Cruising Cat Width

Discussion in 'Boat Design' started by Inquisitor, Nov 1, 2005.

  1. JonathanCole
    Joined: May 2005
    Posts: 446
    Likes: 10, Points: 18, Legacy Rep: 58
    Location: Hawaii

    JonathanCole imagineer

    Why do say that weight is not important?

    I don't want steel because of its corrosion problems. I know you can coat it and it will last if you are meticulous about maintenance. I don't like crawling in small spaces to check for corrosion.

    I am considering stressed plywood and laminated frame pieces for the cabin. Plywood and epoxy might be worth considering for hulls (that's how I made my first houseboat back in the 70's), but once its punctured the water seeps through the wood.

    Polyester resin is not as tough as epoxy but still not a bad choice. Although I prefer using it as a fairing material. Also glass reinforced polyester tends to be brittle and breaks with jagged edges. Not that I intend to break my boat, but s**t happens!
     

    Attached Files:

  2. masrapido
    Joined: May 2005
    Posts: 263
    Likes: 35, Points: 28, Legacy Rep: 330
    Location: Chile

    masrapido Junior forever

    without a desire to sound like a resident salesman,, 93% efficient brushless DC motors here would cost you +/-$20 000 000 chilean pesos, divide that by 630 and will get roughly us dollars.
     
  3. yipster
    Joined: Oct 2002
    Posts: 3,486
    Likes: 96, Points: 58, Legacy Rep: 1148
    Location: netherlands

    yipster designer

    i said "that important" as in "not that much important". some more or less weight is not so critical on a say 15.000 kg slow displacement boat as power needed to bring a 16m boat at a hullspeed of 18 km is only 100 hp, a displacement cat may do a little better. optimising wsa and cost i figure more important than saving weight by using exotic materials here, just as it is with the solar cell technology discussed. than again, it takes 746 watts to develop one horsepower. was talking to a frend who operated solar panels for years and was very pleased with them till they got stolen.

    edit: oops, has not gone through the calcs but think only half that hp is needed.
    do agree with stewi below but have my doubts over the importance of weight here
     
  4. stewi
    Joined: Sep 2005
    Posts: 60
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Atlanta,GA

    stewi Junior Member

    A heavier boat requires more power, regardless if you accelerate or keep it in speed.
    I think for your perspective trip, plywood is the better choice.
    There are too many steel objects, bollards, locks and strong holds in rivers and canals, which could create electrolyses on an aluminum hull.
    You should also keep the boat light, because you plan for a long cruise and have already plenty of stuff (bikes are great or even motor scooters for your land excursions).
    River and canal banks are not nice to boats (concrete or granite rocks). I guess, you will not have your rudder or prop the lowest points of your boat. A solid oak keel or skeg should protect your hull rudder and prop. If you could get your prop out of the water, like an out-boarder, it may have some advantages.
    You need to be able to stand on the side decks and get easily from one side to the other when you are in locks.
    Your bollards should be laid out, that they don’t tangle with the solar panels. All locks are pretty calm and you don’t have much water turbulences. I was always able to control the boat myself with one bow and one stern line. Kindly refuse help from bystanders. You are better off doing it yourself or with your own crew.
    All locks close to the same time, which means you’ll see who is around you. Nevertheless, keep an eye on other boats around you. They may tie their boat on yours and walk over your boat to get on land. Don’t expect that everyone knows what solar panels are. They (charter boaters) may think this is a pretty gangway.
     
  5. Inquisitor
    Joined: Nov 2005
    Posts: 276
    Likes: 11, Points: 18, Legacy Rep: 155
    Location: North Carolina Mountains

    Inquisitor BIG ENGINES: Silos today... Barn Door tomorrow!

    Brush-up

    I just have a few hours of research for electriciz-ing a cruising sailboat. Note: Not constant duty! Could someone discuss the issues with brush/brushless. Some mess, some maintenance… but
    $32,000 US for brushless…

    The brushed one I was looking was 89% efficient for 9HP for $500.
     
  6. stewi
    Joined: Sep 2005
    Posts: 60
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Atlanta,GA

    stewi Junior Member

    The main price and efficiency difference of brush type or brush-less motors is how you create the magnetic field of the rotor or stator. If you use rare earth magnets, than as the name says it is getting a bit exotic so is the price. I don’t know if you had these magnets once in your hand, but if you stick them to iron, you hardly get them off.
    The cheaper motors in the electric out-boarders have very likely no permanent magnet inside, but therefore the magnetic field is produced by another electromagnet. Since the electromagnet requires additional energy they are not as effective.
    Any AC motor is by its nature a brush-less motor, because the electro magnetic field rotates in a sine wave. However, this is not an expensive rare earth magnet motor. With the advancement in electronic you can mimic the sine wave of a DC source and run an AC motor from a battery.
    The small out-boarders from Walmart operate on 12 volt and will require some hefty cables
    Look here for a better choice:
    http://www.frenchmarine.com/Product.aspx?PID=237&CID=21
     
  7. yipster
    Joined: Oct 2002
    Posts: 3,486
    Likes: 96, Points: 58, Legacy Rep: 1148
    Location: netherlands

    yipster designer

    Jon, little more on weight. you probably have it all cakculated but aiming at a little lower speed of say 10 km a 10 to 30.000 kg displacement boat can do with even less than 25 hp according to Keith and Crouch, see attached spreadsheet
     

    Attached Files:

  8. Inquisitor
    Joined: Nov 2005
    Posts: 276
    Likes: 11, Points: 18, Legacy Rep: 155
    Location: North Carolina Mountains

    Inquisitor BIG ENGINES: Silos today... Barn Door tomorrow!

