The perfect Passagemaker III, propulsion

Discussion in 'Boat Design' started by apex1, Aug 26, 2010.

?

Please pick your poison

  1. Trawler: single Mitsubishi

    14 vote(s)
    35.0%
  2. Trawler: twin Luggers

    11 vote(s)
    27.5%
  3. Yacht: single Grenaa Diesel

    13 vote(s)
    32.5%
  4. Yacht: twin Mitsubishi´s

    2 vote(s)
    5.0%
  5. Yacht: twin Luggers

    4 vote(s)
    10.0%
  6. I am fine with less accommodation in favour of a large engine room.

    26 vote(s)
    65.0%
  7. I prefer large accommodation, the engine room is second.

    2 vote(s)
    5.0%
Multiple votes are allowed.
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  1. apex1

    apex1 Guest

    A very important point Mike!

    As West said, with the Grenaa Diesel this is a moot argument. But for the smaller engines we have to go electronic today to stay within regulations. Fortunately the engines developed for commercial use come with a "manual override" function, or a "emergency fall back" mode, makng it possible to run them when the electronic management is shot.
    The "fully" electronic engines would need a spare engine controller stored in a faraday cage (together with a handheld GPS).

    All engine, CPP and rudder controls are non electric/electronic and work even after complete blackout (lightning). Only the flybridge works over separate actuators.

    Having a bus system does not seduce me to include the engine room for convenience.

    I understand your worries Manie.

    In this example (the 24000ltr are related to the Grenaa), we have a engine that consumes veg. oil as well, or many other tastes of "alternative" fuel. That makes it much more feasible than any other propulsion.
    Not to step into the senseless sails discussion, but one point is always forgotten in these disputes. When fuel oil goes rocket high, the cost for a rig does also!
    Bunkering this boat is about 14.500 US$ today, that lets you cruise for about 3-6 month, given a Atlantic crossing and exploring half of the Med. Sea is your task.
    Mooring this boat in a marina with one permanent caretaker onboard is more expensive!!!

    Well said Mark.

    In fact I know several people, operating motor yachts in the south pacific region, doing exactly what you describe here.
    One runs a old Danish coaster (consumption 2,5 tonnes/day), between remote islands. He makes it for the fun of sailing, not for the lousy income.
    Another couple provides dental health care on the barefoot route.
    And one is just baking sour dough bread while charging the batteries every other day. There are many more.
    Not to count the hundreds of tows and commuter services provided every week by motor yachts all over the world, rarely receiving more than a thanks, if.

    Regards
    Richard
     
  2. pool
    Joined: Sep 2010
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    pool Junior Member

    It’s not about absolute $$$, or affordability, or personal freedom at all. Much less about a tow to your buddy or bringing antibiotics to the islands - done all that myself.

    But when you cross oceans, just put a stick and some canvas on your trawler and cut your fuel consumption to a fraction. You will not have less fun, or less of other returns along the way, but have 20.000 of those 24.000 liters left in your tank when you arrive - your grandchildren will love you so much for that !
     
  3. powerabout
    Joined: Nov 2007
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    powerabout Senior Member

    except when your dead and they have to sell your sail boat and its worth way less than you paid for it
     
  4. apex1

    apex1 Guest

    A dream mate, just a dream. Reality at sea is different.

    And STOP talking sailing NOW! thats one of the conditions here.
    You must not like them, but you will accept them.
     
  5. pool
    Joined: Sep 2010
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    pool Junior Member

    Ne nuntium necare ...

    have a great day !
     
  6. apex1

    apex1 Guest

    Was not my intention,

    just the message was wrong.:p
     
  7. Ad Hoc
    Joined: Oct 2008
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    Ad Hoc Naval Architect

    Without going over too much old ground, i would concur that hybrid is a waste of time/space and money for this vessel. Other than using solar for aux equipment etc. Certainly not for propulsion.

    I recently did a review for the university here of hybrid technology and applying it to ships. The best, and i do mean 'best' options currently available for say stored fly wheel types etc, the best one can get is 10%. Far too many losses in the system, the added weight etc and then storing the energy and when it is being used blah blah blah. Was a real eye opener when you actually plug through the equations and obtain efficiencies and the end result. Pipe dream, for now….unless you want to fly a kite:
    http://www.kiteship.com/marine.php

    As for main engine, go with what ahs been proven before and works, day in day out. Nice slow heavy diesel.
     
  8. brian eiland
    Joined: Jun 2002
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    Location: St Augustine Fl, Thailand

    brian eiland Senior Member

    Hybrids, Flywheels, Kites...

