Nautical Knoweldge_5_Ladders & Stages

Embed Size (px)

Citation preview

  • 8/12/2019 Nautical Knoweldge_5_Ladders & Stages

    1/9

    Nautical KnowledgeLadders and Stages 1DEC, 2002

    Contents

    Rigging Stages, Bosuns Chair, and Rope Ladders 3

    Introduction 3

    Rigging a stage 4

    Rigging a Bosuns chair 5

    Portable ladders 7

    Gangways 8

  • 8/12/2019 Nautical Knoweldge_5_Ladders & Stages

    2/9

    2 Nautical KnowledgeLadders and StagesDEC, 2002

  • 8/12/2019 Nautical Knoweldge_5_Ladders & Stages

    3/9

    Nautical KnowledgeLadders and Stages 3DEC, 2002

    Rigging Stages, Bosuns Chair, andRope Ladders

    IntroductionThis section is not about lifting weights, but about lifting people. If the rules

    in lifting weight had to be narrowed to one, it probably would be to keep out

    of the way of loads. But when the load is people, theycant do that.

    So stick to the safety rules! Practical and closely supervised training is

    required for such operations, so be familiar with the basics given here.

    There are various ways to rig staging for a vessels maintenance. On board

    any vessel there is little space to set up properscaffoldingandstaging, and

    also there will always be obstacles on deck to contend with that make it

    difficult to set up staging. So there will generally be a good chance that you

    will have to compromise or jury-rig the staging.

    The easiest way to rig staging on a vessel is to use simple scaffolding, whichcan only be set up one way because of the arranged lengths and clips etc.

    The most important thing to remember about setting scaffolding up is that

    the base must be level and sturdy.

    After you set up a sturdy base, build the scaffolding to the height you

    require, going a little bit higher so you can fit guard rails. Then, using rigged

    lines, pull the planking up and place it atop the scaffolding and tie it down

    with lashing cord. Ensure you have a good working platform. Also ensure

    you fit the guard rails, which should be just above waist level.

    Because most vessels will not have the deck space to allow you to do this,

    you will have to use other parts of the ship to support the planking. There

    are two ways to do this:

    Lash a plank between the port and starboard shrouds by letting it rest on top

    of a ratline (a rope step lashed between shrouds). Then lash it in place and

    put safety lines around the entire area.

    Put a plank onto part of the superstructure of the ship, and then take the

    other end to a ratline or shroud and lash it in place. Again, fit safety lines

    and lash the planks down.

  • 8/12/2019 Nautical Knoweldge_5_Ladders & Stages

    4/9

    4 Nautical KnowledgeLadders and StagesDEC, 2002

    Those are the two basic stagings you will use on a ship: there are others like

    the flying stage and suspended stage which are explained in your text, but

    the key point is that there is no set way to rig up staging on a vessel, because

    each vessel is different and each situation will have to be assessed to see

    which is the best way to support planking.

    Just remember that safety is the key, and the lashings and support lines mustbe made fast extremely well and secure.

    Rigging a stageThe practical handiest size line for a stage rope is 20mm. This is known as

    a gantline. It must be long enough to reach the waterline on the bight when

    working over the ships side. One method of securing the end of the stage

    is shown below.

    Figure 1

    In the above method the rope tail is made fast to the standing part after the

    hitch is completed, using a bowline. If the stage is extra long, it is advisable

    to rig a centre line to prevent sagging in the middle.

    The standing part should be reeved through a lizard, shackle or best of all a

    tail block to enable it to be lowered and adjusted by those working from the

    stage.

    Take two full turns of the hauling part around the end of the stage and one

    full turn around the horn as a means of lowering.

  • 8/12/2019 Nautical Knoweldge_5_Ladders & Stages

    5/9

    Nautical KnowledgeLadders and Stages 5DEC, 2002

    Precautions

    Check stage for defects.

    Inspect all lines and fittings.

    Correctly rig the stage.

    Load test the stage to four times the intended load.

    Gantlines must trail in the water to be used as lifelines.

    Stages should only be rigged over water.

    Do not use while underway.

    Always set down before raising and lowering.

    Rig a rope ladder for access.

    Be positively tended and have a life buoy available.

