Motor Sailers?

Discussion in 'Motorsailers' started by Viceroy, Apr 2, 2002.

  1. Lyle Creffield
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    Lyle Creffield Junior Member

    Hi F Fred
    Pardon my ignorance what does EGT stand for?

    lyle
     
  2. Redsky
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    Redsky Senior Member

    exhaust tempature guage espically on a turbodesil like many are now a days to high a exhaust temp causes the lubricant reaching the turbo to break down and then either the turbo freseses up or it spits the impeller , a normaly asperated desil can be overloaded that way too but it harder to do..depending on your rig.
     
  3. Lyle Creffield
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    Lyle Creffield Junior Member

    Re: ETG

    Thanks

    Whats wrong on these marinised ind./automotive engines (as opposed to a marine diesel with individual cylinder ETG) which occupy most small boat engine rooms to set the RPM required and adjust prop pitch (increase) till black smoke is detected and then depitch the prop till the exhaust is clear that is on engines in good condition

    lyle
     
  4. Redsky
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    Redsky Senior Member

    welll personally i think truck closed cooling system desils dont take well to freshwater cooling it screws up the tempature control /lots of them are computer controlled now/ so the way a truck desil is profiled prety mutch mandates a dry stack and fresh air inflow instead of freshwater.because that how it was designed...and gear ratios. look u can have a drag racer machien shop place shorten the axels down as mutch as possable on 2 matching truck diff's keeping the brakes and air cans ,and straight locked diff mount 1 so one axel end mates up the truck rig bolt pattern with a flex u joint to end of prop shaft mount the 2nd so one bolt pattern ring conncts to the pinion u joint of the 1 diff connect original drivshaft to trans agian and u have something all set up drivetrain wise depending on space u have avaliable...with 3 axels u can do 2 shafts 1 engine. and u end up with under way power take offs too
     
  5. Redsky
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    Redsky Senior Member

    so another question on say 40-60 m boats...1 big mast or 2 slightly smaller masts, in general?
     
  6. Vega
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    Vega Senior Member

    On April 2005, Bluewater sailing magazine published a very good article about Motorsailers. They call it a "report" and it's a kind of well done summary on the subject.

    Most of the things said there have been already said here, in this forum.

    I have made a resumeé, but you can read the full article here:

    http://www.bwsailing.com/Merchant2/merchant.mv?Screen=PROD&Store_Code=BWSC&Product_Code=0405


    "The new generation of motorsailers might be the biggest design evolution since the Bermudan rig

    Motorsailing is the dark secret of most cruisers; ask any cruiser how often they run the engine while sailing and the answer may surprise you, given that they are on a sailboat, designed to make way without the use of an engine. .....

    The response from designers has been two-fold.

    Engines

    Today's boats commonly have much larger engines than those installed in previous years. Arthur Beiser, in his book The Proper Yacht, published in 1966, said that 1.5 horsepower per 1,000 pounds of displacement was "a good preliminary figure" and that two horsepower per 1,000 pounds was "about as much as a sailboat hull can ever make use of." Eric Hiscock in Cruising Under Sail (1950) was of the opinion that 1.5 horsepower per 1,000 pounds was enough to "drive the yacht against a strong wind and a steep sea," and that for "normal use as an auxiliary," one-half horsepower per 1,000 pounds "should be enough."
    A look around at some of today's cruisers gives a wide range of horsepower to displacement ratios. The Hallberg-Rassy 46 has 2.69 horsepower per 1,000 pounds of displacement; Dudley Dix's Shearwater 45 is 1.81 per 1,000 pounds; the Oyster 45 is 2.2 per 1,000 pounds; the Catalina 470 is 2.89 per 1,000 pounds and Beneteau's Oceanis 461 is 3.73 per 1,000 pounds. It seems that two horsepower per 1,000 pounds of displacement is nearly the norm, with higher numbers seen more than lower ones: Engines are getting lighter and more powerful.

    The change in hull shapes

    The other trend is the change in hull shapes, from narrow, deep boats with similar wetted areas fore and aft of the keel to wider hulls with more moderate deadrise. The wetted area aft of the keel is broader and much flatter than in years past, while the bow has a more circular cross section. With the boats capable of more speed under power, more flotation must be designed into the stern to prevent it from squatting when at hull speed. ....

    But even boats with hull shapes designed to optimize sailing (rather than motoring) have bigger motors than in the past, so how are we to define a motorsailer? ...

