Ship Handling Flashcards
Where is the vessels pivot point when stopped in calm conditions?
CG approx midships
Where is the ships pivot point when making headway?
Roughly 1/4 length from forward
Where is the ships pivot point when making sternway?
Roughly 1/4 length from astern
What’s the advantage/disadvantage of FPP?
- Advantage: Less prone to mechanical failure and efficent at constant speeds
- Disadvantage: Limited maneuverability espically at low speeds/astern. The pitch of the propeller is fixed which can result in higher fuel consumption
What are the advantages/disadvantages of CPP
Advantages:
* Superior maneuverability
* Fuel efficiency via controlling the pitch
* Better in emergencies due to its ability to go from full ahead to full astern
Disadvantages:
* Higher maintenance requirements and liklihood of mechanical failure
How to turn the vessel quickly whilst in confined waters?
Turn Short Round
1. Dead slow ahead - Hard to starboard
2. After approx 45° return to amidships and move astern
3. After approx 120° Put helm to starboard and move slow ahead
What is your understanding of squat?
Water always flows around and under the vessel but when the flow beneath a vessel is restricted by a small UKC it increases velocity and decreases pressure causing the vessel to sink
What are some indications of squat?
- Unusual noise or vibration
- Sluggish steering
- Unusual trim
- large stern/bow wave
What is your understanding of shallow water effect?
A build up of water ahead of the ship forces water under the bow at a higher speed creating low pressure that causes the ship to squat by the bow (bow sinkage)
How should the vessel be manoeuvred for pilot boarding?
- Speed adjusted in accordance with advice from port or VTS
- Heading adjusted to create a lee for the pilot boat
- Wind usually positioned between bow and quarter on one side to create an area of calm water on the other side
