SABOT

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SABOT

• Standardized Auxiliary Boat Operations Training
• Ninth District - Eastern Region
• COMO. Lew Wargo, Sr.
• CQEC-9ER
• 02 APR 2015
• GENERAL TOWING

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SABOT

• GENERAL TOWING

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REFERENCES

• Coast Guard Addendum to the National Search and
  Rescue Manual (NSS), COMDTINST M16130.2(series)
• Auxiliary Operations Policy Manual
• COMDTINST M16798.3 (series)

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REFERENCES

• Boat Crew Seamanship Manual,
• COMDTINST M16114.5(series)
• Chapter 17
• Auxiliary Boat Crew Qualification Guide,
• COMDTINST M16794.52(series)
• SABOT Job Aid (Section H)

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GENERAL

• A. Do a complete RISK ASSESSMENT with the crew
  before undertaking any towing evolution.
• B. Communicate with the towed vessels crew who
  may have important information necessary to
  complete a successful mission

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GENERAL

• C. Should I Tow?
• What is the WX condition?
• What is the gross tonnage?
• Am I experienced to tow in the conditions?
• Will the vessels casualty effect towing?
• Is the construction of the D/V sound?

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GENERAL

• What is the number of POB on the D/V?
• Should all or some of the POBs be removed?
• How does the vessel ride in the sea conditions
  you may encounter?
• Are all POBs wearing PFDs?
• Has the operator every been towed by the Coast
  Guard before and how was it done?

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GENERAL

• Does the D/V have the proper fittings for towing?
• Is the D/V capable of emergency signals to
  attract your attention in the event of radio
  failure?

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GENERAL

• D. Caution
• Do not let a preceived need to engage in a
  towing mission override a complete, honest Risk
  Assessment process that emphasizes personal
  safety.

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GENERAL

• E. Change The dynamics of a towing
• situation continuously change from the
• time pre-towing preparations begin until
• mooring at the conclusion of the mission.
• Think ahead, what could change and how
• would you handle the change?

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GENERAL

• F. Training Realistic towing training based on
  standardized techniques, critical analysis, and
  mission debrief will contribute to risk
  management and the development of a towing risk
  management plan.

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FORCES IN TOWING

• STATIC FORCE
• A. Inertia The tendency of a vessel at
• rest to stay at rest. The more mass
• (displacement) a vessel has the more
• inertia it has and the harder it is to get it
• moving.

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FORCES IN TOWING

• B. Moment of Inertia Occurs when a towed vessel
  resists turning to change heading. The larger the
  vessel, the more resistance there will be in
  turning. Unless necessary due to immediate
  danger, DO NOT attempt to start towing ahead and
  change direction at the same time. Start slowly
  on the initial heading of the tow if possible.

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FORCES IN TOWING

• C. Caution When towing vessels of equal or
  greater mass, the capacity and capability of the
  towboat will be strained. This requires slow and
  gradual changes of speed and direction. Attempt
  to start towing on the initial heading to
  gradually overcome the tows inertia. Even when
  underway, the tow will resist turning.

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FORCES IN TOWING

• DYNAMIC FORCES
• Dynamic forces occur once the towed vessel is
  moving. They are based on the towed vessels
  characteristics (shape, displacement,
  arrangement, and rigging), the motion caused by
  the towing vessel, and the effects of waves and
  wind.

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FORCES IN TOWING

• Momentum
• Once a vessel moves in a straight line, it wants
• to keep moving in a straight line.
• B. Angular Momentum
• Once the towed vessels heading begins to
• change, it wants to keep changing in the same
• direction.

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FORCES IN TOWING

• D. Frictional Resistance
• As a vessel moves, the water in contact with
  the hull moves as it is dragged. The greater the
  under-water area of the vessel the greater the
  frictional resistance. This keeps a steady
  tension in the towing rig and is managed by
  speed. Higher speeds cause higher friction and
  more strain.

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FORCES IN TOWING

• Form Drag
• The size and shape of a towed vessel can
  help or hinder. A deep draft vessel takes more
  effort to change direction than a fine, shallow
  (planning) hull. Deep draft towed vessels may be
  able to help offset form drag by using its
  rudder.

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FORCES IN TOWING

• Wave Making Resistance
• A surface wave forms at the bow while the
  hull moves through the water. The size of the bow
  wave increases as speed increases and generates
  resistance to movement of the boat.

