Is It Cheaper To Motor Or Sail

Discussion in 'Boat Design' started by Boston, Mar 20, 2010.

  1. Boston

    Boston Previous Member

    guess not ok so in conclusion the question of motoring or sailing is dependent on the location intended

    in the case of the pacific northwest inside passage Ketchikan area it seems for me at least a power craft is the way to go

    cheers to all
    B
     
  2. tugboat

    tugboat Previous Member

    Boston- i am biased...but im torn between my love for free energy(wind) and the convenience, but for me the ease aspect of pushing a button having the engine fire up and then just going. no need to worry about rigging, or about drafts- wind, calms, etc.(powerboats usually have less draft), sailing is more eco-freindly yes and don't get me wrong i do love to sail a good tri or a cat!
    - but in certain areas..its not as practical. its more economical, but it has less space.
    In the end I also have seen a LOT of motoring done by pro sail types. you also have to realize that engine in your sailboat has a prop and the drag on that is substantial! slowing you- As you can see i have a bias towards motoring... and the bigger(forget waterline length argument here) the slower unless you spend the big bucks on good sails and special carbon masts and hulls, then your margin between running costs and initial costs is shot.

    powerboats can be bought for less initial costs depending on what you buy..but as a general rule they are cheaper.

    in fact since the hull of a motoring vessel is designed for that purpose and a sailboat is designed for sailing - guess which is more cost effective while motoring??


    and pffffff..... to whoever said motoring was boring,- hmmm guess you never drove a tug! (I have)or a submarine?..(Laugh- ok so maybe I never drove a sub yet!) but i bet a sub would be way more cool than a sailboat. anyway try motoring a boom boat they look addictive.

    thus-my opinion- the design i saw you post was very nice for a cruising motor hull- its not a sailing design..so plop in that ford. (dont walk- run from the sailmaker if you can find a good cheap one)...install the proper gearing- reverse- reduction and then away you go..use the right motor and prop and youll be sipping fuel...especially since your design as posted, to me , is wayyy cool..and should be easily driven at lower rpms. you dont need to go fast since most sailboats could not make a passage as fast as a boat running 24/7 at 20 knots or cunard would have sailed the titanic! even at 5 knots the powerboat has the advantage. due to differing wind conditions etc.

    of course if the wind was substantial the sailboat owner would reef the main and have to ride out the gales. using ***-ache techniques to slow them while running or not to broach and have them turtle or pitchpole. using complicated self steering systems if they want that coffeer break..and not in shiping lanes!

    if you sail--youll have to figure out many other things on your motoring hull.--like stability, point of center of effort(not easily found), and a myriad of other things..

    wouldnt you rather be enjoying a whale watch instead of trying to figure out how to reef your sail while you are sailing and drifting in a five knot current with a cross sea, so that now you have to avoid rocks and must go start your engine anyway cuz maybe your course is a little off since your boat is not a real sailboat! and if it is..your now in big trouble if that old volvo engine you got a deal on got wet from the spray wont start and your about to collide with a deadhead,
    while all this is going on and you are trying to save your ***- you are missing the whales while you start your sailboat motor which you would be using anyway if you had gone with a motor type boat in the first place!?
    on a powerboat generally you are drier more comfortable, you can eat, drink and be merry while the boat is moving- well at least your crew can...
    compared to the heaving and rolling and heeling a sailboat does, and the possible hiking out they might have to do constantly...for a powerboat you can just put the boat into neutral for a few mins while you go take a pee if its really heavy weather! something you cant on a sailboat ..lest you heave-to- lower sails etc etc, even change sails perhaps..doing the little "latrine dance" all the while- and because you draft less (even multihulls have a big centerboards or daggerboards which are big on draft) you can sneak into coves sailboats just cant go into(heavily ballasted sailboats are almost half submarines anyway)...btw dont hit a reef with a full keeld sailboat..not good!
    ok not good for any boat but better with the powerboats skeg.

    azllthis is just my humble bias...i mean no offense to real sailors. i still love sailing. just in my old and gnarly and arthritic and back-broken years, i find i am appreciating the ease, and reliability of a power driven boat.
     
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  3. WestVanHan
    Joined: Aug 2009
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    WestVanHan Not a Senior Member

    B:

    Just curious if you had considered building the boat (aft) as a widebody.

    You'd gain another 3'+ (?) of interior room which you would appreciate 24/7/365- at the loss of 10 seconds of convenience each time you dock a dozen or two times a year.

    Maybe even conserve the look as well?

    Plus you'd have an extra 3' in which to keep the chicken coop.
     
