DWO Ship Handling 2 — Questions and Answers
Question 1: When maneuvering a single-screw vessel with a right-handed propeller in close quarters, the stern tends to swing to which side when going astern?
- Port
- Starboard (Correct answer)
- Directly aft
- The direction of rudder angle
Correct answer: Starboard
A right-handed propeller in reverse produces paddle-wheel effect that kicks the stern to starboard.
Question 2: What is the primary purpose of a 'spring line' when berthing a vessel?
- To hold the bow into the dock
- To prevent fore-and-aft movement along the pier (Correct answer)
- To keep the stern from swinging away
- To provide emergency towing capability
Correct answer: To prevent fore-and-aft movement along the pier
Spring lines run at an angle along the ship's length to prevent the vessel from moving forward or aft along the dock.
Question 3: The advance of a vessel is defined as the distance traveled in what direction during a turn?
- Perpendicular to the original course
- Along the original course heading (Correct answer)
- Along the new course heading
- Toward the pivot point
Correct answer: Along the original course heading
Advance is the distance a ship moves forward (along the original course direction) from the time the helm is put over until the new heading is reached.
Question 4: When a deeply loaded tanker requires more stopping distance than a light ship, this is primarily due to:
- Increased wind resistance
- Greater displacement and inertia (Correct answer)
- Deeper rudder immersion
- Reduced engine power output
Correct answer: Greater displacement and inertia
Greater displacement means more mass and momentum, requiring significantly more distance and time to stop.
Question 5: A vessel is said to be in 'irons' when it:
- Has lost engine power completely
- Is held stationary by opposing spring lines
- Has lost steerage way and cannot maneuver effectively (Correct answer)
- Is secured to a mooring buoy
Correct answer: Has lost steerage way and cannot maneuver effectively
A vessel in irons has lost enough speed that the rudder is ineffective and the ship cannot respond to helm commands.
Question 6: When coming alongside a dock in a strong current, the preferred approach angle is:
- Parallel to the dock with maximum speed
- Perpendicular to the dock at 90 degrees
- Into the current at a shallow angle (Correct answer)
- Downwind at 45 degrees
Correct answer: Into the current at a shallow angle
Approaching into the current at a shallow angle allows the current to help slow the vessel and control the rate of closing.
Question 7: What effect does shallow water have on a vessel's turning ability?
- It improves turning due to bottom suction
- It has no effect on turning
- It reduces turning efficiency and increases turning radius (Correct answer)
- It causes the bow to swing faster
Correct answer: It reduces turning efficiency and increases turning radius
In shallow water, squat and increased water resistance reduce rudder effectiveness, resulting in a larger turning circle.
DWO Ship Handling 2
When maneuvering a single-screw vessel with a right-handed propeller in close quarters, the stern tends to swing to which side when going astern?