22m cruising cat design concept

Discussion in 'Multihulls' started by Becaris, Aug 3, 2008.

  1. Alik
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    Alik Senior Member

    Becaris, You see - simple boat operation question and You have no clear answer. For Your info, to feed motors from gensets direct will requre gensets of hundreds of kilowats (because this cat needs about 2x(100...150)HP for reliable propulsion)! This is possible, but we are not talking about fuel saving, weight saving and cost saving technologies anymore.

    Unfortunately we have to deal with 'boatdreamers' with their futuristic-unrealistic concepts almost every day :) 'Electrical propulsion' is my favourite subject to argue.
     
  2. Alik
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    Alik Senior Member

    If You have been inside those cats, You would be surprised how small is the volume of saloon. Actually 50-footer with saloon of 35-footer... Also the headroom - 1.90m at the entrance point only, becoming 1.70m at galley and 1.50m at the stairways from saloon to the hulls.
     
  3. Becaris
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    Becaris Junior Member

    I'm not here to defend Schionning. I'm only trying to decide if there is a way to get aerodynamic shape and keep the cab from heating up due to direct sunlight. You just seem bent on attacking things, now you are having a go at Schionning. Jeez.

    As for your contention that you cannot build an electric powered cat, many 40' models are on the water and 60' models are currently under construction. Based on these actual yachts, I see no reason to change my mind on building an electric powered cat, particularly a couple years from now (though they are already being built now).
     
  4. Alik
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    Alik Senior Member

    I am not attacking Shionning's cats or anything else, just telling what I have studied from experience.

    OK, 40' is Lagoon - pls read the specs first. They can run 3 hours at 6 kts (calm water, no wind!). It will probably work for charter in Caribbean, but hardly enough for seagoing boat capable to withstand severe conditions.

    Moreover, I have designed electrical powered boat also (8m, narrow hull), but that one was for the lake. For the sea, nothing is more reliable than marine diesel.
     
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  5. Becaris
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    Becaris Junior Member

    I don't actually disagree with your numbers on current electric powered yachts, but with the BILLIONS being spent on improving battery technology, with hundreds of companies competing to get there first, there is no doubt in my mind that in short order we will have a lot more power storage possible. You may not believe that will happen in that time, but I do and neither one of us knows for sure. I will continue with my concept of using electric power, it's my money and time, and I never count out new technology when this much money is at stake. If they were developing this for the yacht industry, I might agree with you, but not when car industries and fossil fuel companies are funding this research. So let's put this discussion to rest. You believe what you want, I will believe what I want.
    I've made millions being a 'dreamer' and will never stop pushing the envelope with new concepts and ideas. As for the current 'concept' version model of this cat that I've posted, no doubt this is going to go through MAJOR changes before ever getting near a build. Just take a look at the early shots compared to the more recent ones. Night and day, and yet I know the concept will still go through more radical changes. This includes ALL systems as I will adapt to what is actually available as the time to build gets closer. Even then the concept will then go to a professional designer and engineer (neither of which I've ever claimed to be). It's just a concept to play with ideas at this point.
     
  6. Alik
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    Alik Senior Member

    Good luck!
     
  7. Spiv
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    Spiv Ancient Mariner

    Becaris,
    we are continents apart, but we want the same thing.
    I like your approach, 32 years ago I decided that one day I'd go round the world on my owh sailing boat. That boat was going to be a ferro cement monohull ketch! That is all I thought I'd ever be able to afford.
    Time pass, things change, one learns.
    10y ago I put for sale my last charter power cat with the intention to build a charter sailing cat, learn as much as possible about sailing cats, sell that and build my new home afloat.
    This last boat was a 12.5m round shaped, slanted, aerodynamic looking boat, but I redisegned the superstructure to obtain more habitable space and less sun in the cabin. Pic attached.
    I took that boat 3 times from Perth to Broome, 1600NM each way, treacherous coast the WA coast! Once got dismasted, fortunately the Carbon mast survived with little damage. But enough of my story.