    Thanks yipster for the spreadsheet.

    Can I use this for something of the 40’ cruising cat variety?
    Naive question… what’s a DWL? The boating dictionary didn’t recognize it. Being “at rest” helps to confuse any of my guesses.
     
  9. D'ARTOIS
    Joined: Nov 2004
    Posts: 1,068
    Likes: 18, Points: 0, Legacy Rep: 321
    Location: The Netherlands

    D'ARTOIS Senior Member

    In France, anything over 5 mtrs Beam or 16 ft is void. Specifically the locks in the CdM (Canal du Midi)are no wider than that number.

    Don't forget that.

    Further: the price in europe for berthing goes per sq. mtr - and therefore cats are always berthed on the outside of a pier; so maybe a little negotiating with the harbourmaster might get you a somewhat cheaper rate.

    The absolute avantage of the cat in France and England is that you can dry out, something you can't do in Holland.
     
  10. D'ARTOIS
    Joined: Nov 2004
    Posts: 1,068
    Likes: 18, Points: 0, Legacy Rep: 321
    Location: The Netherlands

    D'ARTOIS Senior Member

    It's all very nice what you are discussing but according to my sources the net net powersupply of a solar panel, moderated over a period of time, is no more than 60% of it's theoretical output - that number might be a bit higher in the southern countries, but here, in Holland it is calculated on a max of 60.

    Solar panels ask for storage of energy. You need quite a bank of batteries to get a motor of some substance going. Displacing a large houseboat of say 14 ft x 60 ft requires something like 6 to 7 bhp per ton displacement, not calculated the windresistance - that most people forget to include in their calculations.

    I very much doubt that you may enter the Rhine river wiyh such a boat that is clearly underpowered for navigating this river.

    The Rhone streams with tremendous power down to the Med. You won't be capable going upstream with your electrical powered houseboat Downstream is easy, but upstream isn't.

    The Rhone runs with about 10 km/h, the currents are heavy and with insuficient power it is even dangerous.

    Stefan's observations are exact and I remember that tunnel and there are more of those.

    The "peniches" have always priority, and they care very little because they are always the winner.
    The restricted headroom is 3.20 mtrs on most of the French waterways; in the CdM it is even lower, anything above 2.30 is already a problem because of the bridges that have only this height in the middle but drop down considerably at the sides.

    The usual old fashoined canalboats of Holland and France are narrow and made out of steel.
    It would be much more easier to create a superlong "Gabare" because any length within 25 mtrs won't cause that much of a problem.
     
  11. yipster
    Joined: Oct 2002
    Posts: 3,486
    Likes: 96, Points: 58, Legacy Rep: 1148
    Location: netherlands

    yipster designer

    thanks for stepping in here Artois, was allready thinking bout under powering and with your healthy "Displacing a large houseboat of say 14 ft x 60 ft requires something like 6 to 7 bhp per ton displacement" its back at bout 100 hp. DWL is the stripes on the waterline, displacent, light to loaded right? long inland water routes i only dreamed about so far but amsterdam marseille and Canal du Midi i had programmed open for 2.70m high. can open the file on my laptop and give more details. spoke to this noordersoft guy just the other day on the europort exhibition.
     
  12. D'ARTOIS
    Joined: Nov 2004
    Posts: 1,068
    Likes: 18, Points: 0, Legacy Rep: 321
    Location: The Netherlands

    D'ARTOIS Senior Member

    In the middle, Joop, in the middle - a houseboat has mostly a square profile- are you with me...... and it is 2.60 ...... what about the waterlevel.....
     
  13. yipster
    Joined: Oct 2002
    Posts: 3,486
    Likes: 96, Points: 58, Legacy Rep: 1148
    Location: netherlands

    yipster designer

    [​IMG] [​IMG]
    hmm 2.60? have to check, waterdepht, bridges, marifoon channels, opening times (my version is "97) and a lot more, if you want i dig up the details of inland routes. even a usa inland waterways version now! its a unique program for bout € 200 with canals now a bit more detailed and also now interactive with river information services with gps and more at www.noordersoft.com

    here another solar houseboat making windage...
     

    Attached Files:

  14. D'ARTOIS
    Joined: Nov 2004
    Posts: 1,068
    Likes: 18, Points: 0, Legacy Rep: 321
    Location: The Netherlands

    D'ARTOIS Senior Member

    I have travelled the CdM Joop, it is a marvellous trip, highly recommended but totally useless for wide and high craft. Have you seen the bridges at Sète and the Grau du Roi area?

    Whe waterlevels are high, the headroom becomes lower, one advises if you travel the Rhone to limit your headroom tool 3.20 mtr. If you think logic than you know that if you design a housboat on a cat's configuration, it will be dificult to keep your ttl height under 2.70 mtr - as long as you want to keep your feet dry.
    The 2.70 mtr is as high as you can get and than I am still a bit optimistic.
    I have lived in the Camargue a whole winter chasin bulls with the guardians and just recently I have been there and nothing have changed much. So ifyou want to travel the CdM make sure that your boat fits the locks. I shall see if I can scan some pics.
     

  15. D'ARTOIS
    Joined: Nov 2004
    Posts: 1,068
    Likes: 18, Points: 0, Legacy Rep: 321
    Location: The Netherlands

    D'ARTOIS Senior Member

    Canal du Midi

    Here we go...... www.canal dumidi.com
     

    Attached Files:

Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.