CAUTION Do not tow any vessel above its hull
speed.
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FORCES IN TOWING

• G. Wave Drag
• Depends on the wetted surface area of the hull
  and the amount of freeboard exposed to wave
  action. In heavy seas this can cause the tow to
  stop and transfer a heavy strain to tow rig. In
  head seas the towing vessel can control this with
  speed and angle. In following seas speed up and
  slow down to keep tension on towline.

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FORCES IN TOWING

• H. Spray drag
• Provides resistance to the tow increasing
  shock load.
• Wind Drag
• Can cause shock loading and have a bad
  effect on the towed vessels motion and
  stability.

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FORCES IN TOWING

• J. Buoyancy Response Gravity Effects
• A towed vessels bow may react to a wave by
  pitching up, or by sub-marining. Buoyancy
  response to following seas may cause tow to yaw
  or gravity may cause it to gain speed and surf
  down the face of a wave. Once making way, a
  vessels buoyancy response or the effect of
  gravity may cause severe shock-loading.

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FORCES IN TOWING

• K. Combination of Forces Shock-Load
• Rarely do you deal with only one force
  acting on a tow. Shock-loading may cause severe
  damage to both vessels and overload a tow rig to
  the point of failure. It may also cause momentary
  loss of directional control by either vessel and
  could capsize smaller vessels.

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FORCES IN TOWING

• TO COUNTER-ACT SHOCK LOADING
• Place vessel In-Step
• Lengthen the towline
• Change course
• Deploy drogue
• Reduce towing speed
• Adjust towing speed

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FORCES IN TOWING

• COMBINATION OF FORCES
• Inertia Momentum
• Form Drag Wave Drag
• Wind Drag
• Movement of Inertia
• Angular Momentum
• Frictional Resistance
• Wave Resistance

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FORCES IN TOWING

• Shock-Loading dangers
• 1. It can cause damage to tow rig and
• fittings.
• 2. It can break the towline and cause
  Snap-back!
• 3. Can swamp or capsize the tow.

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TOWING EQUIPMENT

• A. Towline Have faked out on deck or otherwise
  ready for easy deployment.
• Regularly inspect for cuts, chaffing, flattening
  (from excessive loading), fusing (from excessive
  loads), or snags
• IF ANY OF THE ABOVE DO NOT USE The tow rig is
  only as strong as its weakest link! (If a tow
  rig uses a ¾ nylon towline with a 1 ton rated
  shackle, the tow rig is limited to 1 ton!)
• Have towline faked out and ready for easy
  deployment, see next slide

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FAKED LINE
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TOWING EQUIPMENT

• B. Pendant A short length
• of towline used between
• the towed vessel and
• towline. It is used to
• prevent wear on the
• towline. This could be 1/2
• of a bridle.

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TOWING EQUIPMENT

• C. Bridles Inspect regularly with towline.
• 1. Use Y bridle when both legs can be
• rigged to exert an equal pull on the
• hull.
• 2. Should be long enough to clear all
• obstructions on the deck and meet
• forward of the bow.

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TOWING BRIDLE
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TOWING EQUIPMENT

• 3. Keep the bridle legs long enough to keep the
  angle of the legs under 30 degrees.
• 4. The legs must be long enough to reduce the
  towed vessels yaw.
• 5. Protect with chaffing gear as necessary.
• 6. Used to center tow behind towboat and/or to
  clear obstructions on stern of towboat.

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TOWING EQUIPMENT

• D. Heaving lines
• Light weight,75 to 100 feet long.
• Cotton line works well (wet before using)
• The end should be lightly weighted for
• throwing.
• Suggest having more than one
• Attach a small snap on the standing end for
• quick attachment to the tow rig.

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TOWING EQUIPMENT

• Heaving line and ball
• Float Line
• Always yell HEADS UP before throwing
• Always throw over the target (BOAT)

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TOWING EQUIPMENT

• G. Dock lines Have sufficient dock lines to
• moor your vessel while you have another
• vessel in an alongside tow.
• H. Fenders Have enough fenders to properly
  protect both vessels while in an alongside tow
  and for docking with the side tow. Use the
  largest size you can store. Have one large extra
  fender.

