turning a sailboat into a motorsailor

Discussion in 'Motorsailers' started by Dave Gudeman, Dec 12, 2009.

  1. Wavewacker
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    Wavewacker Senior Member

    FF, can you clarify that last sentence? :confused:
     
  2. viking north
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    viking north VINLAND

    Weight within reason is a plus in heavy weather and when I think of a vessel I think motorsailer (cruiser), minimum 50/50 rating, as such displacement is always on the plus side. One problem with motorsailing with modern small high speed diesels is the low RPM typically run. These engines like the higher RPM to keep them clean running (less to no carbon build up) I make it a rule to drop sails and run the diesel full to hull speed on the last leg inbound or the first leg outward bound. Something in the order of a minimum 6 to 1 motorsail to motor only. I have not based this on any specs. it's just a ratio I have used over the years and seems to satisfy the goal of preventing carbon build up.
    The ideal motorsailer setup would be a controllable variable pitch prop to motorsail while keeping the RPM's to a more desireable level. However this set up cost half the price of the engine so it's not within my budget.
     
    Last edited: Oct 21, 2011
  3. FAST FRED
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    FAST FRED Senior Member

    Most boats are built by yards that wish to profit from the construction and sale..

    So the engine installed may not be the "ideal" engine , but simply what was cheap, or the advertising dept thought woulds sell.

    "Bigger is Better" does not really work on diesel engines which are most efficient at high loading.

    So many displacement cruisers would be better served with loads smaller engines.

    The CPP is an attempt at loading better at low speeds , and will allow a really efficient large diameter prop to not handycap the boat under sail.

    Today the old 50/50 concept is dead.

    A 90/90 is the norm.

    The boat is 100% sailboat , but 10% must be deducted for the engine weight , shafting , prop drag and fuel tanks and their volume and weight.

    As a displacement power boat 10% must be deducted for dragging the mast and rigging, as well as the hassle of more keel area and weight .Even tho this improves the ride and survival in a grounding.And the cabins can seldom be 3 stories tall.
     
  4. sabahcat
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    sabahcat Senior Member

    But that heavy overbuild is made from something, more resin more glass = more $$$

    You can have a boat with displacement of 8500kg
    I can build it from solid glass or maybe aluminium and have it splash at 7500kg allowing 1000kg for bodies and beer

    Or I can build a sandwich in Kiri and epoxy and have it splash at 5000kg allowing 3500kg for bodies and beer and a pole and pole dancers and and and


    Having seen and been involved in some destructive testing over the years I can assure you that "some" lighter sandwiches are stronger than what would be considered heavy and "strong"
     
  5. viking north
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    viking north VINLAND

    90/90 -- Again that elusive definition of a motorsailer --I think more in the designs of William Hann as the powerboat extreme of motorsailers. Some being in the (80/20) (70/30) (power to sail) range, where in reality they are a power boat using a steady sail. Not much if any sailing ability--maybe reaching a little more than 1/2 hull speed on a beam or following wind. Absolutely no windward ability. I recall a few of his designs would have fallen into the 50/50 range,( some but poor windward ability). I think thats as good as it gets for his motorsailer vessels. The next two well known would possibly be Fishers and Naudicats. I am only familiar with the older models which would struggle to get to the 40/60 (motor to sail )range. These can attain hull speed on a beam or following wind and have mediocre to poor windward ability. I've always considered a 30/70 motorsailer more into the heavy cruising sailboat range. In my old school thinking, a 90/90 would be an excellent sailer on all points and slightly overpowered motor wise. Hey maybe i'm behind the times :)-- in a new system of ratings, if there ever really was a classification for motorsailers. My goal for my build is in the 30/70 range, thus so much time in the keel work, however the proof will be in the pudding so to say. I do like the displacement to be on the heavy side for these northern waters. From my experience light hulls and heavy seas are not a good mix.

    A yacht is not defined by the vessel but by the care and love of her owner--
     
  6. FAST FRED
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    FAST FRED Senior Member

    But that heavy overbuild is made from something, more resin more glass = more $$$

    Older boats were built with polly resin costing under 20c a pound and fear (no understanding) of the material.

    I worked on an Aero Marine 41 ft Rhodes , built with cloth , no matt or roving , an inch thick, like an aircraft radar dome.

    She is now over 50 years old and still almost perfect.Another 50 should not be a problem.

    Many older boats are 100% overbuilt by todays "standards", and cost little so are good candidates to use as a motor vessel.

    "maybe reaching a little more than 1/2 hull speed on a beam or following wind"

    Most long range power boats will travel at SL .9 to 1.15 , if the owner is paying for the fuel.

    50% if "hull speed" SL 1.34 is about SL .7 , not that far from SL.9 easy to enjoy as it is free!!!

    "Hull speed" is a great concept for sailors as the wind is free ,

    but most motoring cruisers will prefer to save 2/3 on the fuel bill by running a K or 2 slower.

    ON the East coast ICW the sailors with a 36 ft lwl, may shoot for 6.5 to 7K as transit speed , not 9K at FLANK.

    FF
     
  7. Wavewacker
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    Wavewacker Senior Member

    I'm not looking at it like that Fred, sails and rigging wear out and they are not free. Cheap rigging and used sailes bought on the cheap could get you stranded. Just as a old engine puffing black smoke.

    Dave got a boat! Wonder what he got?