    ... We certainly need a better definition than engine size or sailing ability.
    Bob Perry, a designer with a fair number of motorsailers to his credit, thinks this might be, if not the best, the easiest definition because "the other indicators are all over the map."
    David Pedrick, whose latest motorsailer, MITseaAH, breaks some very new ground .. A motorsailer "might have three times the engine size of a sailing auxiliary with the same displacement," says Pedrick.
    .....Another defining aspect is the sail area-to-displacement ratio (SA/D). Anything less than 13 certainly qualifies here, but designers are now drawing motorsailers with more sail area than ever before, so this, too, is not always accurate. Ted Hood's No Compromise 54 (reviewed in BWS February 2005) has an SA/D of 20.3, for example, with 7.4 horsepower per 1,000 pounds displacement.
    ....
    The prismatic coefficient

    Most sailboats have a PC of .50 to .55, perhaps .56. Powerboats, with a "fuller" aft and stern section, are typically .60, perhaps a little higher.
    A fuller stern section counteracts the squatting stern by providing buoyancy aft, thus allowing the boat to go faster. If motorsailers are to excel in the powering mode, they will have a higher PC, and this is the case with some of the more successful recent designs.
    ..
    The Bruckmann 50 displaces 45,000 pounds ready to sail and with its 140-horsepower Yanmar has 3.2 horsepower per 1,000 pounds and an SA/D of 14.35 with a displacement/length ratio (D/L) of 268 and a PC "closer to .60," says Ellis. ...

    The Mandarin 52 is made in Zhuhai, China, by Seahorse Yachts to a Blaine Seeley design. ..The hull, ... is also used in their 52-foot trawler, and the Mandarin 52 is a boat the builder happily says will work best with liberal use of the engine. With a PC of .62, the 50,000-pound displacement sloop has a beam of 15 feet with a 46-foot waterline. With a 220-horsepower Cummins turbo diesel turning over at 1,660 rpm, its most efficient speed, the builder claims the boat will make 7.2 to 7.3 knots at 2.7 to 2.9 gallons per hour without use of the sails.

    From Finland comes Nauticat, building a line of pilothouse yachts from 33 to 50 feet. Nauticat defines their range of boats as being either pilothouse sailing vessels or motorsailers, with the difference in part whether the boat is faster under power or sail.
    ....
    Bob Perry has been designing motorsailers for some time, ... In 1995 he designed a 48-foot center-cockpit ketch with inside steering (in addition to a proper binnacle with a wheel in the cockpit) and a very respectable displacement/length ratio of 185. The SA/D of 14.28 is at the high end of what is usually thought of as motorsailer territory, and the hull shows more genes from sailboats than motorboats. The PC is .54 and the boat, only one of which was built, had a 140-horsepower Yanmar for 3.4 horsepower per 1,000 pounds. "It really sailed and motored well," says Perry. ...

    Of more recent vintage is the Sawyer 45, a 45-foot, ..The inside steering station is located in the aft starboard corner of the raised saloon/pilothouse, and although it has a wheel, "the reality is that you don't need a wheel, only a joystick," says Perry, "but some people like the looks of a wheel." Ever the logical designer, he notes that most sailing is done with an autopilot and, at least on a motorsailer, there will be no shortage of electricity or even hydraulic power to operate an autopilot. The Sawyer 45 has a PC of .54.
    ....
    Fisher Yachts drew design inspiration from the proven seaworthy lines of North Sea fishing trawlers to produce boats that are sturdy, seaworthy and dry, even if they are not the sort of boat that will produce the most exciting performance under sail. ...
    ....
    The Puffin series from the Dutch yard of De Gier & Bezaan, drawn by Olivier F. van Meer Design, exemplifies the workboat aspect of some motorsailers. ... The Puffin 42 is a plumb-bowed pilothouse motor-sailer built of steel (or aluminum) with a cutter rig. The 42 displaces 43,000 pounds with a sail area of 1,120 square feet and an 83-horsepower Deutz diesel. The horsepower-to-displacement ratio is 1.93 per 1,000 pounds, the SA/D is 14.72. The hull, with a PC of .54, has full sections throughout, so that the boat can be left to dry on a tidal beach. The four-foot draft becomes eight feet with the 2,600-pound centerboard down.....

    Other designers take a somewhat different tack for their motorsailers, taking their cues from motor vessels with subtle changes in hull shape, adding ballast and putting a sailing rig on it. While the gene pool of these vessels is closer to that of motoring than sailing, they are certainly more than a motorboat with a steadying sail.