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TOWING EQUIPMENT

• Skiff Hook
• A snap hook that is used to attach a
  towline to the towing eye on smaller boats that
  do not have suitable deck cleats. The skiff hook
  attaches to the end of a pole (boat hook) for
  reaching the towing eye of a D/V. The towing eye
  is one of the strongest attachment points on a
  boat but is extremely hard to reach for
  connecting and disconnecting the towline.

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TOWING PROCEDURES

• Throughout the entire towing evolution,
• communications between the coxswain and
• crew is absolutely necessary for a Safe and
• efficient operation.

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TOWING PROCEDURES

• A. Notification Get as much information as
  possible/needed before getting underway. Assign
  this duty to one of the crew.
• Write all information down. Develop a full
  understanding of the situation.
• Make a conscious decision to Accept or Not
  Accept the mission.
• B. Brief the crew.

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TOWING PROCEDURES

• C. Evaluate the conditions with the crew.
• D. Navigate safely to the scene
• Operate at a safe speed at all times.
• Keep a constant awareness of position and area
  hazards.
• Stay aware of the distressed vessels position
  and condition.

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TOWING PROCEDURES

• E. Communications with D/V
• 1. Keep in radio contact on a regular basis and
  give an ETA.
• 2. Advise POBs on D/V to don PFDs.
• 3. Get details of D/Vs deck layout
• 4. Ask for any important information.
• 5. Determine if anything has changed.

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TOWING PROCEDURES

• 6. Ascertain any sense of heightened urgency.
• 7. Inform the D/V that once on scene you will
  observe conditions and make final preparations
  before setting the tow.

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TOWING PROCEDURES

• NOTE
• Once on scene dont allow D/V to become
  endangered while waiting for POB to put on their
  PFDs. Take action to remove POBs from danger or
  from the D/V.

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TOWING PROCEDURES

• F. Perform On-Scene Assessment
• 1. Evaluate the location and any abnormal
  conditions of deck fittings.
• 2. Confirm the number of POBs.
• 3. Note any unusual conditions that
• would affect towing, (loose gear,
• rigging, etc.)

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TOWING PROCEDURES

• 4. Decide if you should place crew on D/V or
  remove any POBs from the D/V.
• 5. Decide whether to tow or not.
• 6. Do you need a bridle on the D/V?
• 7. Will a drogue be needed for the tow?
• 8. Brief both crews of intentions.

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TOWING PROCEDURES

• G. Determine the approach Crossing the T,
  parallel or back-down.
• H. Determine method for passing tow rig
• I. Brief both crews
• J. Determine the Danger Zone
• K. Determine the Maneuvering Zone
• L. Determine the Optimum Position

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Y BRIDLE ASTERN TOW
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Y BRIDLE ASTERN TOW
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SINGLE LEG ASTERN TOW
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SINGLE LEG ASTERN TOW
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SINGLE LEG ASTERN TOW
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V BRIDLE ASTERN TOW
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ASTERN TOWING

• Maneuver
• Your vessel so crew can maximize use of the
  
• best deck area for passing the tow
  rig.
• Bow or stern into the seas. This will provide
  the
• most vessel control and visibility for the
• coxswain, while station keeping a safe
• distance from the D/V.
• Plan a safe Escape Route for emergency.

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ASTERN TOWING

• B. Rough seas In rough seas make approach with
  bow or stern into the prevailing forces. (if it
  works in rough seas it will work in any seas)
• (NOTE IF THE SEAS ARE TOO HEAVY AND YOU ARE
  TAKING ON WATER OVER YOUR STERN, YOU ARE IN SEAS
  TOO ROUGH FOR YOU!)

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ASTERN TOWING

• C. Approach
• Make approach at the slowest speed possible while
  maintaining steerage.
• Stop in optimum position and pass the tow rig
  with a heaving line (At coxswains command).
• (Coxswain MUST let the crew know before making
  correcting maneuvers so that they can safely tend
  lines.)

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ASTERN TOWING

• D. Opening closing
• Use opening and closing maneuvers to maintain
• optimum position. Act before a problem
• develops.
• (NOTE) Maneuver as required but it is
• preferable not to maneuver when lines are
• over (except the heaving line).

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ASTERN TOWING

• Passing the tow rig
• (Include drogue if it is needed.) In calm
  conditions the rig may be passed by simply
  handing it over or by use of a boat hook.
• Practice using a heaving line for moderate or
  heavy seas.

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ASTERN TOWING

• 1. To pass the heaving line
• If cotton heaving line wet it to make it more
• flexible and to minimize tangling.
• Take 2/3 of the heaving line coil into the
• casting hand and the reminder in the other.
• Check if area is clear of obstructions.

