Towing Practice Questions

1. For the purpose of the towing light rules, the 'length of the tow' is measured from the:

• A.Stern of the towing vessel to the after end of the tow✓
• B.Bow of the towing vessel to the bow of the first barge
• C.Bridge of the towing vessel to the middle of the tow
• D.Waterline to the highest point of the deck cargo

Why: Length of tow is measured from the stern of the towing vessel to the after end of the tow. It is the trigger for the 200-meter threshold that adds a third masthead light and the diamond day shape.

2. While towing in a narrow channel, the towing vessel's posting of a proper lookout is:

• A.Optional if radar is operating
• B.Required only at night
• C.Always required, by sight and hearing and by all available means✓
• D.The responsibility of the towed barge's crew

Why: Rule 5 requires every vessel to maintain a proper lookout by sight and hearing as well as by all available means at all times. Radar supplements but does not replace a posted lookout, and the duty rests with the towing vessel.

3. A nylon tow hawser under heavy load suddenly parts. The PRIMARY danger to crew from the recoil is caused by:

• A.The weight of the wet rope as it swings across the deck
• B.The large amount of elastic energy stored in the stretched nylon, released instantly as a high-velocity snap-back✓
• C.Torsional spin of the rope as the twist in the laid construction unwinds
• D.The whipping action of the free end as it rapidly exits the tow bitt

Why: Nylon can stretch 30–40% under towing loads, storing an enormous amount of elastic (potential) energy. When the hawser parts, this energy is released instantaneously, propelling the recoiling end at lethal velocity across the deck — the 'snap-back zone.' This is far more dangerous than the weight or spin of the rope and is the leading cause of towing fatalities.

4. Which technique is MOST effective at reducing surge loads on the towline when towing in a following sea?

• A.Increasing speed to stay ahead of the waves
• B.Shortening the towline to keep the tow close under control
• C.Adjusting towline length so tug and tow are in phase with the wave pattern, and/or adding a heavy pennant or chain for catenary✓
• D.Attaching a sea anchor to the tow to slow it down

Why: In following seas, surge loads are greatest when the tow outruns the tug on wave faces. Adjusting towline length to keep tug and tow in phase (both on crests simultaneously) and adding catenary weight (chain pennant) are the most effective surge reduction techniques, as catenary provides a mechanical spring effect.

5. A barge with negligible GM (near-zero) that is initially upright may be in a condition of:

• A.Neutral equilibrium, where any small disturbance will cause a permanent heel with no tendency to return to upright✓
• B.Stable equilibrium because G equals M
• C.Unstable equilibrium only if G is above the keel
• D.Positive stability because GM cannot be negative when the vessel is upright

Why: When GM = 0, the vessel is in neutral equilibrium. Any external force will produce a permanent heel and the vessel will not return to upright on its own. This condition is dangerous in towing because wave or wind action can produce a permanent list that progressively worsens.