    My conclusion to having speed and a liveabord is two boats! I think a nice RIB would be fun and it goes on deck or hangs off the davits.

    Was I reading correctly that a long narrow boat could be under powered by a diesel for cruising? What's wrong with using an outboard and a power prop that can be raised for sailing?
     
  8. FAST FRED
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    FAST FRED Senior Member

    "I'm not looking at it like that Fred, sails and rigging wear out and they are not free. Cheap rigging and used sailes bought on the cheap could get you stranded. Just as a old engine puffing black smoke. "

    Operating trash is always extra work, but in today's boat market there are tons of fine CHEAP boats to be found.

    "Was I reading correctly that a long narrow boat could be under powered by a diesel for cruising? What's wrong with using an outboard and a power prop that can be raised for sailing?"

    A long narrow boat IS easier to push at any speed. Weather it takes 2hp per ton to reach SL1 in the skinney boat or 3 hp per ton for the fatty, the boat will cruise with that power put into the water..

    Weather its from a diesel , gas or electric motor , and if the engine is operating in its efficient range will decide operating cost per mile, and perhaps engine longevity.
     
  9. souljour2000
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    souljour2000 Senior Member

    My 9.9 Merc sailpower pushes my Columbia 29 and her 8,400 lb disp. to hull speed though she's a "skinny" at 8 ft beam. I've even had a 5hp 2-stroke on her once that pushed her at almost 4 kts.
     
  10. viking north
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    viking north VINLAND

    Outboards are noted to be finniky-- short life span--too much electronics and moving parts--hard and expensive to work on -- hard to get parts in remote locations --easily stolen and messes up the stern area access. A small in board diesel a much better choice any day of the week.
     
  11. souljour2000
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    souljour2000 Senior Member

    Probably true,,a diesel would be nice...but at least the boat I have heaves to well and the outboard is more for utility and lazy moments...the Merc is a fairly reliable model and parts easy to procure...I have less drag underway with the outboard in the up position...It it is fairly exposed to following seas and needs a good rinse in such occasions...but the space the Atomic 4 formerly occupied has also given me more room for stowage... for Florida coastal cruising with an eye to the weather this set-up has been pretty good so far. But I think we have gotten off the thread..my boat is not really a classic motor sailor without a much more efficient 4-stroke or a diesel,
     
  12. Wavewacker
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    Wavewacker Senior Member

    Agreed Fred...I was really just speaking to the "free" part. I'd like a motorsailor so I could be lazy and motor and when I felt like it, sail some, like when I'm out a fuel....LOL. But going with wind power is often referred to as "free power" but not really since you need the equipment to capture what comes along, maintain it and replace it, which is far from free.

    Using a diesel without a load I thought was harder on them than the designed load....may not get the best burn rate but I'd rather have my engine last longer if that was the best way to run it....

    Viking, LOL, yep, I have heard that too, I'd hate to smell deisel fuel and pay more for it too, even knowing diesel has more btu's per bang in it than regular. Gas goes boom eaiser than diesel too. But it depends on the cruising grounds as well. I'll never get to Midway or off the Ivory Coast, but there are areas along the rivers, Mississippi, Missouri, White River where you won't find diesel unlessyou can hitch a ride to a truck stop. A small, limited range boat, like the Lancer won't hold enough fuel for the 400 mile black hole down the Old Muddy (unless you took extra tanks). Sailing can be a chore there as well.

    I think doing 50 to 70 miles a day, gunkholing, off the beaten path away from commercial shipping a gas outboard would be better. They do wear out, but buying a new on is probably less than an overhaul on the diesel, especially on boats where they have been put in with a shoe horn.

    Some have a motor well just forward of the stern so entry is not that big of a deal, sure it depends on the boat. I like swim ladders and platforms. :D

    Now, I thought we were talk'n a 24 to 32 footer, with a bigger boat I'd start leaning towar the diesel as well with greater capacity and range. But turning a small sailboat into a motorsailor, if it didn't already have the engine, I'd certainly go with an outboard. They have really improved over the years....
     
  13. souljour2000
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    souljour2000 Senior Member

    The only part I dislike about about motor-sailing is the motor-part.....i.e., the loudness of my 2-stroke Merc 9.9....hope to afford a 4-stroke someday...cleaner... quieter
     
  14. viking north
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    viking north VINLAND

    Agreed for coastal work an outboard is just fine--I was thinking more in the term of far away places. The motor well is definately the best setup and with a basic custom built sliding set up a simple handle lever will pull it up clear of the water. Less chance of theft and more convenient to work on. I've Seen one set up where the guy had a hinged internal panel that dropped down and locked in place once the motor was raised thus eliminating that suction drag created by the opening. One of the big marine supply dealers here sold a diesel outboard name??? made in Italy.
     

  15. souljour2000
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    souljour2000 Senior Member

    I think sailors from more northern climes or areas with strong tidal currents and bitter cold demand a certain type of motorsailor with a good diesel and here in Florida an entirely different hybrid of a motorsailor might be desirable with just a good dodger/ seahood,outboard auxiliary.... whereas a pilothouse seems wise further north...The Great lakes, NE and Canadian maritimes, Northwest USA,Canada,Alaska,etc and the North Sea sailors and Europeans in general seem to have their own breeds of motorsailors suited to those areas that have evolved. It all depends on what you can afford and what type of sailing you want to primarily do.
     
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