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ASTERN TOWING

• Advise the coxswain when ready (I have a shot)
• Coxswain will give command Take your shot
• Call out to the D/V Heads up
• Cast so the heaving line falls across the D/Vs
  deck.
• Tell the coxswain when casting

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ASTERN TOWING

• If not successful, quickly retrieve the heaving
• line and prepare a second line or attempt.
• Repeat steps 2 through 7 until successful

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ASTERN TOWING

• 2. Keep coxswain advised on tow rig transfer
• a. TOW RIG AWAY
• b. TOW RIG IN THE WATER
• c. TOW RIG ON D/V
• d. TOW CONNECTED
• e. D/V CREW SECURED

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ASTERN TOWING

• F. Connecting the tow rig
• Monitor crew of D/V to follow directions
• Towline clear of any gear on deck
• Chaffing gear
• Under railing
• Not pulling against railing or stanchion

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ASTERN TOWING

• 2. Connect to cleat or the Towing Eye.
• If using the towing eye use extreme caution
• in bringing the vessels together. (Not safe to
• do in rough seas)
• If using deck fittings, be sure they are in
• good condition. Dont hesitate to put crew
• aboard to check out conditions.

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ASTERN TOWING

• 3. Have crew of D/V return to cockpit area after
  securing towline
• Slowly open distance between boats and manually
  adjust length of towline. (Crew and Coxswain
  should be in communication constantly during this
  process.)
• (Line in water, Tension coming on line,
  under tow)

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ASTERN TOWING

• Have your crew take a working turn on
• bitt/cleat before there is a strain on towline.
• After length is set (Maintain a catenary in tow
  rig) make up line on bitt/cleat.

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ASTERN TOWING

• Start tow slowly and if possible, in the
  direction the D/V is pointing.
• Set tow Watch and maintain COMMS with the D/V.
• C. Slowly bring tow onto desired heading
• Watch for YAWING or any other problems with
  the tow.

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ASTERN TOWING

• E. Maintain catenary while towing
• F. Keep tow in step and tow at safe speed
• G. If yawing
• straighten helm of D/V or, If O/B or I/O raise
  
• its lower unit or,
• adjust the trim on D/V (Move POBs) or,
  
• decrease speed or,
• change angle into waves or wind or,
• deploy a drogue from D/V.

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USE OF A DROGUE

• H. Drogues are used behind a tow to slow it
• down and give stability. It acts much like
• a parachute. Its deployed from the stern
• of the towed vessel. A traditional drogue is a
  
• canvas or a synthetic cloth cone open on
• both ends.

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USE OF A DROGUE

• With a short hawser and large swells on the
  stern, the drogue is deployed to prevent the tow
  from running up the stern of the towboat as it
  keeps tension on the towline preventing the tow
  from surfing down the face of a wave.

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USE OF A DROGUE

• The drogue should have about 200 feet of line
• (marked every 50 feet) attached to the bridle
• swivel using a shackle.
• Pass the drogue directly to the D/V and watch
• the crew ready the drogue rig. Use centerline
• attachments or bridle unless compensating for a
• jammed rudder.

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USE OF A DROGUE

• A second light line should be attached to the
  smaller end of the drogue for ease of drogue
  retrieval.
• Start the tow moving slowly, then deploy the
  drogue. Once it sets, increase speed while the
  towed vessels crew observe the rig.

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USE OF A DROGUE

• To avoid fouling drogue lines
• Slow or stop the tow and have the towed vessel
  recover the drogue.
• Run a dumping line from the drogue to the
  stern of the towed vessel (suitable for large
  drogues that drain slowly).

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ASTERN TOWING

• I. Shortening the tow
• 1. Select a safe area
• 2. Brief both crews on planned action.
• 3. Determine new towline length
• 4. Reduce speed and take off way slowly
• 5. Break towline from bitt/cleat

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ASTERN TOWING

• 6. Back as crew keeps line out of screws
• 7. When at desired length, make up line on
  bitt/cleat
• 8. Resume tow in direction of D/V heading

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ALONGSIDE TOW

• Always do in calm protected waters.
• Determine which side to tow from
• Consider side of dockage
• Consider your visibility
• Consider location of fittings on each vessel
• Consider the type of approach (free or back-
• down)
• Consider which vessel will be against the dock.

