You are docking a ship with a single-screw tug assisting on your starboard bow. How should the tug be tied up if you are anticipating that she will have to hold your bow off while you stem the current?
• Forces on a tug when holding a ship’s bow against current • Difference between head line, stern line, and spring line when a tug is made fast to a ship • How line lead (ahead or astern) affects the tug’s ability to push/pull and stay in position
• If the tug must hold the bow off while the ship stems the current, in which direction will the tug’s propulsion and the current be trying to move the tug? • Which type of line arrangement best resists fore‑and‑aft movement while allowing the tug to push sideways on the bow? • What are the risks if the tug is fast with only a single line when significant current is acting on the ship’s bow?
• Identify which line configuration provides fore‑and‑aft restraint as well as lateral pushing power for the tug • Check which choice gives the tug a safer, more secure lead for working in strong current at the ship’s bow • Eliminate any options that would leave the tug held by only one line in a strong current or with a line that does not control surge in the direction of expected forces
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