    Since you brought the subject up here I want to ask a few quick questions, then hopefully continue the discussion elsewhere its more appropriate.

    Are you saying that the flywheel energy storage method might be the more effective at this point in time?

    Then you might agree this would be a better approach:
    http://www.boatdesign.net/forums/boat-design/new-age-trawler-motorsailer-kite-assisted-poweryacht-20319.html

    The power would be a single main engine sized to develop the vessel’s desired top speed, and it could transmit this power by conventional shaft/prop arrangement, or with a azimuthing Volvo IPS dual prop unit, or via a retractable azimuthing Rim-Drive prop unit as I included on my latest dynarig motorsailer design.

    Supplementing this single main engine would be a single DC diesel/electric power unit to provide for:
    1) Ships electrical requirements
    2) Slow speed operation by electric (wing) motor belted to main prop shaft
    3) Maneuvering thrusters as required depending upon azimuth capabilities of main prop.

    The entire ship would be powered by only two engines, basically sized to provide:
    1) Full main diesel power, unimpeded by interceding diesel/electric conversion
    2) Slow speed operation and ship’s systems via the smaller diesel/electric unit
    3) ‘Twin power’ emergency backup as either engine can run all gear
    This configuration more ideally meets the latest thinking for the new diesel/electric DC technologies onboard smaller vessels. Alternatively, two identical diesel/electric plants might be sized such that in combination they would supply the max power required of the vessel, and half power for lesser times.

    Only two engines and no conventional sailing rig should make this a more affordable vessel, both in construction, in maintenance, and in operation. However the SkySail kite arrangement will probably more than offset the conventional sailing rig in cost.


    I do understand this, but aren't quite a few of these 'old stds' going to be phased out with this new emphasis on pollution stds, etc. Lets hope NOT.
     
  9. Boston

    Boston Previous Member

    I had a thought for engine room maintenance convenience

    In the boat I was designing a while back I had planned on twin engines with a chair on rails that ran in-between them
    That way I wouldn't be crawling into the engine room but instead sitting in style while I do whatever

    No point being uncomfortable when your supposed to be enjoying yourself

    B
     
  10. wardd
    Joined: Apr 2009
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    wardd Senior Member


    if you had your bed between the engines like any real man would want, you could fix them before you got up
     
  11. peter radclyffe
    Joined: Mar 2009
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    Location: europe

    peter radclyffe Senior Member

    a dentists chair with a stereo
     
  12. Boston

    Boston Previous Member

    Oh the abuse

    I was kinda thinking that a comfortable way to traverse a short room would be seated
     
  13. wardd
    Joined: Apr 2009
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    wardd Senior Member


    how about this, the engines mounted on a cradle that you could raise

    if they can change a tank engine in half an hour that could be done

    the cradle could have locating pins to relocate it
     
  14. Ad Hoc
    Joined: Oct 2008
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    Ad Hoc Naval Architect

    No, not at all. Just reviewing the current state of play, thus:

    The main problem with a fly wheel is the weight. To be effective is needs to have mass, but it cant be too big as it will add displacement tot eh boat, thus slowing it down. So it can only be a certain %’age of the overall displacement to mitigate the added displacement owing to the overall weight of the system, this immediately limits the amount it can “give”. To work properly, it’ll need to be CVT, which again adds more weight and complexity.

    Once you have “got” energy, you have to store it too…since you wish to use it when you want to use it, not just because it is suddenly available. This comes with its own set of problems.

    So to save weight use of ‘advanced’ materials, such as carbon and graphic etc. But, this does not obfuscate the obvious...it is spinning very very fast, and safety issues tend to over ride the max RPM than pure theory. (if you house it, like one must do with big GT’s on a boat, more weight!) Not to meant a near frictionless bearing, in a marine environment.

    You also have to reduce the gyroscopic forces when the vessel is underway, more complexity and weight again.

    The specific energy of a flywheel is the ratio of the energy stored to the flywheel mass. This already becomes limited by the maximum allowable stress (hence advance materials) and max rotor speed, already linked to safety issues.

    And on and on it goes….not saying it can’t be done…but as yet….just not feasible.


    The old more polluting ones are being phased out yes, but their principal raison d’etre remains. As such they are just evolving, not becoming extinct.
     

  15. Boston

    Boston Previous Member

    Actualy the most advanced flywheels are pretty light and spin at phenomenal speeds
    The issue would one of conservation of energy
    As the boat continually would redirecting the axis of rotation thus that energy would be directly subtracted from forward motion of the system just like if it were a suspension system.
     
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