Looking for efficient low HP, need opinions!

Discussion in 'Boat Design' started by Wavewacker, Jun 21, 2016.

  1. Wavewacker
    Joined: Aug 2010
    Posts: 696
    Likes: 21, Points: 18, Legacy Rep: 226
    Location: Springfield, Mo.

    Wavewacker Senior Member

    Yes, I read the entire thread and I'd not try that.

    Problem is Bolger has so many designs that like, I'll try to take into consideration my saw kerf on cuts. LOL

    The Jesse Cooper is one, but as I mentioned that's a more difficult, time consuming and a budget buster.

    It's hard to find Bolger plans, I think WoodenBoat had a collection but the links are gone for me. I've been on the Yahoo site and have nothing but difficulty trying to follow those posts, not a Yahoo fan I guess.

    I've been cussing and discussing Bolger boats for about 5+ years now, I came across one of my old posts on another forum from 2011, been in the build spiral for almost 8 years, it's time to act! I went to Harbor Freight yesterday and bought all the bar clamps they had on sale and a few more spring clamps. I'll be looking for a nice hand plane next and pulled some lumber to practice with some techniques. Now, I'm getting serious. I'm going to start cutting wood and making sawdust.

    That said, I'm thinking of venturing out of the box, but not too far out.

    There was a multihull or a large outrigger on one side of a main hull that allowed a cabin to extend off the side over the smaller hull. It was a sail rig and the cabin was arched from midway, bow to aft. This extended offset has the berth, the head forward and a simple galley in the main hull. Seems the main hull beam was about 4 feet, the other hull about a 2 foot beam and the bridge deck about 3 feet of the berth. The main hull was about 24ish LOA but the smaller hull was considerable shorter, might have been 12'.

    But, I haven't been able to find that boat again, I'll keep searching.

    Seems the Folding Schooner could be built in the same or similar manner.

    I know that's more to build, more complex, but that could be pretty roomy on a shorter boat. Don't know, 6' covered deck forward, 12' cabin, 6' open.

    Well, it's an idea. I need to close the book on ideas in a few days and decide on something. :confused:
     
  2. FAST FRED
    Joined: Oct 2002
    Posts: 4,519
    Likes: 109, Points: 63, Legacy Rep: 1009
    Location: Conn in summers , Ortona FL in winter , with big d

    FAST FRED Senior Member

    To operate cheaply it takes a big efficient prop .

    The cheapest way to power a boat might be a gas engine built for yard implements.

    Many will have a 6-1 gearbox built right in.

    Honda has a great reputation , air cooled , so no pumps to repair/replace.Or water winterizing.
     
  3. Rurudyne
    Joined: Mar 2014
    Posts: 1,133
    Likes: 31, Points: 48, Legacy Rep: 155
    Location: North Texas

    Rurudyne Senior Member

    ^ what he said.

    A relatively slow turning, high aspect ratio, large diameter prop is from everything I've heard going to be more efficient, even much more so, than the high speed common fare. Same with paddlewheels where the floats are larger on a bigger wheel.

    The downside is these take more torque to turn them, so various transmission bits (and the hub in the case of a paddlewheel) need to be stronger which helps to drive up initial costs somewhat.

    I've read somewhere (not sure where, easily might have been on this forum) that manufacturers, at least the US ones, prefer the smaller props simply because it lowers their manufacturing costs.
     
  4. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 470, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    I'm currently having this same discussion with a client and efficiency, is much more than a slow spinning big prop. He's interested in one of my designs, but at nearly 30' it's beam and mass make it less than ideal. With some modest rearranging, its fuel consumption could be improved maybe as much as 15%, but what the design really needs is less beam, wetted area and mass, as well as a well thought out drive. Only recently has this seemed to crop up, as most wanting a 30' yacht, knew the GPH rates would be within certain ranges, so designs tended toward specific beam/length ranges, particularly in light of the newer, lighter, high performance diesels available. Asking clients to accept narrow elbow room, in return for half the GPH is a battle, which is where additional length helps, though this has its acceptance problems too.
     
  5. Rurudyne
    Joined: Mar 2014
    Posts: 1,133
    Likes: 31, Points: 48, Legacy Rep: 155
    Location: North Texas

    Rurudyne Senior Member

    Yep. The right wheel only gets you as good as your hull allows. You pros have your work cut out for you just on the psychology of boats front.
     
  6. Wavewacker
    Joined: Aug 2010
    Posts: 696
    Likes: 21, Points: 18, Legacy Rep: 226
    Location: Springfield, Mo.

    Wavewacker Senior Member

    Fred, that's a great option and I like that for this boat. The Honda seems to be quieter than others but they are rather loud. When I was a kid we put a motorcycle engine on a go-kart, I don't know but that might work too as an I/O. I think some still makes an OB with a similar engine, there may be kits available to adapt out drives or lower units.

