Helm position and prop rotation

Discussion in 'All Things Boats & Boating' started by murdomack, Nov 9, 2007.

  1. murdomack
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    murdomack New Member

    Has anyone got views about the best combination of helm position and the prop rotation with regards to the maneoverability of a single screw long keel vessel. The first boats that I used and owned had the helms to port and right hand props. I always found handling in close situations difficult.
    When I purchased my present vessel it had a port helm and a left hand prop. I found it easy to control and it all felt very natural.
    I re-engined a couple of years ago and installed a larger right hand prop. I feel as if my boat is less controllable than before. The gearbox has a lower ratio in astern than in ahead, this may be part of the reason and I might just need to learn to apply more power to compensate.
    Maybe it is just me, but I think it helps to have the stern pull to the side opposite the helm when giving an astern burst when pulling alongside a pier or pontoon.
     
  2. charmc
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    charmc Senior Member

    Hi, murdo,

    Interestingly, maneuvering in reverse just came up in another thread:
    http://www.boatdesign.net/forums/showthread.php?t=20175 . There's a link to an article on back and fill techniques in which the author claims it's always best to be aggressive on throttle bursts for maximum control.

    Although my single screw boats were all different and had different helm positions, it happened that all had clockwise props, so they all went to port in reverse. I was most comfortable with that and kept the helm hard over to port when backing so she always went port-reverse, starboard-forward. It never mattered where the helm was, or whether the pier was to port or starboard.

    Of course, for me that was because that's the setup I learned on and had the most practice with. I've imagined I'd simply reverese things in my mind for opposite conditions, but I'm always an expert in my own mind. Put me in an actual boat with a counterclockwise prop and I might become a newbie again! :eek: My guess is that, for whatever reason, you're most comfortable with one setup. We're all lazy ******** at heart, I suspect, and we like our comfort. I know I do! :D

    Then again, if your new gearbox really give less power in reverse than the other, that might change the whole feel of the boat.

    I'll be interested in hearing other's thoughts.
     
  3. murdomack
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    murdomack New Member

    Hi Charlie,

    When you say "you're most comfortable with one set up" you describe how I feel. I have read the links you posted and I do most of what is said, still, you can't read it often enough.
    I know that reversing the prop rotation simply means that everything should happen the same way in the opposite direction, but the side that your helm is situated in an enclosed wheelhouse restricts your view of the opposite side.
    If I am single handed and coming alongside a portside pier with my clockwise turning prop, I have the double advantage of perfect visibility and port prop walk to tuck me alongside when I give an astern burst. If, however, the pier is to my starboard side, I have to judge my distance off and try to come alongside in such a way that the boat will be stopped alongside allowing me time to get tied up. In an adverse wind this can sometimes be difficult.
    With the port side helm and the anti-clockwise prop, I had perfect visibility coming in port side to and had my astern starboard prop walk to assist me when coming in starboard side to.
    Having the helm to port with a left hand prop and to starboard with a right hand prop would, in my view, make life easier if single handed and in an enclosed wheelhouse.

    Regards

    Murdo
     
  4. charmc
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    charmc Senior Member

    "Having the helm to port with a left hand prop and to starboard with a right hand prop would, in my view, make life easier if single handed and in an enclosed wheelhouse."

    Murdo,

    I see your point. Maybe one reason I was comfortable approaching from either side (although in a crowded area in high enough wind, it's a ***** no matter what :D ) was because I always had good sight lines; I guess that was something I considered when making a purchase. I do recall some "discussions" with my ex about keeping all privacy curtains open when approaching a berth; she used to close them because that "looked nicer". :mad: Anyway, I think you're right. Coordination between helm location and prop rotation would make life a bit easier for the single-handed skipper.
     
  5. PAR
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    PAR Yacht Designer/Builder

    Typically in small craft, there are two choices for helm location. One assumes the driver will be involved in deckhand duties, the other doesn't. Helm to port is where I place a steering station if the crew will have deck chores. The logic is, the action is always in front of the skipper, port to port over taking, port to docking maneuvering, etc.; the skipper doesn't have to turn his head very far. If the skipper will be grabbing a dock cleat as he slides it into a slip, then the helm is to starboard. The reasoning, most folks are right handed and are more comfortable handling things from the right. Ideally, a central and raised helm location is wise and a feature seen on many working craft, where their size can afford the off set companionway opening.

    Learning how to handle a single screw boat is simply a matter of practice, until muscle memory can guide you through. I react naturally to clock wise or counter clock wise setups, having skippered both many times. My current right hand screw handles easily enough, given the limitations, particularly compared to I/O's and outboard maneuverability. The best advise is to find an out of way place to practice (safe for the boat and to save embarrassment) then spend several hours getting to know the "feel" for the boat. Once you've got a handle on the way she wants to "walk" then you can work it to your advantage. The other option is a bow thruster.
     