    Chuck Paine's Steadysailer takes design elements from workboats and sailing yachts to produce a boat that will proceed at nine knots under nearly any condition, with a range of 3,000 miles under power alone. ...."it really is a motorsailer," says Paine, "the engine will run all the time," with assistance from the sails...... ("it's kind of a big Lightning," says Ed Joy, lead designer on the Steadysailer project at Chuck Paine Yacht Design) is a large part of the design's success. Projected fuel burn rate is 3.25 gallons per hour at eight knots, assuming full tanks, fully stocked for cruising and "assuming seaway," says Joy.
    The boat displaces 48,900pounds at full load, giving the boat 2.14 horsepower per 1,000 pounds displacement. This is rather low for a motorsailer, but the hull shape allows the use of a smaller engine with a resultant gain in fuel economy.
    ... An A-framed outrigger hangs out each side to rig the paravanes that will steady the boat on the downwind points of sail favored by cruisers. ...

    BlueWater Sailing thoughts

    When considering the purchase of a motorsailer, examine your personal sailing style to narrow your choices.

    The shape of the hull will tell you much about how the designer intended the boat to be used.

    If it has an immersed transom with flat-buttock sections, then it will be more comfortable with the engine running. While that doesn't mean it won't sail, it does mean that it will motor well, probably faster than it will go under sail alone.

    The motorsailers of the past were sometimes referred to as "60 to 40" boats, meaning they were 60-percent motorboats. While today's boats perform better under power than their forebears, they are much closer to the goal of being a true 50 to 50 boat. A bit of observation, coupled with knowing what to look for, can tell you which parts of the boat have been designed for which role.

    If you see a hull that looks more like a sailboat, then the boat's best speed will be limited to the 1.35 ratio, whether under sail or power. A big engine will only mean you will be able to maintain speed in adverse conditions: You won't go any faster...

    The sail area-to-displacement ratio can be useful when examining a motorsailer as with any sailboat. Remember, though, that the higher the number the earlier you have to take in the first reef. Accept that the virtue of a motorsailer is that you can make higher average speeds, which is done by eliminating the slow speeds and continuing to make decent way even in the absence of wind. ...

    Although few motorsailers have adjustable-pitch propellers, BWS thinks they could be a worthwhile option. Typically a motorsailer will be making some way with the sails and only needs, say, 40 horsepower of push to get the boat up to hull speed. With an adjustable prop simply dial up a high pitch and set the engine to run at its most economic speed. ....

    The greater interior volume afforded by most motorsailers can be as much a deciding factor as the comfort and consistent speed. After the first cozy night tending to the inside steering station with cold rain and wind outside, many motorsailors need no more convincing that trading their faithful sailboat was the right idea.

    Some sailors see trawlers as the solution, perhaps adding a steadying sail.
    Consider that a trawler with engine problems is not much more than a hazard to navigation. ...

    The motion of a trawler in a seaway is vastly different from that of any sailboat or motorsailer. Rolling is such a problem that controlling it is a regular topic of discussion at trawler websites and magazines.

    And, there will never be enough wind, at any point of sail, for you to shut off a trawler engine. A good motorsailer can routinely make passages that, if done by a trawler, would be headline news.


    We are not going to go out on any limbs and say which is the best motorsailer. Even more than with sailboats, the design dictates what the boat does best.

    Sailboats only have to sail, but motorsailers have to perform well with two very different motive forces. When done right the solution results in a boat that is comfortable, relatively fast (or at least consistent) and has more room than a comparably sized sailboat.

    There aren't any "pocket" motorsailers as the design requirements virtually assure the boat will be big enough to be comfortable in a seaway.

    With a design that provides an easily driven hull and adequate sail area, the boat will derive maximum efficient speed from each. This will reduce fuel costs, and the smaller sail area will be easier to handle.

    Today's motorsailers are evolving quickly, driven by more knowledgeable owners and designers who derive inspiration from the best boats of the past and improve them with modern design technology and a sure eye".

    by Greg Jones on Bluewater sailing magazine, April 2005

     
  7. Redsky
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    Redsky Senior Member

    another thought....there any info on useing forward and aft props on a MS
     
  8. jimisbell
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    jimisbell Junior Member

    "There aren't any "pocket" motorsailers as the design requirements virtually assure the boat will be big enough to be comfortable in a seaway. "

    I think I would take issue with this statement....unless the referance is only to NEW boats. I think the Albin 25 and 27 aft cockpit motorsailers are definately "pocket" motorsailers and, at least my A25, is comfortable in a seaway..with a small steadying sail up.
     