    Rigging a Bosuns chairIn most work done aloft a bosuns chair and gantline is used, the gantline is

    always attached to the chair by means of a double sheet bend with the end

    seized to the standing part (Figure 2). The gantline should be reeved through

    a tail block or lizard for ease of hauling and lowering oneself.

    How to make a lowering hitch while on a Bosuns chairA long bight of the hauling part is pulled through the strop of the chair,

    passed over the head and allowed to drop behind to the feet. It is then passed

    under the feet and brought to the front. The slack on the hauling part is

    pulled tight forming the hitch. When ready to lower, render slack on the

    hauling part through the hitch, which it will easily do.

    The practice of holding on with one hand and making the lowering hitch

    with the other hand is dangerous.

  • 8/12/2019 Nautical Knoweldge_5_Ladders & Stages

    6/9

    6 Nautical KnowledgeLadders and StagesDEC, 2002

    Figure 2:Bosuns chair

    Note: Grip with hand and seize both parts of the gantline together before

    making the lowering hitch.

    Precautions

    Check bosuns chair for defects.

    Inspect all lines and fittings.

    Corrrectly rig the gantline.

    Load test four to five times the intended load.

    When hauling aloft in a bosuns chair it should be done by hand.

  • 8/12/2019 Nautical Knoweldge_5_Ladders & Stages

    7/9

    Nautical KnowledgeLadders and Stages 7DEC, 2002

    Figure 3:Riding a stay

    When riding a stay ensure the bow of the shackle rides the stay not the pin.

    Always seize (mouse) the shackle pin. Wear a safety harness if more than

    two metres aloft.

    The person working aloft should make sure all tools have safety linesattached to the chair. A safety precaution while in the chair is to have a

    harness attached to the standing rigging of the vessel. This will stop you

    from swinging around when the ship moves about.

    You can also use somebody on deck to lower you when need, but it must be

    made clear that they must take caution and have a turn with the halyard

    around a pin or something sturdy. Also, it is recommended that you use a

    purchased bosuns chair rather than a home-made one!

    Portable laddersRope ladders/side ladders are used to access stages over the vessels side,

    over hatch coamings to access parts of a hold etc. They are light and handy

    ladders easily carried around the decks. The top of the ladder can be left

    with the rope ends whipped or a thimble can be used. This enables it to be

    shackled to a boom if necessary.

  • 8/12/2019 Nautical Knoweldge_5_Ladders & Stages

    8/9

    8 Nautical KnowledgeLadders and StagesDEC, 2002

    Figure 4

    GangwaysGangways are used for the movement of people from the ship to shore, or

    vice versa. Things you must consider are tide movement, surge, weight of

    the users, and the length, height and angle of the gangway.

    Most importantly, ensure that the gangway is firmly secured to the ship, so

    that it does not move on the deck and cannot fall away from the ship. The

    gangway should be on wheels and must be able to withstand a great deal of

    weight. You must also watch the rise and fall of the tide, because you will

    have to adjust the height of the gangway accordingly.

    A gangway must have a hand-rail that is waist-high and rigid. It should also

    have slats which go across the planking every 400cm or so, and the planking

    should have a non-skid surface.

    The lifting cables for the gangway should be inspected regularly and

    greased.

    All the different types of gangways must be fitted with a safety net that is

    attached at four points: two on the ship and two at the bottom of the

    gangway or dock wall. The net should be tight, made from a rope with aminimum thickness of 18 mm, and it should be a little lower in the middle

    section of the net than the outer edges.

  • 8/12/2019 Nautical Knoweldge_5_Ladders & Stages

    9/9

    Nautical KnowledgeLadders and Stages 9DEC, 2002

    Check your prog ress

    1 List the precautions for rigging a stage.

    _____________________________________________________________________

    _____________________________________________________________________

    _____________________________________________________________________

    _____________________________________________________________________

    _____________________________________________________________________

    _____________________________________________________________________

    _____________________________________________________________________

    _____________________________________________________________________

    2 Briefly list safety precautions for working in a bosuns chair.

    _____________________________________________________________________

    _____________________________________________________________________

    _____________________________________________________________________

    _____________________________________________________________________

    _____________________________________________________________________

    _____________________________________________________________________

    _____________________________________________________________________

    _____________________________________________________________________

    Check your answers with those given at the end of this learning resource.