    I too am designing my new boat, but I am nearly finished, my critical points are:
    1. As big as I believe I can handle on my own,
    2. space for two 90% of the time, for 6 10% of the time,
    3. as little rigging as possible,
    4. self sufficent
    5. Ability to go under low bridges, up shallow creeks and dry out,
    6. at anchor 90% of time, under sail the rest of the time (motoring only when necessary)
    7. redundancy on all systems
    8. safety: 1st
    9. comfor: 2nd
    10. speed: 3rd
    11. cost: 4th
    12. what other think of it: unimportant
    In answer to #1&2 above I ended up with the internal habitable volume of a 14m cat, but for 8, 9 & 10, I stretched the hulls to 17m.

    For #3: three furling sails, two self tacking and a traditional reacher

    For #4: solar, wind energy, heating/ cooling, diesel genset(s)

    For #5: lowerable mast, daggerboard and retractable rudders, beaching mini-mini keels.

    For #6: big anchors :D, efficient, easy to reduce or increase sails, electric motors ?? (still looking here as i want the equivalent of 2x40~50HP)

    For #7: I'll have two of everything + contingency plans/ backups.

    For #8, 9 & 10: I asked an experienced cat designer to design 17m long slender hulls with 1.1m bridgedeck clearance.

    For #11: I am working harder :rolleyes::rolleyes:

    For #12: not loosing any sleep :p

    I'd be happy to share with you any of my thoughts, if you ask.
    I am very interested in learning more about diesel electric hybrid; I have read all I could find on the web + there are a few threads on this forum on the subject. Some very interested people and some skeptics.
    I'd like to hear from you what you found on the subject.
     
  8. Becaris
    Joined: Aug 2008
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    Becaris Junior Member

    We're not as far apart as you might think. Here is your list and mine compared:

    1. As big as I believe I can handle on my own
    A: Same, accept said, 'must be able to sail by myself, though that's not likely.'
    2. space for two 90% of the time, for 6 10% of the time.
    A: Space for four 90% of the time, for 8 10% of the time.
    3. as little rigging as possible.
    A: same
    4. self sufficient
    A: same
    5. Ability to go under low bridges, up shallow creeks and dry out.
    A: same, though my yacht (for passenger average reasons) will be larger and therefore I'm not going up quite as small a creek :)
    6. at anchor 90% of time, under sail the rest of the time (motoring only when necessary)
    A: at anchor 60% of time, under sail the rest of the time (motoring only when necessary) I'm planning on doing a lot of travel.
    7. redundancy on all systems
    A: same
    8. safety: 1st
    A: same
    9. comfor: 2nd
    A: same
    10. speed: 3rd
    A: same
    11. cost: 4th
    A: same
    12. what other think of it: unimportant
    A: same

    As for diesel electric, regardless of the nay sayers, there is a lot to be excited about in going with electric propulsion. First off, comparing just horse power is not the best measurement. Torque is of much more interest. There is a lot of interesting information on that (and running larger props than diesels etc.).

    Another feature of going electric that I like is that my fuel station is wherever I currently am, moving or not. With sailing (motor sailing), solar and (boat stationary) wind power generation on board, it's a rare time that I won't be able to replenish 'fuel' (batteries). I can run out of power, but I can refuel just about anywhere anytime. Run out of diesel away from a fuel station and I doubt you have a refinery on board. There is also just the noise and smell improvements. I'd post some links to info on electric propulsion, but you have probably found the same ones (just google electric yacht propulsion).

    On a different subject, one of the reasons I'm looking into a biplane rig is so that I can design a system to lower the masts so I can go up rivers and get under bridges. With a 20m length, a single mast was pretty large and heavy to deal with, but by going with a bi-plane, each mast becomes smaller for me to deal with. There are still issues with this, but I'm in contact with some carbon fiber mast makers and they are surprisingly light to handle when kept to a reasonable length.

    My issues to deal with are that I want power rotating masts, and I also want to be able to lower them myself. It's an interesting design challenge. There are other reasons I'm leaning toward a bi-plane rig as well. Redundant masts isn't a bad thing from a safety aspect. Mounting the masts in the hulls works out well for layout and strength. And no stays or cables since there is no jib. Just two power rotating masts with self furling booms. I should be able to reef and trim the sails without dealing with ropes and winches, or going out on deck with the weather up. Of course, I'll pay for those luxuries in other areas, but I can live with the small drawbacks.