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BACK-DOWN
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FREE APPROACH
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ALONGSIDE TOW

• B. Prepare alongside tow lines
• C. Position fenders to protect both boats
• D. Prepare dock lines and have boat hooks ready
• E. Note direction of wind and current and
  consider their effect on mooring
• F. Always connect Line 1 first then 2.

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ALONGSIDE TOW

• G. If necessary you can then start towing in a
• forward direction only.
• H. Connect line 3 and then 4 if used.
• I. Adjust fender position or use a Walking
  fender as necessary.

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ALONGSIDE TOW

• Tighten lines as follows
• While going forward and turning away from the
  tow, tighten lines 3 and/or 4.
• Go in reverse to tighten lines 1 and 2 or
• while in forward turn into the tow.

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ALONGSIDE TOW

• CAUTION Keep all body parts out from between
  boats.
• Always place the eye of a line on the D/V so that
  adjustments can easily be made from towing boat.
• You may have to place crew aboard the D/V as a
  lookout

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ALONGSIDE TOW
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4 LINE ALONGSIDE TOW
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3 LINE ALONGSIDE TOW
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MOORING ALONGSIDE TOW

• A. It is easier to moor into the prevailing
  force and on the lee side of dock.
• B. Use only enough speed for steerage
• C. Use a lookout to call range and bearing to
  dock and objects or other traffic.

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MOORING ALONGSIDE TOW

• D. It is easier to turn toward the tow in
• forward. To make a turn away from the
• tow consider going in reverse. You can
• make a very sharp turn in reverse.
• E. If possible, place the larger of the two
  vessels against the dock.
• F. Secure D/V to the dock

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MOORING ALONGSIDE TOW

• G. Gather required information for reports.
• H. Break tow
• I. Report Tow secure per local policy.
• J. Get underway

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TOWING PRECAUTIONS

• A. Have all POBs on D/V don PFDs. Furnish if
  necessary. Dont jeopardize POB or vessel
  safety waiting for POBs to don PFDs.
• B. Remove POBs when necessary
• C. Cast heaving lines well over D/V so line
  falls across D/Vs deck.
• D. Monitor conditions of the tow rig.

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TOWING PRECAUTIONS

• E. Establish and maintain D/V COMMS
• F. Monitor any sea-water on D/V
• G. Monitor conditions of POBs on D/V
• H. Keep clear of tow rig (SNAP-BACK)
• I. Keep tow rig attachment points low and
• near the centerline

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TOWING PRECAUTIONS

• J. Do not attach tow rig to lifeline,
• stanchions, grab rails, or ladders.
• K. Do not attach lines to cleats that are
• only held by screws.
• L. Avoid using lines provided by the D/V
• M. Avoid using knots to join tow-lines
• N. Use two crew if possible to tend lines

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TOWING PRECAUTIONS

• O. Tend a towline by hand until secured to D/V
  then secure on coxswains command.
• P. Only use figure-eight cleat hitches on
  cleats with NO weather hitch.
• Q. Crew should keep clear of towline.

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TOWING PRECAUTIONS

• R. Crew should not cross arms but change hands
  when handling lines.
• S. Keep towline clear of prop and rudder.
• T. Use chaffing gear as needed.
• U. Avoid towing boats over 50 larger.
• V. Tow at a safe speed for conditions.
• W. Avoid sudden maneuvers.

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TOWING PRECAUTIONS

• X. Consider a drogue to reduce yaw.
• Y. Have helm of D/V manned and have D/V steer at
  stern of towboat if needed.

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TOWING PRECAUTIONS

• Z. Keep towed boat in trim, consider
• 1. Condition of D/V (damage, taking on
  water, etc.)
• 2. Structural design of D/V
• 3. Cargo
• 4. Number and location of POBs

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TOWING PRECAUTIONS

• WARNING
• Overloading astern, or along either side of the
  centerline, may swamp or capsize a tow!

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TOWING PRECAUTIONS

• AA. Maintain a diligent tow watch. All
  crew should be assisting in this.
• AB. Bridle breaking strength should be
• equal to or greater than towline.
• AC. If possible, do GPS and chart work at
  dock

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TOWING PRECAUTIONS

• AD. If there is a possible need for a pump
• or drogue, pass before start of tow.
• AE. Coxswain/Crew should inspect the tow rig
• before it is connected.