    A paddlewheel looks (and sounds) cool, especially on the river, but it wouldn't be practical for us.

    Rurdyne, there certainly is a bit of psychology in dealing with yachties! (No offense anyone, LOL) :) Same goes for newbies too.

    As to design, I'm a newbie, that's why I'm here asking.

    PAR, then I'll assume the proa idea isn't something to try. With a 4' beam at the bottom I was looking for more stability along with more usable space.

    As to engine and burn rates, I'll ask the question which seems obvious, is it better to run a 20 hp at half throttle than a 10hp wide open? I'd think it would be very close but there arte many other advantages to the 20hp working half as hard for hours.

    Going back toward Bolger's boats as suggested; I don't know the relationship of Michalak's line up but it looks like he's doing Bolger boats, those found were;

    Petesboat, 24x7 is okay with 15 hp.

    Jewelbox 19x6

    Dani Jay 20x6, has the roof I was describing earlier.

    Harmonica needs to be stretched, same with Campjon

    The AF 4 Grande at 22x6.5 would do the trick but it's probably a long build that would test my skills, I'm skeptical.

    Duckworks doesn't have Bolger on the site as a designer.

    Can't think of the name of it but Bolger also had a cruising camper, a tri toon with a bolt on bow that used low power, but another difficult build.

    I don't know what to think about the Eco 62 houseboat, about 20x8 but it is has a low power requirement, designed by Kohler. Mmmmm, no, not for the first boat. :)
     
  7. Rurudyne
    Joined: Mar 2014
    Posts: 1,133
    Likes: 31, Points: 48, Legacy Rep: 155
    Location: North Texas

    Rurudyne Senior Member

  8. Wavewacker
    Joined: Aug 2010
    Posts: 696
    Likes: 21, Points: 18, Legacy Rep: 226
    Location: Springfield, Mo.

    Wavewacker Senior Member

    Yes, I know of the TN and the ID and the WY, all great but too big! I'll search for the T35 and I've seen that side wheeler in the gallery, hey, how about putting a jeep frame and running gear on a steel hull, a 4x4 paddlewheeler! LOL, I don't think so :D
     
  9. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 470, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Bolger designs are tightly control by Susanne and both he and she have always be a bit eclectic about getting them out there. A nearly complete list of what's available can be seen at:

    http://hallman.org/bolger/isometrics.html

    The long and lean Bolger cruisers are comfortable, because of the reasons I previously stated, but you do have to live with the compromises of these design approaches. If you decrease the B/L ratios, efficiency quickly drops off and power requirements quickly rise.

    I've got a few Honda outboards and have found them to be the least noisy of them all. Given engine sizing, they last longer if not working as hard as they need to during general propulsion requirements. Ideally, it should be matched, so it can run in it's ideal power band most of the time. Also, I've never seen a cobbled together, home made unit that came close to the efficiency of the manufactured outboards or inboards. I've tried hard to do so, but I always got beat in some area, often weight, noise and gear ratio choices, kicked my butt.

    Back to the Bolger and Michalak designs, I've found you have to really like these puppies, to get around the in person aestedics of these slab sided approaches. On paper they may look cool, but in person they look like someone forgot to do something during the build. The only ones that seem to avoid this are the stylized power cruisers like Sneakeasy. They have enough era derived visuals, to make you overlook the slab sidedness thing. In you case I suspect accommodations and efficiency are higher up the priority list, than aestedics, but it's just as easy to build an ugly boat as a good looking one, so why compromise in this regard.

    Decide what's the minimum beam you can live with and find a design, shorter than the length you need, but with this beam. You can usually then stretch it out, gaining efficiency and accommodations, while retaining the integrity of the lines. Use 20% as the max stretch, so if looking for a 24' hull, find a skinny 20'er and stretch it up. Unfortunately, in smaller sizes many designs just max out the trailerable beam and work from there, but if you look at some older designs, you'll find this less true.
     
  10. Rurudyne
    Joined: Mar 2014
    Posts: 1,133
    Likes: 31, Points: 48, Legacy Rep: 155
    Location: North Texas

    Rurudyne Senior Member

    Thing about in line paddlewheels is you have to run the rear one faster for it to do any good.
     
  11. Wavewacker
    Joined: Aug 2010
    Posts: 696
    Likes: 21, Points: 18, Legacy Rep: 226
    Location: Springfield, Mo.

    Wavewacker Senior Member

    Thanks PAR, That site has the largest inventory for one designer I've seen I think and I see what you mean, they also have the shortest description for each boat.

    I wouldn't attempt to match the technology of modern OBs, even with less efficiency, more weight and the cons of it all, an air cooled I/O, say tacked to a Merc Cruise 140 might be hundreds or dollars instead of thousands. It's that margin propensity of consumption you described earlier. Just a thought but I'm aware too of penny wise and pound foolish. And, I'm not going to use a paddlewheel, I can picture that crawling over a sandbar, LOL.

