Aluminium boat out of one piece - self casted, one big mold...

Discussion in 'Boat Design' started by congoriver, Jun 23, 2010.

  1. TeddyDiver
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    TeddyDiver Gollywobbler

    Then next question. Is it possible the cargos (at least a major part) going only down stream? If this is posssible they could use quite simple vessels that could be sold for building materials in the same sites as their cargos.
  2. mental_boy
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    mental_boy Junior Member

    Ok, so a bunch of questions:

    1. What kind of loads are you interested in carrying?

    2. What are the conditions of the route? i.e. depth, current, protected/unprotected, minimum channel width, etc?

    3. How much money is available for construction and operation of the vessel? And how much can be charged for transporting the goods, to pay for fuel?

    4. How fast do you need to go? e.g. if the boat carries perishables it may be desirable to go faster, although going slower saves fuel and requires less hp. Fuel savings can be dramatic at low speeds.

    5. Maximum width of the vessel?

    6. If the vessel is to be made of wood, then what types of wood are available and are they free to cut? The fao document states it is desirable to use low density wood for planking and high density wood for framing.

    7. If steel is a possibility, then what is the cost and availability of steel plate in the area?

    I wouldn't underestimate steel as an option. It may sound daunting if you are unfamiliar, but it is easy and forgiving to work with and tooling cost is modest.
  3. mental_boy
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    mental_boy Junior Member

    Also, out of curiosity, what kind of plants are you farming and how much carbon do they consume?
  4. apex1

    apex1 Guest

    The largest of them (which could be scaled up to some extend) carries more per $ spent on building it, than 3 or 5 or even 7 of the boats you have at present. The easily available Listeroids (when I remember right, but you did not comment on that) consume catpinkle if there is a drop of oily substance in. They cost nearly nothing, run forever, and propel the largest FAO boat up to 8kn.
    If thats NOT a starting point, where do we start then? Nuclear propulsion?

    I guess Sam Sam is not too far from reality with his doubts!

  5. hoytedow
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    hoytedow Carbon Based Life Form

    Excellent point.
  6. congoriver
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    congoriver Junior Member

    Mmm, interesting idea. But I think it should be a boat that can be used to go upstream too. There's a demand for simple goods in the villages upstream (sugar, soap, plastic utensils, etc...).

    But it might be interesting to run a few scenarios and to study the costs/profits of a boat that would be disassembled when arriving in Kinshasa.
  7. congoriver
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    congoriver Junior Member

    Thanks for the questions, I'll try to answer them crudely.

    -Downstream, from the villages to the cities: agricultural products like bags of maize, maize flour, cassava flour, chikwangues, smoked fish, bushmeat, and perhaps rice and beans.

    -Upstream, from the big cities (Kinshasa, Mbandaka): consumables (canned tomato paste, salt, sugar) and household products (soap, plastic items, pencils, possibly clothes and shoes).

    We're talking about the Congo River and its main tributaries. 15,000km of navigable rivers/ They're navigeable year-round, even though there is a problem of shifting sand banks here and there, mainly during the dry season.

    The river is often several kilometers wide, and a good navigator can easily avoid sand banks. The current: I'm not sure.

    Let's take the Lisala to Kinshasa route as the reference point for our discussion:

    -Distance: +/- 1300km
    -Width of the channel: on average several km, interspersed with islands (here and there the river's 20km wide)
    -Current: as said, I don't know, but it might be a smooth 5 to 10 km/h

    The money that we can invest is limited, but we have some people who would step into this thing if we can demonstrate that we have a working plan that results in commercially viable boats that can be replicated.

    For a first vessel, say a "demonstration vessel", we can spend only US$10,000 for the hull. (I'm only talking about the hull, the rest should be kept low-cost too).

    -Current rates for boat trips on the Lisala-Kinshasa trajectory (this is on the big commercial boats, of which there are only a few): 5000FC for a 100kg bag of maize that's 50,000FC per ton/54US$ per ton; these prices fluctuate heavily, depending on prices in Kinshasa (the captain knows that if prices are high in Kinshasa, he can charge higher as well). Then you have to add administration costs, which are around 2000FC per bag (say US$2), so that's another US$20 per ton. Total: US$ 70 per ton.

    Other products all hover around the same price, even though some are almost free, like charcoal (bulky but light-weight), often carried by women who transport just a few bags of maize - the captain then allows these women to carry some stuff for free.

    Remember, the main boats currently in operation are floating villages. Not everything is priced there.

    On other items, such as rare fridges or gensets, the captain will empty your pocket, because he knows that you really want to get that item transported, and because he knows that a person with a fridge is very wealthy.

    If we have a 10 ton boat full of maize, we would only make US$700 in revenues - from which we'd have to extract fuel costs, administration costs, and personnel costs.

    We should make a boat that can also carry people, because otherwise we won't find clients. People want to travel with their cargo. The average price per body, for the Lisala-Kinshasa trip is 30,000FC (US$32).

    This is roughly what I know concerning prices.

