval architect they will define the shape of the hull and the construction method. If you are building more than a few boats, a female mould (concave shape) is the only way to build efficiently. You may also be able to purchase stock (premade) plans from a plan company. Do Lloyds or other certifying agencies based in Europe/US have a branch or mechanism to test and certify marine craft after fabrication and testing when involved right from beginning stages in India? Yes, Lloyds, DNV (Det Norske Veritas) and ABS (American Bureau of Shipping) are the big ones. But for a third world project they will be costly and probably not worthwhile or needed. If existing wooden hull shapes are duplicated but replaced by solid fiberglass laminate or polyurethene foam (closed cell to keep out water) sandwich, would it serve the purpose with stability resisting wave forces with adequate margin before capsizing? It depends on what the existing shapes are and how heavy they are built and where the weights are located - too complex to give a simple answer here. For a physics picture of stability: 1) Is metacentric height a parameter to assess stability? Yes - higher GM means higher static stability 2) Draft. On what factors is load-depth of immersion relations established? The shape of the waterplane area (cross section of the hull) determines how much it will sink at a given draft. One thought - in Mexico fisherman changed their style of fishing boat over the past 20 years or so. Initally they used dugout canoes with paddles or simple oars and stayed close to shore. Later dugouts had small outboards added, and were sometimes replicated in fiberglass. Then the "panga" appeared, a very shallow deadrise (shallow V shape hull) about 24-26' long. It is built in fiberglass and typically uses a 48,55, or 70 HP outboard motor. These boats are very seaworthy and often venture offshore about 50 miles, catching up to about 1 tonne of fish before returning home at slower speeds. Gill nets are the most used fishing gear. These boats are beached at the end of the day or anchored just off the beach. They are built in solid fiberglass with some wood for rubrails and seats etc. They look like this: http://www.panga.com/pangagallery/pangamex.html I think they are a good solution to Mexican fisherman's needs but the government had to offer low interest loans to allow the fisherman to buy the motor and boat. Good luck. Evan Gatehouse |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
rec.boats.paddle sea kayaking FAQ | General | |||
rec.boats.paddle sea kayaking FAQ | General | |||
rec.boats.paddle sea kayaking FAQ | General | |||
rec.boats.paddle sea kayaking FAQ | General | |||
rec.boats.paddle sea kayaking FAQ | General |