proper helm seat placement

Discussion in 'Boat Design' started by odduck87, Sep 11, 2016.

  1. odduck87
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    odduck87 Junior Member

    I need to know if there are guidelines for helm seat placement in regards to the windshield height. One opinion says your eyes should be 4 inches below the top of the windshield but I don't know if that is an informed opinion. Any suggestions will be appreciated. thanks.
     
  2. gonzo
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    gonzo Senior Member

    Is this an open boat or is there a hardtop on?
     
  3. odduck87
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    odduck87 Junior Member

    It is open but will have a bimini over it but that will be quite a bit over the driver's head due to the layout.
     
  4. tom28571
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    tom28571 Senior Member

    Good vision from the helm is important and there is much more to it than eye location below the windshield top. Other things like trim of the boat, bow height, eye level standing vs seated, etc. Basically, you want to see what is happening all around and especially what is right in front of the boat.
     
  5. mydauphin
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    mydauphin Senior Member

    Also if it a smallish boat, under 40, it might jump around and you don't want the captain to hit his head. Keep that in mind with t-tops etc. I have found most people stand a large portion on the time keep that in mind. A seat just below your standing butt is the way to go.
     
  6. odduck87
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    odduck87 Junior Member

    Thank you. I appreciate your input.
     
  7. PAR
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    PAR Yacht Designer/Builder

    It also depends on what the skipper might need to do. If the boat is small, it's likely they'll need to also participate in deck duties (handling lines, pushing off, etc.), so typically the helm is to starboard, because most are right handed. If the boat is bigger and you'll have crew for deck duties, the helm is to port, so the skipper's eye is directly over a port to port pass.
     
  8. odduck87
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    odduck87 Junior Member

    I'm 24' and to starboard and the wheel is a fixed height. The helm sits atop a mid-cabin and in front of the windshield there is a cabin roof that continues then slopes down to the forward bow. The only way I can see the bow is standing up and I'd like to sit while just cruising inland waters. So it's a dilemma. This is a boat I am rebuilding so have to make a lot of decisions and not just re-do what was there. Thanks for your input.
     
  9. tom28571
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    tom28571 Senior Member

    Yes,

    That is a bad layout. No one can tell you exactly how to rectify it without seeing and checking out the boat, even if it can be reasonably fixed. Most likely, it can be improved though. Some boats and that includes some very popular ones, have poor vision from the helm. Designers worth their salt, will take helm vision into consideration but some just don't.
     
  10. PAR
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    PAR Yacht Designer/Builder

    Post a few photos, showing the profile and approximate helm location "PaintShop'd" if necessary.
     
  11. Barry
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    Barry Senior Member

    Yes there are rules regarding helm seat height placement. H-1 ABYC

    There are about 4 pages dealing with this and I will ATTEMPT to summarize

    There are 4 heights above the floor that are significant

    Standing high eye position 68 inches above the floor
    Standing low eye position 58 inches above the floor

    Seated high eye position 33 inches above the floor
    Seated low eye position 27 inches above the floor
    Any seated height is with the seat compressed,

    For a planing boat, ignore the hump high bow up attitude. For various speeds record
    trim up operating angle.

    Put the boat into a cradle and at the highest bow up operating attitude,

    At either 4 boat lengths or 164 feet forward from the bow which ever is least, set a target
    Verify that the target can be seen from the 4 eye heights listed above if you are designing for a helm that will accommodate standing and seated capabilities

    The target must be seen at an arc of 15 degrees right and left off the line parallel to the keel, but in line with the center of the seat. Ie you can see the target through 30 degrees. This is called the clear sector of visibility

    Additionally, regarding the upper window vision line, when the boat is at max trim, you must be able to see horizontally and forward through the 30 degree arc from these high eye height measurements.

    Assuming a Stbd helm location.
    You must have 90 degrees of visibility to port, and 112.5 degrees to stbd, ( note the .5 degrees)

    Note
    If the boat is designed to be ONLY driven from the seated position, you use the seated measurements
    If the boat is designed to be ONLY driven from the standing position, use the standing measurements
    If the boat is can be driven in both positions, you must meet both guidelines

    If the boat can be driven seated or standing but only meets the standing requirements, then you need to affix a label "Visibility from the seated position is limited"
     
  12. tom28571
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    tom28571 Senior Member

    Barry,

    I have to say that these "rules" make little sense and are at least misleading. Height above the floor (sole) have little bearing on actual eye position on many boats as seat heights and sole levels are so varied. Planing boats for max speed (racing) do have high trim angles of 4 to 5 degrees which tends to limit vision in other cruising boats and should call for low bow height.

    Its not rocket science. Either you can see well from the helm or you can't and such fixed rules as these will not guarantee that.
     
  13. Barry
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    Barry Senior Member

    Hi Tom
    Your are stating that these rules make little sense as and provide a racing boat example as one that might not fit.
    I am only trying summarize what ABYC has written in their requirements or standards.

    I am not here to defend their regulations.

    But if you follow their requirements, you will have unobstructed view forward, and to the sides. If you do not follow their requirements, then perhaps you might not have unobstructed views forward and to the side. The OP was asking if there are requirements and there are.

    There are also some requirements for aft visibility but as well but many boats, we own one made by an international boat builder, that would not meet them.

    If a boat manufacturer were to state that their boats conform to ABYC standards, these standards are those that the manufacturer would have to meet

    Regarding bow up attitudes, which you mentioned. The deeper the V in a planing craft, the higher the bow up attitude for least resistance planing, within a couple of degrees.
     
  14. odduck87
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    odduck87 Junior Member

    thanks for all the input. i am trying to understand what the high and low eye position is. The boat is a 1987, 24' Crestliner Sabre DC that I have been slowly re-building for some time. It probably was a bad design originally but as I play with it, I try to improve where I can but I have limitations. I am using a dual helm seat that faces either forward or back and will be mounted on a box of my construction and hopefully with have a 6" front/back slide. If I can figure out how to post photos of this "Odduck" I will. Another can of worms is asking painters what kind of paint they would use on this welded aluminum boat - it all depends on who you talk to.
     

  15. tom28571
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    tom28571 Senior Member

    Barry,

    No offense intended and I was not contradicting you. My issue is with with blanket rules that have never done a decent job of defining anything over a broad range of applications. The seat and standing height "over the floor" rules are a good example. Without reference to the stature of the pilot, these numbers are useless. A sedan will have very low seat height where standing is not even possible, a center console and many cruisers will often have a seat high enough that the pilot has to climb up into it and the helm on a flybridge is an altogether different case. Windshield dimensions, forward deck height and shape as well as bow height and trim angle should be compared to eye height and are usually much more important than the numbers given in these rules.
     
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