    The trip upstream in the floating villages takes on average (depending on the season), 3 to 4 weeks. This can be more, depending on where the boat stops and unloads along the way. Our 2 boat trips took 4 weeks each.

    The trip downstream takes much less, around 10 to 14 days.

    Mind you, the floating villages will sometimes take weeks to fill up. The captain/business owner decides when it's time to go, quite arbitrarily for small clients. But he decides to wait, sometimes, because perhaps he has a big contract to transport Jeeps. And so all the little people have to wait for the Jeeps. There have been occasions that villagers upstream haven't seen a cargo boat in months.

    In short, I don't think speed is that much of an issue. We should do equal or better than the current boats. We can greatly improve on loading/unloading times and decisions - that's the key - because we would never carry large or special items like cars or industrial machines. Our business would be agricultural products and household items.

    I'm not an expert, so I have no idea on that design aspect.

    The floating villages are several big steel barges that are tied together. They're often 2 to 3 barges wide (say 15 to 30 meters) and 3 to 4 barges long (40 to 60 meters). They're pushed by a big tug/barge.

    Wood resources - of both types - should not be a real problem. There's a lot of it left everywhere along the river. However, transporting the wood to a construction site may be a problem.

    In Kinshasa, steel is plentiful, all types.

    -sheet/plate sizes are uniform across all thicknesses: 1 meter x 2 meters.

    -2mm costs: US$80 per sheet
    -3mm costs: US$200 per sheet
    -4mm costs: US$300 to 400 per sheet

    The guy can weld, he's a boat builder, and he still has some relations with the ONATRA, where he can use the (by now defunct) boat building infrastructures (like dry-docks).

    When I told him I'd be interested in building boats, he told me it's a "piece of cake" to work in steel, even though he contradicted himself afterwards by telling me a story about how he once made a barge for a general and how he got complimented because the task is so difficult.

    So I'm not really sure, but he knows how to do it. The question is: can an ordinary welder/steel cutter/metal worker, of moderate intelligence, do it, on the basis of a plan, after having been initiated by our man (or a similar guy)?

    Replication is key. The boat should be designed in such a way that we can make several of it, rapidly, and at a low cost, by local, skilled people, who are, however, simple welders/metal workers, etc....

    EDIT: note that if we were to build the boat in wood, it can be constructed upstream, in small towns or villages, because the raw material is locally available (apart from tools). If we were to build in steel, that would only be possible in Kinshasa (downstream, the capital), because otherwise steel plate prices would be prohibitive (prices in Lisala are double/triple those of Kinshasa - if at all you find them in Lisala, which I doubt).
  8. congoriver
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    congoriver Junior Member

    We're doing a biochar project.

    My organisation:
  9. apex1

    apex1 Guest

    Build in wood!

    W O O D.

    Build according to the Amazon river boats where the situation is almost the same.

  10. aranda1984
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    aranda1984 aranda1984

    I like the picture, where the three small boats (canoes?) are tied together...

    Build on that principle.

    Take a catamaran or triamaran idea, using two or three of those abandoned boats and secure them with at least two, strong, but light cross beams.

    How to make them safe and 100% sea worthy? ...

    Make a rigid cover for each floating hull and fill the cavities with a closed cell, two part expanding rigid foam. This way the hulls can never be filled with water, they will always float as long as they are tied to the structure!

    Now make a decent and light deck in the middle of this craft and you may even add a canvas roof.

    You will probably get away with one engine. You can use a small sail also.

    Now this is only an idea for a small farm to get the goods to the market, but you have to start somewhere.

    The possibilities are limitless, and the wessel can be an incredibly light structure if you keeep engineering principles in mind as you make the deck etc...
    Depending on the load, you may have only inches of draft... for shallow waters.

    You may row, paddle or use pedal power if the hulls are slim and the overall displacement is light! (Especially downstream!!!)
    Last edited: Jun 25, 2010
  11. apex1

    apex1 Guest

    at least on one point.

    ...especially downstream. I am sure he did not know that.
  12. NoEyeDeer
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    NoEyeDeer Senior Member

    What you are forgetting is that a/ this will leave no space for cargo in the hulls and b/ the weight of the foam will actually reduce the cargo carrying capacity and c/ that much foam is not cheap and d/ it will likely cause rot or rust (depending on what the hulls are made of).

    The problem is that this guy is talking about shipping cargo hundreds of kilometres. For this purpose it is better to have one big boat then twenty little ones. More economical that way.

    Not really. Not for what the OP wants to do. I remember reading about programs in Bangladesh that were aimed at improving the sailing ability of the traditional river boats. The programs were well intentioned but impractical. The locals found their own solution. They ignored the advice given to them and got themselves some cheap Chinese diesels and converted their boats to power. This enabled them to actually ship decent amounts of cargo where they wanted it and when they wanted it. :)
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  13. NoEyeDeer
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    NoEyeDeer Senior Member

    Oh, just thought of something which is kind of off topic (excuse me) but may be worth considering. If the OP is also involved in carbon sequestration anyway, and if (as seems likely) the proposed cargo vessels will be diesel powered, it may be worth looking into expanding the sequestration project to also include production of biodiesel from local crops.

