Combination CB trunk / Motor well

Discussion in 'Wooden Boat Building and Restoration' started by wwheeler, Feb 20, 2004.

  1. wwheeler
    Joined: Feb 2004
    Posts: 10
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Coldwater Ontario Canada

    wwheeler Junior Member

    I'm currently pondering the build of a rowing / sailing dory based on an old design (see www.svensons.com). The plan has a sketchy outline for the centreboard, apparently the deal was the readers to the magazine (long since defunct) would send in for the full-size plans, at a cost.

    Dories are typically considered highly seaworthy, though initial stability is low. (However, I'm upgrading from a canoe, so this should not be a problem!) With lots of volume and high seas, it seems to be a good choice for a camping/cruising boat. However, one of the leading disadvantages of a dory design is that the transom is completely unsuited to taking a small "kicker" motor, which I would need. (Long journeys out on Georgian Bay, where it can get pretty nasty.)

    The design options are as follows:

    - install a small motor mount outside on the gunwale. This may be awkward if you're going to bury the rail on a breezy day. You can pull the motor into the boat as required, but that can be awkward too.

    -- install a small electric motor that clamps onto the rudder. This has a somewhat Rube Goldenburgian feel to it, since it has to be home built out of a trolling motor. (and there's all the disadvantages of electric that go with it.

    -- build a small motor well into the floor of the boat. A dory has a fair amount of flat bottom that can be used, but with a centreboard, there's some limitations on the amount of space available.

    As a result, I wondered if it's possible/feasible to build a small motor well that's adjacent to the centreboard. There's would be a need to be able to close it up when not in use, so that it doesn't slosh too badly under certain conditions.
     
  2. gonzo
    Joined: Aug 2002
    Posts: 14,156
    Likes: 544, Points: 123, Legacy Rep: 2031
    Location: Milwaukee, WI

    gonzo Senior Member

    Many have drowned on dories. They are only seaworthy loaded. It takes a lot of skill to handle one in light condition. An electric trolling motor can be installed in the aft edge of the rudder. It can slide up and down.
     
  3. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 473, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    The dory has a number of variations and most are deserving of their reputation, though it must be remembered they were working craft of their day and life and limb at sea for a days effort to bring home the bacon (or cod) wasn't worth what it is today. Safety wasn't the biggest concern of the folks working these boats, load carrying and to some extent speed were the main issues driving the design concept.

    That said, several designers have looked at the dory hull form and made the needed refinements required of boaters today. Typically the dory bottom is made a bit wider, the bow is given more bury, some flare is removed from the topsides (partly as a result of the widened bottom) and in some the rocker is decreased.

    Jay Benford has a line of offshore cruisers ranging from 26 to 37 feet, all economical to build.

    The book "Voyaging on a Small Income" by Pete and Annie Hill aboard "Badger", their 34' Benford dory details how they cruise all over the world on a shoe string.

    There are other designers and I'm sure they can steer you in the right direction.

    Dory hulls do not have to be double ended, the small transom making room for a little kicker . . .
     
  4. gonzo
    Joined: Aug 2002
    Posts: 14,156
    Likes: 544, Points: 123, Legacy Rep: 2031
    Location: Milwaukee, WI

    gonzo Senior Member

    I agree that a modified dory is more suited to modern use. The traditional working type is a bear to handle.
     
  5. wwheeler
    Joined: Feb 2004
    Posts: 10
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Coldwater Ontario Canada

    wwheeler Junior Member

    "An electric trolling motor can be installed in the aft edge of the rudder. It can slide up and down."

    Gonzo, does that mean retaining the whole trolling motor or removing the propeller head from the shaft, and fixing it to the rudder?
     
  6. gonzo
    Joined: Aug 2002
    Posts: 14,156
    Likes: 544, Points: 123, Legacy Rep: 2031
    Location: Milwaukee, WI

    gonzo Senior Member

    The trolling motor attaches to the aft edge of the rudder. One of the advantages is that you steer with the tiller.
     
  7. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 473, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    I posted my version for a trolling motor/ rudder mount in an earlier thread. The benefit of my rig is it is retractable and also removable from inside the cockpit of the boat. On a small sail or rowing craft I don't like the weight hanging off the rudder all the time. There are times when I don't want the thing mounted at all, other times I want it available, but not in the water. The slider thing works, but it's only easy to get at on pretty small boats. With mine the boat can be much larger. It was listed in the "jet Power ..." thread, here's the drawing.

    http://boatdesign.net/forums/attachment.php?attachmentid=1018&stc=1
     
  8. wwheeler
    Joined: Feb 2004
    Posts: 10
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Coldwater Ontario Canada

    wwheeler Junior Member

    Thanks for the replies, but Gonzo I find your warnings about dories a bit dire, considering their long history on the open ocean. Did I mention that I'm a canoeist? I'm planning to use it well-loaded, as a camping boat. Thanks for the thread reference, PAR, I'll follow it up.
     