  6. marshmat
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    marshmat Senior Member

    Perhaps this is my outboard/sterndrive bias talking (all the power craft I use have vectored-thrust drive systems), but I have a certain preference for a starboard helm. The reason being that with these drives, the boat has no inherent preferred side. But piloting from starboard, there are no crew and passengers to block my view of the "give-way" sector (yield to boats coming from the right). On busy, chaotic waterways like we have around here, this is a significant safety advantage.
    The argument doesn't translate as well, though, to an inboard that does have a preferred side. I think in these boats it really comes down to personal preference, and getting a good feel for your own vessel.
    A suggestion for a practice area that I have heard a few times is to secure a Styrofoam floating dock billet in a secluded area with a couple of 10-lb mushroom anchors. You can easily re-orient this practice pier to whatever wind direction is present, and it can't put so much as a scratch on your hull when you screw up. And nobody can see you screw up while you practice.
     
  7. murdomack
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    murdomack New Member

    Thanks for the replies,

    It's not that I need practise, although any advice is welcome. I have entered every harbour and marina in the west coast of Scotland over the last 30 years, sometimes in quite rough weather and often single-handed or with inexperienced crew. I have also been through the canals many times on my own and visited some North East Ports as well.
    My observation since I changed the set up has been that, although I can still manage, I was more in control with the left handed prop. Par has explained why the helm is usually on the port side and he is probably correct. I would look at trying to change the gearbox and prop, before considering a bow thruster which I know from my previous experience with the vessel is not required, but I don't think I can justify the expense just to make my berthing easier. I will give it another season and try and get used to it.

    Murdo
     
  8. safewalrus
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    safewalrus Ancient Marriner

    Down yer us normally has the steering oar on the steerboard or starboard side! hitting the wall with the larboard or to give it it's modern name the port side! Us finds it pretty simple (mind 'ee the big flat top's have their islands or steering oar on the starboard side and goes starboard side too! guess it prevents them falling over when in port!!

    Other than that I find that PAR is about right, (if'n usin a wheel I prefer the midship position, for the reason PAR gives - good commercial practice!)
     
  9. PAR
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    PAR Yacht Designer/Builder

    I thought port side came to be as it was always the side to the wharf, so's not to crunch the steerboard against it.
     
  10. murdomack
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    murdomack New Member

    Par,
    From what I have read, I think that is correct.

    'Walrus,
    I have been trying to fathom out what a "big flat top" is and I reckon it's an aircraft carrier. Am I right?

    Murdo
     
  11. safewalrus
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    safewalrus Ancient Marriner

    Murdo, you got it - they always have their 'island' on the starboard side (tradition?) and thus tend to go starboard side too only (can't see the port side for obvious reasons!)
     
  12. murdomack
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    murdomack New Member

    Are you sure it's just tradition? I think the US carriers have the "island" to starboard as well (trying to remember all those old films). You may have started another thread there.
     
  13. safewalrus
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    safewalrus Ancient Marriner

    Can't think of ANY carriers with islands not on the starboard side - all copies of the first ones - we invented them and thde ******* improved 'em (got the money), but most all major alterations and improvements are Brit (that Second World War has a lot to answer for), everybody else has just followed on! Our newest ones (if we ever get em) will have two islands - one for the stack and the other for the bridge/flight control BUT STILL ON THE STARBOARD SIDE! Pretty sure its only tradition as most are twin (or more) screwed! Them with more than two normally turn off the middle ones and manouver into and out of port on two!
     
  14. murdomack
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    murdomack New Member

    Here's some info on why it's on the starboard side. I have read this on another website as well, but can't copy it

    http://www.hazegray.org/faq/smn5.htm#E9

    Section E.9: Why starboard side islands?
    Why are aircraft carrier islands always on the starboard side? There are several reasons. Initially the island was placed on the starboard side because early (propeller) aircraft turned to the left more easily (an effect of engine torque). Obviously such an aircraft can execute a wave-off to the left more easily, so the island was put to starboard to be out of the way. There may also be other, minor contributing factors.

    Once the starboard side position was established and a few carriers were built in that configuration, it became difficult to change. Pilots used to landing with the island to their right would be confused on a ship with the island on the other side. There was nothing to be gained by moving the island, so it stayed in the same place. Once angled decks were introduced this became even more important, since the deck angle would have to be changed to move the island.

    There were, however, two carriers with their islands to port. The Japanese Akagi and Hiryu were fitted with port-side islands. Each was meant to work in a tactical formation with a starboard-island ship (Kaga and Soryu respectively); it was thought that putting the islands opposite sides would improve the flight patterns around the carriers. The idea was scrapped after two ships were so fitted, and all later carriers had starboard islands.
     

  15. charmc
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    charmc Senior Member

    Murdo,

    Thanks for that; makes sense. Like many traditions, the practice starts for a good reason, then after times change (jet aircraft) the tradition lives on. I didn't think it had anything at all to do with ship handling, as all carriers are either twin or quad screw, and I've never seen a carrier anywhere within 1000 m of a pier without at least 4 tugs doing the manuvering! :D
     
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