  4. Boston

    Boston Previous Member

    I gave it some thought back at the beginning of the design process but not much since

    I was after kinda a cross between the Widgeon look and the 57 Flat Top look
    but beefed up a little for coasting and more if possible, which is why I gave it more free board and smaller windows, also the aft cabin being thinner is lighter so Im gaining some stability, might not be much but its something and it all adds up I suppose. The idea is a good one though and since Im drawing up a number of floor plans ( the original I presented some pages back ) I might as well include one or two in a wide body and see what it does to my layout

    cheers
    B

    oh and no
    no chicken coup on this thing
    I'll eat duck in a flash but I kinda hate chicken
    wasi'chu food is bad for you
    I almost never eat the big three
    cows chickens or pigs I pretty much never touch them
    buffalo and duck, goat, elk, venison, almost any game animal or bird and I'll have that grill going in a flash but no chickens for me
     
  5. WestVanHan
    Joined: Aug 2009
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    WestVanHan Not a Senior Member

    OK fair enuff.

    Maybe take a look online at Bluewater Coastals,was on one once and was impressed with the space,layout,and potential seakeeping but was too long for my dock.

    Chicken coop was a joke- forgot the :)
    Just can't help thinking of the hippy-ish barge/boat/trawler I saw a few years ago anchored way off in the middle of nowhere-literally.
    Had chickens,and a mix of dogs,cats,parrots,guinea pigs, etc.
    Methinks they were growing "medicinal herbs" somewhere.

    And why are they called chicken coops?
    Because they have 2 doors,otherwise they'd be called chicken sedans...
     
  6. Boston

    Boston Previous Member

    oh that is funny
    someone posted a pict in the random pictures thread of something sounds very similar to the hippie float you are suggesting

    speaking of which my latest layout looks a bit like this

    [​IMG]

    as apposed to the original first attempt at a layout

    [​IMG]

    the big couch in the back folds out into large bed and the underside of the chest in the middle of the floor is the entertainment center

    the exterior doors of the wheel house got moved back to where they are in the original exterior elevations and the couch and standing desk got larger, the galley got a tad smaller and I eliminated the bar stools that were kinda in the way of access anyway

    [​IMG]

    you can see it has kinda a shorter stumpier look with the increased free board but Im ok with that
    obviously there is a rail going around the cat walks and the raised deck area but they would have muddled the drawing so I left em off for now

    I think I'll make the stairway a bit thinner say 2'6" rather than the 3' it is now, same with the forward stairway which is now a ladder with the engine room access behind it, course I also want an engine service hatch directly above the engine as well

    the head is 3x3.5 and the shower is 3x3.5 which for me at least, being tall, is just barely enough

    the weight came in at ~34,000 fully fueled and stocked
    4000 fuel
    2000 water
    1000 provisions although I could probably throw in another 3000 just in misc. stuff and tools, but I have yet to make that list
     
  7. TollyWally
    Joined: Mar 2005
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    Location: Fox Island

    TollyWally Senior Member

    What horsepower do you think that truck motor puts out @ cruise rpm? What's hp @ top rpm?

    It might not fit your layout but a door all the way aft might be nice when you're tending lines.

    So what's that engine room 400 cubic feet?
    Roughly 550 gallons of fuel? Looks like you need 100 plus cubic feet for tankage.

    Now's the tough part.
     
  8. Boston

    Boston Previous Member

    the engine I have puts out ~185 peak hp at 3000 rpm and ~360 peak T at 1400 rpm
    if I remember its 5 hp/ton so I should be ok given that my weight came in fully loaded at ~34,000 although I can see it ending up close to 20 tons as I already can think of a few things I forgot

    engine room floor area from floor plan B is 105 sq/ft on the floor and 420 cu/ft total
    actually a bit more if you count the area under the stair way which is were the trany will be situated
    fuel tanks are 96x36x18 and hold 300 g each
    there are three water tanks two abaft the engine room and one forward (240 g total) for trim although once I get farther along I might add another one forward

    according to Skene's Elements of Design my center of buoyancy should be center or a bit aft so I need to balance just a bit aft in the end

    calculating the weight was kinda fun actually, I did two comparisons one for a typical frame on keel using the scantlings designated from Skene's book the other I used an egg crate type design with TJI type truss sections, next I'll aim for one using purely cold molded type construction. see how they all stack up but I think in the end the cold molded method will be the lightest with the egg crate coming in a close second

    I need to go check one of my other threads but I think for double diagonal planking there is a small reduction in planking thickness allowed
    although I kept planking thickness and all other scantling considerations identical in my comparison so far just to kinda reduce the number of variables

    question is how to determin the cross sectional sq/in of the stringers for a cold molded hull. Im still waiting for that other book which I think has them

    oh
    a door all the way aft is definitely on the list and in the end I will most likely have one as it seems like a must, Im just playing with various layouts till I find one that seems to fit the bill best
     
  9. TollyWally
    Joined: Mar 2005
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    TollyWally Senior Member

    Cool,
    I think in the end you'll find the differences in wieght not really worth chasing too hard, ease of construction, service, and strength will be more important.

    Shooting from the hip that'l work out to maybe 120-140 hp @ cruise@2200 +-
    Maybe 6-8 gal/hr, say 60=80 hours of fuel @ 8 kts with some reserve

    What ever extra room you can carve out for the engine room you will thank yourself for. I know the tendency is to scrimp and max out living space etc.
    Storage and ease of access for service and physical seperation of clean living area, and grimier working service space is really nice. Really nice.