    If that was practical (and you'd have to crunch the numbers) it could end up being very useful for all involved.
  14. apex1

    apex1 Guest




  15. Ilan Voyager
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    Ilan Voyager Senior Member

    River transportation is a very old mean of transportation and there are numerous traditional solutions. It's efficient if you do not search speed: a 300 tons barge uses a 80 HP diesel engine...

    There are traditional cargo boats made in wood using sails and now also engines. The design is pretty old and works since more than 3000 years. These boats carry stones, wheat, cattle, fruits and even armies long time ago. You can see them on the Nile in Egypt...
    The faluka in arab, feloucca in english.

    I've sailed on one, not a "yacht" version for tourists but a true cargo with 20 tons of wheat. Not fast but steady. That works, and well!

    Like Richard, I scream: Build in wood!!!!!!

    I do not know how are the winds on the Congo River. But I think that a felucca-like boat with a diesel engine like the Indian listeroids (these things are indestructible and can run on mix of vegetable oil and diesel) or chinese Changfa engines gives a first idea. Or simply a small truck engine. I saw a shrimp fishing boat in Senegal using a complete truck engine with clutch and gear box, and even using the truck hydraulic steering system.

    Another path for very simple wood boat building is the V bottomed boat with transverse simple or double planking. That uses short planks, and short planks are the cheapest. Look at the North Carolina heavy cargo sail boats of the end of XIX century and Draketails for a "fast" light river boat.

    Wood can be protected simply with oil and a pigment: the cheapest being iron oxide red, yellow or black (3 US$/Kg in Mexico, a kg tints 10 liters of oil, iron oxides are used for tinting cement) in suspension in the oil. Any oil that dries naturally without siccative works; soya, linseed, nem, tung and surely many others (maybe palm oil, I would try peanut oil). Some oils are toxic for insects and rot fungi.

    Tar or even soot helps also in the bilges. On river or lakes, a wood treated with ordinary salt, and coated with oil and wax will last. The rot fungi and the insects do not stand salt and other minerals. Do not use chemical organic compounds; expensive, highly toxic and short lived.

    Stronger alternatives of very low toxicity for mammals, used in aqueous solutions for aspersion or dipping:

    Copper oxychloride, it's a very common fungicide used on crops, and the great advantage is that 1 kg of Copper oxychloride contains almost 500 gr. of copper metal. That gives about 200 liters of aqueous dispersion for wood treatment. Cost: 10 US$/Kg. in Mexico. Con: may react with the galvanization. Stains in green.

    Borate salts are very efficient, and expensively sold in the States under the brand Timbor. The cheap alternative; Foliarel, an italian fertilizer for strawberries, composed of 99.8% of sodium octoborate. Used also for making glass. Price 2.20 US$/Kg. in Mexico. 1 kg you gives 5 liters of aqueous solution, for very deep treatment of 10 sq. meters. A that concentration, even the Formosan termites do no approach the wood. Great pro of the borates: none reaction with steel and galvanization.

    The oil/paraffin or carnauba (there are several vegetal waxes) treatment delays the leaching of the salts in the water.

    Wooden boats die by the nails and fasteners. The very first thing to make is a small zinc hot dipping shop for the nails and small items. The tooling is very simple; a steel pot, sulfuric or hydrochloric acid, ammonium chloride as flux (less than 2 US$ a kg in Mexico) and zinc. With 5 kg of zinc you can hot dip a big bunch of nails. Double hot dipped nails last more than 20 years in soft water. The local blacksmith can make the biggest nails from scrap. And it's cheaper than imported lightly galvanized nail.

    The propellers can be made in aluminum by the local foundries. Aluminum propellers are easy to make, repair and modify. Won't last like a bronze but it's dirt cheap and recyclable.

    The hydrodynamics of boats until 6 knots is very simple, and the power required for a 5 knots boat of 40 feet on flat water is very small. A simple boxy shape with a good bow will work. Another idea is to design a boat able to beach so it can stop at every village.

    Just some ideas thrown on the paper. Think about.
    Stay simple and low tech, using local materials and local craftsmanship. Steel looks nice, but needs tooling, welding (and a lot of electricity), specialized workers, imported steel and imported paints, things very expensive in Africa. Until 15-18 meters classic wood is unbeatable on small third world river and sea fishing boats

    A wooden boat can be made everywhere with local woods, hot dipped nails and basic tooling. It will need maintenance, but with very cheap materials: oil, tar, paraffin or wax and salt. Wood lasts if properly sawn, salt treated and dried (the most important step). Traditional wooden boats are very easy to repair. And it's dirt cheap compared to imported metal or polyester. And gives work for the local people; the money stay in the villages, not in the pocket of the rich importer.

    I almost forgot; have a look on the Bengali river boats as said someone in this thread. The FAO publications are a gold mine. There are also very interesting boats on the Mekong river.
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