Helmsman sight lines

Discussion in 'All Things Boats & Boating' started by fallguy, Jan 31, 2020.

  1. fallguy
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    fallguy Senior Member

    I am trying to determine minimum sightlines for the helm. I remember reading some guidelines somewhere, but I can't recall the source.

    The boat is a 32' powercat with top speeds of under 30 knots. I did a calculation and a helmsman with 66" eye height (me) would be able to see the water about 76 feet in front of the vessel, or about 2 boat lengths not moving.

    I have seen larger vessels back into their slips. Is this why? My aft view is for sure better.

    Anyhow, not sure where I did the reading. Send me thoughts. I dropped the front of the cabin 5" for better sightlines and reduced my calculated distance to see from 97 feet to the 76 feet.
     
  2. Ad Hoc
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    Ad Hoc Naval Architect

    The most relevant rules, would be the HSC code:

    15.3 Field of vision from the operating compartment

    15.3.1 The operating station shall be placed above all other superstructures so that the
    operating crew are able to gain a view all round the horizon from the navigating workstation.
    Where it is impractical to meet the requirements of this paragraph from a single navigating
    workstation, the operating station shall be designed so that an all-round view of the horizon
    is obtained by using two navigating workstations combined or by any other means to the
    satisfaction of the Administration.

    15.3.2 Blind sectors shall be as few and as small as possible, and not adversely affect the
    keeping of a safe look-out from the operating station. If stiffeners between windows are to
    be covered, this shall not cause further obstruction inside the wheelhouse.

    15.3.3 The total arc of blind sectors from right ahead to 22.5deg abaft the beam on either
    side shall not exceed 20deg. Each individual blind sector shall not exceed 5deg. The clear sector
    between two blind sectors shall not be less than 10deg.

    15.3.4 Where it is considered necessary by the Administration, the field of vision from the
    navigating workstation shall permit the navigators from this position to utilize leading marks
    astern of the craft for track monitoring.

    15.3.5 The view of the sea surface from the operating station, when the navigators are
    seated, shall not be obscured by more than one craft length forward of the bow to 90deg on
    either side irrespective of the craft's draught, trim and deck cargo.

    15.3.6 The field of vision from the docking workstation, if remote from the operating
    station, shall permit one navigator to safely manoeuvre the craft to a berth.

    Refer to BS EN ISO 8468, Ship’s bridge layout and associated equipment – Requirements
    and guidelines.
     
  3. fallguy
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    fallguy Senior Member

    One ship length.

    We will have to verify my math and adjust.

    Thanks
     
  4. TANSL
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    TANSL Senior Member

    Perfect, although, it could arrive up to one and a half times or two times the length.
     
  5. DCockey
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    DCockey Senior Member

    ABYC H-1 Field of Vision From The Helm Position Standards Index (Standards by Division) - American Boat and Yacht Council https://abycinc.org/page/CopyofStandardsInd > Hull Division > Hull Performance > H-1

    ABYC are the most commonly used standards for recreational boats sold in the North America. They are generally not available for free. Standards Index (Standards by Division) - American Boat and Yacht Council https://abycinc.org/page/CopyofStandardsInd

    H-1 Field of Vision From The Helm Position
    Purpose:
    This standard is a guide to minimize obstructions in the field of vision from the helm station(s).

    NOTES:
    1. In order for this standard to be effective the boat must be operated in a reasonable and prudent manner.
    2. Boats can be operated in a manner and at certain speeds causing trim and/or roll angles such that visionis obscured. A boat operator may experience some loss of vision from the helm position while operating at high trim angles during the transition between displacement and planning mode.
    3. This standard does not relieve the operator of the requirement to comply with the USCG Navigation Rules.
    4. Movable items such as persons, gear, and convertible tops are considered under the control of the boat operator and therefore are not obstructions to visibility for the purpose of this standard.
    Scope:
    This standard applies to all boats powered by machinery.
    EXCEPTION: Sailboats.
    Current Version: (2012)
    Archive Standards:(2010) (2006) (2000) 1988, 1985, 1974, 1970, 1965 (Adopted)​
     
  6. fallguy
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    fallguy Senior Member

    We were at three lengths for me and my wife is shorter than me and rejected the setup. Basically, she said she couldn't drive the boat, so we need to get closer to the drawn plans. It is always the hope to build cabins high for tall people, but the front edge is at a settee; so relatively easy to lower the roofline without much realized penalty inside. I will also take the helm up 3 inches.
     
  7. fallguy
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    fallguy Senior Member

    Is this complete, or is the paid for version more extensive? It doesn't seem to say much as is. I would like to understand their standards for railings as well. I was not planning railings forward of the cockpit as we are about 3 feet away from the edge to walk to the trampoline, but during my paint prep, I nearly went down face first onto concrete and was near an area with a storage locker, so have decided to install a short lifeline. Short as in about 14" off the deck. If I go higher; it will look odd as that is 36" above the cockpit and a simple extension of the cockpit railing that will transition to cable. And people are walking 3 feet away. Anyhow, not meaning to drift, but understand if buying their standards is more than your citation is all.
     
  8. gonzo
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    gonzo Senior Member

    Backing into the slip is for easier boarding. Most boats have an aft cockpit and a swim platform with a transom door.
     
  9. DCockey
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    DCockey Senior Member

    What I posted above is not the H-1 standard. It is a description of what is included in the standard which I copied from the ABYC website (link posted).
    Rails are covered by ABYC H-41
    H-41 Reboarding Means, Ladders, Handholds, Rails and Lifelines
    Purpose: This standard is a guide for the design, construction, and installation of reboarding means, ladders, handhold devices, grab rails, rails, lifelines, and slip resistant surfaces.

    Scope: This standard applies to all boats.

    EXCEPTIONS:
    1. Manually propelled boats
    2. Aquatic toys
    3. Canoes, kayaks, or other boats with a beam less than 3.6 ft (1.1m).
    Current Version: (2014)
    Archive Standards: (2009) (2006) (1998)
    To obtain the ABYC standards you need to an ABYC member and/or pay ABYC.
    ABYC Standards - American Boat and Yacht Council https://abycinc.org/store/ListProducts.aspx?catid=189634
    ABYC Membership - American Boat and Yacht Council https://abycinc.org/page/membership
     
  10. fallguy
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    fallguy Senior Member

    ahh!

    it will be similar
    ouch, $500 to get rail recommendations for a single vessel?
     
  11. DCockey
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    DCockey Senior Member

    Or join ABYC for $275/year and have online access to the standards. :)
     

  12. fallguy
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    fallguy Senior Member

    Well, we modified things and are estimating 68 feet versus a calculation of 76 feet versus a prior calculation, before modifications of 97 feet blind in front. Any further adjustments are really going to damage cabin spaces for incremental gains only of say 5 feet.

    A better solution will be to place a 8" higher step to the right of the helmsman's standing area, so the operator can perch a bit during docking.

    Thanks to everyone. I did go away from Wood's a bit here as we are a taller family and want to be able to not have too many neck breakers onboard.

    The helm has very good 360 vision with the exception of the blind area in front. I am going to try to make the bench higher, so might need to make a way to boost up into it so when seated you are not lower or perhaps an inch higher than when standing.

    Again, thanks for the responses.
     
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