    You can do a minimalist engine room by copying sailboat guys. You will hate it in the long run. Every system, every hose, clamp, valve,filter, fitting, etc., should be placed with service and replacement foremost in your mind. Deck plates and access covers should be designed in.

    Another item you'll be glad you went to the hassle of putting in with easy access is twin filter systems with a valve to switch between the 2 so you can swap systems while running. Filters don't clog on nice sunny days with wide open spaces. They clog at night during storms near rocks.

    Bla Bla Bla, a boat is a thousand things done right. The devil is in the details.
     
  10. TeddyDiver
    Joined: Dec 2007
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    TeddyDiver Gollywobbler

    And thou some call it having belt and suspenders..
    A separate day tank to be filled throw a separate filter about daily basis is what I'm planning.. bcs if there's some sh** glogging the first filter there's propably some more to do the same for the second one too..
     
  11. FAST FRED
    Joined: Oct 2002
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    FAST FRED Senior Member

    if I remember its 5 hp/ton so I should be ok given that my weight came in fully loaded at ~34,000 although I can see it ending up close to 20 tons as I already can think of a few things I forgot

    5 hp per ton is so the boat can do flank speed SL1.4 into a 40K breeze.

    AS most cruisers care mucho about fuel burn and operate at SL .9 to 1.15 where perhaps 2 hp per ton will work just fine.

    I would attempt to gear and prop the vessel at as near the torque peak as you can. This is called a cruising prop and will keep the fuel burn as low as it gets.

    One caviat is the engine will probably not pull the mfg rated rpm , ever.

    You will need an EGT meter ($100 or so)

    AND you will need to run the engine at full throttle ,to find out the max RPM she will pull.

    This will only be for 30 seconds or so , so no harm will be done.

    Then you need to place a red line on the Tachometer 300RPM below what you got at full throttle.

    That is the NEW "full throttle" , never to be violated.

    The difference in fuel use , depending on the engine , can easily be 50% better , with longer engine life too.

    A CPP would be grand , and even better than the cruising prop IF it fits your expected budget VS the hours per decade you operate.


    Like your design,

    FF
     
  12. Pierre R
    Joined: May 2007
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    Pierre R Senior Member

    Fred what are you basing this on? 50% better?
     
  13. TollyWally
    Joined: Mar 2005
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    TollyWally Senior Member

    It's a luxury but I wouldn't consider not having a fuel flow meter. But then I'm stubborn and opinionated. :)
     
  14. WestVanHan
    Joined: Aug 2009
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    WestVanHan Not a Senior Member

    B

    I was goofing around for a few minutes with MS Paint last nite (after a few home brew cherry ciders) and now I can't find my supposedly saved pic.
    Too much cider I guess...

    Anyways-
    -I made it a wide body aft
    -moved the aft cabin stairs to stbd
    -u shaped galley/stools& counter to port
    -put you sleeping up front
    -moved fwd stairs to port

    Captains chair will need to be raised? So I elevated a platform for that that and intruded beneath it a little into the engine room for freezer/washer.

    Now,can build it so head/shower could be accessed either from aft or forward.

    And because the aft stairs are pushed stbd,there is now room in the pilothouse for a wider sofa/table (spare bed) against the aft pilothouse.

    I'll see if I can find it tonite..going to boat to laze around today
     

  15. Boston

    Boston Previous Member

    I would be very interested to see what you came up with

    a few things though
    moving the stairs off center reduces head room in the stairway considerably, the forward skylight is designed to provide sufficient head room over the forward ladder and the aft set of stairs has a doghouse over it for the same reason. if you look at the starboard exterior elevation you can see a roof line going at the angle of the steps down to the aft cabin roof line. The aft cabin access steps would either need to intrude on the wheel house space significantly or would need to become a ladder in order to eliminate this feature. The feature if placed off center of the aft cabin roof would significantly effect the aesthetics and symmetry of the exterior. I do like the idea of jamming a U shaped galley in somewhere though and thought maybe forward although in rough weather this would not work out so well

    [​IMG]

    [​IMG]

    these two elevations are both from the original floor plan and so will need to be altered in order to reflect the latest version but they are sufficient to show the stair whole design and the raised pilots seat with adjustable height and foot rest. thing even reclines a bit as well. I've build more than my share of chair frames and couches. Only thing that really changed is that the couch got longer the door moved one window bay aft and the coat closet got bigger while the area dedicated to shower and head moved aft a bit. There is also storage under the couch seats.

    also sleeping up front on the hook is a tad uncomfortable if I remember, the ole V berth being largely reserved for storage and the neighbors kids from what I recall. I plan on spending as little time in port as possible although if I can land a job as a shipwright I might find myself on a mooring somewhere

    my galley I really dislike so far and I've got to do something to improve on it

    will be interesting to see what you have drawn so please feel free to suggest away.

    cheers
    B
     
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