    With ply on frame, screwed and glued, I'm thinking a 5/6 degree flare on the sides could easily be done, I'm also wanting a high freeboard, at about 32 inches I might gain another foot of interior beam at the top. So, if I could make that 5' midway, that might work with a 4' beam at the bottom, that's about as lean as I could go, it simplifies building too. At 24 feet that would still be a big boat for us.

    I guess a dozen carriage bolts could bolt two half together, each 12' in length. The aft section might hinge over the forward cabin, that would really ease transportation.

    The thing about running rivers is I'll be a few hundred miles away after an outing, I can't carry my truck or get someone to haul me back, so the boat needs to go on a U-Haul flatbed and a rented truck can get us home. Having a flat bottom would be better in that respect not having to carry or build a cradle for the trailer. I can still have a pointy bow.

    Someone said there's no such thing as an ugly wood boat (LOL) but I agree, I hope it looks like a decent boat, I'll sand and sand and sand, probably paint and sand some more and paint it again.

    I've been doing exactly that, thinking within the 20% stretch following the designed contour going aft or working midway.

    Really appreciate the input! :)
     
  12. nzboy
    Joined: Apr 2011
    Posts: 154
    Likes: 4, Points: 18, Legacy Rep: 36
    Location: nz

    nzboy Senior Member

    When you put all your requirements .The picture comes out a bit like this .

    1)Plywood on frame is the cheapest
    2) trailer sailer hull would be most versatile vee and single chine
    3) modified higher sides with cabin of standing height
    4)Glen L19 would a good start
    So it would be simple to extend sides I would put a 200mm by 30mm
    keelson so you can sit on a flat bed with 2 200mm by 50mm knotched with vees for a cradle
    dsn-g19c.jpg

    dsn-g19c2.jpg
     
  13. nzboy
    Joined: Apr 2011
    Posts: 154
    Likes: 4, Points: 18, Legacy Rep: 36
    Location: nz

    nzboy Senior Member

    Houseboats on planning hulls

    With all the hype of putting houseboats on pontoons ,just build a houseboat
    on a planning hull and you can go skiing too! These are from Glen L for plywood construction Probably need a bit more then 10hp though ! (maybe our SOR is up to 20hp now)
    dsn-gypc.jpg

    dsn-gype.jpg

    dsn-qstc.jpg

    dsn-gyplc.jpg

    dsn-qstlb.jpg
     
  14. Wavewacker
    Joined: Aug 2010
    Posts: 696
    Likes: 21, Points: 18, Legacy Rep: 226
    Location: Springfield, Mo.

    Wavewacker Senior Member

    Hi NZboy, yes that L-19 is very much along the lines of what we need, I've been through the Glen-L site and I didn't find any dory or sharpie or garvey meeting the draft requirements, most are over 2 feet.

    On our local rivers, depending on the time of year, I'd be buried on a sand bar with a 2' draft. The White and Buffalo Rivers are very scenic and great to travel but you won't do that all the way with a 2 foot draft, much less our Current River.

    I also see where my SOR mentioned the gulf about a 10% chance, but a chance and the rest with rivers, mentioning major rivers. After more thought, the use may be equal with respect to smaller rivers and lakes as with those major rivers and very little use in open waters. For a small boat at 24-26', the lakes around here can get choppy, especially on busy weekends.

    As much as I'd like the comfort of the Queen Mary, the ability to haul cargo, cruise efficiently with the lower end of the HP spectrum, extreme shallow draft requires us to compromise, looks like more of a flat bottom boat than a V.

    May be PAR has a compromise. :)
     

  15. nzboy
    Joined: Apr 2011
    Posts: 154
    Likes: 4, Points: 18, Legacy Rep: 36
    Location: nz

    nzboy Senior Member

    An enlarged to 20ft with a bit bigger beam version of Pauls digger I think would be the answer .To get 2 berths side by side you need 2 by 700mm plus minimum gap 400mm so hence 2.1 beam or shower -toilet 750 plus corridor 600mm plus kitchen bench 400mm for example I would have light frames and a 150 by 30 keelson to stiffen the bottom
    BlogProfile.jpg
     
Loading...
Similar Threads
  1. robmcg25
    Replies:
    41
    Views:
    866
  2. Schoolbus
    Replies:
    23
    Views:
    1,225
  3. upchurchmr
    Replies:
    3
    Views:
    779
  4. MurphyLaw
    Replies:
    4
    Views:
    532
  5. Wellington
    Replies:
    8
    Views:
    778
  6. Wellington
    Replies:
    12
    Views:
    977
  7. bjdbowman
    Replies:
    22
    Views:
    2,250
  8. Barron Cohen
    Replies:
    5
    Views:
    881
  9. George Gottlieb
    Replies:
    12
    Views:
    1,012
  10. xellz
    Replies:
    36
    Views:
    2,825
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.