    I'd love to hear your, or anyone else's suggestions on how to achieve some of these goals. I'm also interested in your project and progress and would love to hear more as you move forward.
     
  9. Alik
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    Alik Senior Member

    Nonsence!

    ... in advertisement booklets and publications.
     
  10. apex1

    apex1 Guest

    Becaris
    do´nt believe everything you read, do it like me, believe what you know!
    And search for the Nigel Calser articles on hybrid propulsion in "Professional Boatbuilder" that brightens your view. If you cannot find them, I will post them on Monday. Or become a professional boatbuilder then you do´nt need to read them.
     
  11. Alik
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    Alik Senior Member

  12. apex1

    apex1 Guest

    Thank you Alik, saves me looking it up. I´m delivering a boat, well shakedown run to tell the truth. Every second hr another sh.t. Every second hr another mail conversation and argueing. Ahhhhh boatbuilding is fun..
     
  13. Alik
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    Alik Senior Member

    Good luck, and post some photos!
     
  14. Becaris
    Joined: Aug 2008
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    Becaris Junior Member

    It’s sometimes amazing how one person reads an article and sees one thing due to their preconceived ideas, and then someone else reads the same article and sees something different. I read your article (with my own preconceived ideas) and find nothing that deters me from considering a hybrid electrical propulsion system.

    First off, you pointed to his conclusion on page 150. Let’s be clear, his conclusion states that the author had intended to purchase, and I quote, ‘a full-dress serial system’. This is what he is comparing to diesel engine technology in his conclusion. At the beginning of his article he defines this as different from a hybrid electrical system. A serial system (according to the author) runs off a generator all the time, where the hybrid runs off of the batteries. His contention is that with current battery technology (in 2007 when this article was written) a hybrid system does not have efficient enough batteries. There is too much weight to have enough power storage. This is why he was looking at a serial system. He also states in this article, and I quote,

    “After years of being promised radical changes in battery technology, we may be on the verge of a revolution that will change the rules for designing DC systems for boats”.

    Given that two years later we do have better batteries that store more energy at less weight than when he wrote this article (lithium for one), and even more interesting battery technology on the horizon, a hybrid electrical system is becoming increasingly attractive (and this author does not disagree).

    He notes, and I quote,

    “There is an obvious trade-off here between battery size, weight, expense, and available propulsion time. Even a fairly limited battery capacity provides instant propulsion power (helpful in an emergency), plus the ability to conduct brief maneuvers without cranking an engine.”

    Coupled with the better battery technology now available, these trade-offs are tilting more and more in favor of hybrid electrical propulsion.
    Even two years ago when he wrote this article, he noted that, and again I quote,

    “On boats that sail enough to regenerate a considerable part of the energy needed for propulsion, regeneration is clearly attractive.”

    I will be one of those usage patterns, and therefore, electric propulsion is very attractive.

    This article definitely keeps my interest in the electric propulsion system, thanks for pointing it out. As I’ve stated all along, and backed up by this author, with more efficient lighter batteries (which already exist since this was written) a hybrid electrical propulsion system becomes quite attractive with lots of nice advantages. The author goes into some of these, including, and again I quote,

    “Electric motors develop full torque at any speed, down to 0 rpm. In conventional (diesel engine) propulsion installations, the idle speed of the engine will be between 700 rpm and 1,000 rpm.”

    Thus you now understand my comment in an earlier post about torque. With a hybrid electrical system I will use larger props than a diesel engine installation because I have use of torque at low rpms, and can therefore move more water without having to turn a smaller prop at higher speeds. This is backed up by the author in the article you quoted.

    In conclusion, based on this article and lighter weight battery storage, hybrid electrical propulsion is getting more and more attractive.
     

  15. Alik
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    Alik Senior Member

    Ok, quote it in full:
    'But this is not the usage pattern of most of recreational boats
    ...
    has restricted regenetative propulsion to a small niche market'.

    Nonsence #2, get the basics before we can discuss it.
     
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