  9. sharpii2
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    sharpii2 Senior Member

    Interesting article, Vega. Thank you.

    Now for a few observations of my own:

    1.) There may have been a breakdown in trade winds. This may be due to 'Global Warming'. As the Artic and Antartic get warmer, there can be less heat difference between them and the tropics. And that could rob you of reliable winds.

    2.) Todays lighter hulls may need more horsepower per ton because they have less wave penitrating (and gust penitrating) momentum. Like throwing a beach ball up wind as opposed to a soccer ball.

    3.) The more you use an engine, at least in long distance cruising, the smaller the engine should be. The engine's main job is dealing with calms and flukey, unreliable winds. It doesn't take a lot of power to do this. (To drive the boat at about the square root of its waterline in feet times knots). Even then, you are motorsailing.

    If you want to go faster, the sailing rig becomes more and more secondary and smaller. It still does very useful work, even in light winds, and can greatly roll stabilise the boat. The boat will go faster (maybe as much as 50%), but it will need huge tanks. The speed at which it motors and the size of its tanks now become major design considerations. They now greatly effect the hull design itself. The boat looks more and more like a power boat and less and less like a sailboat. This kind of boat is probably the most useful for people who can afford a boat that size. People like that (who can afford the payments) usually have busy lives and must show up at x location at Y time. And that is simply not in a sailboat's DNA. The problem here is voyage time predictability. And unless you have an 'Open' whatever, which with its high peak speeds can raise its average speed, you are simply not going to have it. (maybe thats why most of the sailboats I see are used for around the cans racing.)

    Unless, that is, you are willing to put up with a much lower average speed (an idea I am very interested in promoting). Then you simply have a sailboat with larger tanks. IMHO, a voyaging sail boat that carries enough fuel to motor, exclusively, at least half its designed range, is a motorsailer. Even if it looks like a pure sailboat. IMHO such a boat can be very economical to build (doesn't need a huge rig) easier to use, (the smaller sails are handier), and cheaper to maintain (can get by with a less efficient but sturdier longer, shallower keel and might need fewer mid season haul outs and shallower slips for that reason)

    Bob
     
  10. Sean Herron
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    Sean Herron Senior Member

  11. brian eiland
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    brian eiland Senior Member

    Bluewater Sailing article

    I knew I remembered posting a reference to this good article before....just forgot where I put it:
    (under "Monohull verses Multihull powersailers/motorsailers")
    http://www.boatdesign.net/forums/showpost.php?p=46397&postcount=79
     
  12. Vega
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    Vega Senior Member

    Sorry no to have mentioned that, but I didn’t noticed. Perhaps because you have only quoted a little part of it and probably I didn’t check the link.

    I come over this article while doing a search on the “Puffin 42”.
     
  13. brian eiland
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    brian eiland Senior Member

    Crosslinking Similar Subject Matter

    No problem, you did a much better job of highlighting the article than I did. I just try to crosslink similar subject matter
     
  14. Guillermo
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    Guillermo Ingeniero Naval

    A new PH motorsailer from a well reputed firm: The Island Packet SP Cruiser
    http://www.ipy.com/Default.php?Page=SPCruiser&Language=English
    (Not one of my favourites, though)

    Some calculated data for her (guessing HD)

    Beam/Length Ratio B/L = 2,97
    Ballast/Disp Ratio W/Disp = 0,24
    Displacement/Length Ratio D/L = 223,58
    Sail Area/Disp. Ratio SA/D = 15
    Power/ Disp. Ratio HP/D = 4,76 HP/ton
    Hull speed HSPD = 7,9 Kn
    Potential Maximum Speed PMS = 8,21 Kn
    Velocity Ratio VR = 1,04
    Comfort Safety Factor CSF = 1,85
    Motion Comfort Ratio MCR = 29,57
    Screening Stability Value SSV = 103,67
    Angle of Vanishing Stability AVS = 114,27 º
    Heft Ratio HF = 0,98
    Roll Period T = 2,97 Sec
    Roll Acceleration Acc = 0,12 G's
    Stability Index SI = 0,76
    CE Stability Index STIX = 39 (This one provided at site)
     

    Attached Files:


  15. Guillermo
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    Guillermo Ingeniero Naval

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