  9. gonzo
    Joined: Aug 2002
    Posts: 14,156
    Likes: 544, Points: 123, Legacy Rep: 2031
    Location: Milwaukee, WI

    gonzo Senior Member

    They were used loaded in the open ocean by experienced seamen. Even then the loss of life was appalling.
     
  10. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 473, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    I hope Gonzo got the point across about the traditional dory type. They were intended and used with a big load of fish, the shape was to ballast down evenly and predictably, but in fact the design criteria used then (1800's) wasn't what we will accept as reasonable today. Crew and craft losses were high, because the design pursued load carrying ability rather than safety or seaworthiness. In an age of sail, they were handled by men very familiar with the type's quirks and limits. These were men who lived and drank the sea, it was the place for all state of the art and adventure.

    This is not the case now. State of the art as all but left the design of small craft and moved on to the landing of men on the moon, little boxes we can share our thoughts on collectively and the sea is a unforgiving ***** at times (as the widows of the dory fishermen well know) We 21st century small craft putters have taken the great toll of past efforts for granted, in a lot of cases. We forget that Capt. Slocum sailed, what was considered by all a rather small craft of the period, solo around the world, this same boat, much copied and also much improved, is accepted as a yacht, to some a large yacht now.

    The Spray didn't change it's dimensions, but our perceptions of the boat have. In this vain, our ideas concerning much else has also. We all look back to a kinder, gentler, simpler time and forget they wiped their butts with corn cobs, that women were the property of a man, only land owners could vote and our kids were low cost slaves for the house and field, if we couldn't find a factory to chain them into machine for 14 hours a day, six days a week. Ain't so quaint, when we look at it all.

    A modified dory is easy to spot, once you get used to looking at dorys. The previous posts should give you a good idea where to start, though the Chamberlain Dory at the Center for Wooden Boats is a good one (Bud likes it)
     
  11. wwheeler
    Joined: Feb 2004
    Posts: 10
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Coldwater Ontario Canada

    wwheeler Junior Member

    Point well taken about our change in perceptions. I've observed this from working on a farm - the work load and accident rates from 100 years ago would be considered unacceptable today. No wonder life expectancy was about 50 years. However, venturing out into the open ocean with a small open boat is inherently hazardous, regardless of the design.

    I would suggest that the design is not more or less hazardous than many other types, though the initial stability is low. As a thought experiment, compare the stability of a rowing shell, or a typical sailing dinghy. Dories are typically used as recreational rowing craft for light use, not out on the open ocean.

    Many dories being built still, including modified designs such as Swampscott dories, Bolger's Gloucester light dory etc. Similar types such as Oughtred's Caledonia Yawl are reputedly excellent coastal sailors.
     
  12. SeaDrive
    Joined: Feb 2004
    Posts: 223
    Likes: 1, Points: 0, Legacy Rep: 15
    Location: Connecticut

    SeaDrive Senior Member

    If you approach most any experienced small boat designer for a combination row/sail/power boat, he will caution you about being too ambitious. If you add rough water ability, he will send you away as a crackpot.

    I assume you mean the rs_dory. I agree that it looks like a great rough water row boat, but I wonder if it is a good sailboat. A tender form like a dory seems a curious starting point for a rough water sailer. In any event, when a good designer like Bolger or Welsford designs a sailboat 'based on a dory' it usually comes out not much like a dory at all. See Welsford's Walkabout, for example. http://www.duckworksmagazine.com/store/plans/jw/walkabout/index.htm. Note: no allowance for power.

    I think you could put a well for an outboard about where the stern seat is, but 1) it would ruin the interior for camping, 2) it would greatly degrade the boat's rowing and sailing performance. You won't want the propellor in the water when you row, so where does the engine go then? Oars, spars, and engine make for a lot of clutter.

    Finally, there is a lot of benefit in having a contemporary design from a living designer. They answer questions and give advice, and they specify materials that are in the stores today, not ones that dissappeard years ago.
     
  13. wwheeler
    Joined: Feb 2004
    Posts: 10
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Coldwater Ontario Canada

    wwheeler Junior Member

    I appreciate that we want to encourage modern designers, but on the other hand, these designs are untested, and may not be an improvement on older designs. Here's what John Welsford said about his design:

    "I stood the stem and stern up straighter to gain waterline length, rolled the sides out like a Swampscott for heeled stability, decked her ends over to keep her dry both under way and at anchor, and made the ends long and fine so she would row well even when loaded up for a month away."

    [​IMG]
    Comments on the design - at what point does it cease to be a dory? (And yes, maybe it is overkill to have an outboard in a well)
     
  14. Richard Murray
    Joined: Apr 2004
    Posts: 1
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: North Weymouth MA 02191

    Richard Murray New Member

    Dory Shop Lunnenburg Nova Scotia

    The Dory Shop in Lunnenburg Nova Scotia mounts an OB in an engine well for of the rudder in one or more of their dories. You may want to see how they do it:

    http://www.doryshop.com/

    Rich

     

  15. wwheeler
    Joined: Feb 2004
    Posts: 10
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Coldwater Ontario Canada

    wwheeler Junior Member

    Thanks, Richard, very interesting site.
     
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.