Ship to ship interaction

Question 1

What happens when two vessels meet (pressure)(3)?

Answer 1

• Combined positive bow pressures encourage the respective bows to be repelled away
• The bows now come under the influence of the other vessel’s stern and are drawn towards it to equalise pressure.
• As the vessels draw clear, combined low-pressure zones exert a greater turning force and cause the sterns to be drawn towards each other

Question 2

What forces will act upon one another when a vessel overtakes?

Answer 2

Forward pressure zone of the overtaking vessel will act upon the stern of the vessel being overtaken.
Pressure zones will want to equalise so the overtaking vessel is drawn up on the other vessel’s stern.

Question 3

What will happen when two vessels are abeam (pressure zones)?

Answer 3

Bows are abeam, so powerful positive pressure zones from both vessels will cause the bows to ‘fall off’

Question 4

What will happen when a vessel is drawing clear after overtaking (pressure)?

Answer 4

Forward pressure zone of the overtaken vessel will act upon the low-pressure zone of the stern of the overtaking vessel. This can cause them to be drawn together.

Question 5

What does slower speed equal (2)?

Answer 5

• Less squat
• Smaller pressure zones

Question 6

What does change of trim equal?

Answer 6

Change in helm response