Sailed4seas的部落格

Ex 04-04

Ownship speed is 18.6 Knots and course is 063.8 degrees at beginning. ​

The situational awareness is:

• With three minutes vector length in 18.6 Knots, this vector is about 9 cables distance as above. (skill by knowing  three minutes run)
• Ownship have two crossing vessel at starboard side (red circle), distance unknown. (sighted)
• One overtaken vessel at starboard side has same speed as ownship. (skill by comparing vector length)
• Ownship have three crossing vessel at port side (yellow circle), distance unknown. (sighted)
• One overtaken vessel at port side slower than ownship. (skill by comparing vector length)

The situational awareness with 6 minutes speed vector is:

• One port side crossing vessel will be at ownship bow after three minutes. ( skill by observing target vessel speed vector touched our heading at three minutes (yellow square))
• One starboard side crossing vessel will be at ownship bow after 4 minutes. ( skill by observing target vessel speed vector touched our heading at 4 minutes)

The situational awareness with 9 minutes speed vector is:

• Ownship have one collision point with crossing vessel at starboard side (Red Square), after 7.5 minutes or so. (sighted)
• Another crossing starboard side vessel has no collision risk as 9 minutes speed vector has no collision point. (sighted)
• One crossing vessel at port side will be at ownship bow after 7.0 minutes or so (Pink Square). (sighted)

Overall situation awareness is:

• Ownship have to take care of three vessels around but no collision risk right now.(action)
• Ownship has to give way (avoid arriving red square area at same time with target vessel)  if starboard crossing vessel keeps current speed and course.(action)
• Does Port side crossing vessel keep his course after crossed separation line? (suspect)
• Forget other slower vessels, it is no harm can be done.(suspect)

After 02 minutes exercise time lapsed:

Ownship speed is 15.3 knots which had decreased from 18.0 kts with engine output 60% from beginning and further educed to 16%.

Ownship course had altered 4 degrees 067.1 degrees from 063.8 degrees with rudder angle “starboard 10” now.

The situational awareness is:

• Ownship reduced speed with less engine output just now. (sighted)
• Port side crossing vessel is about to pass after one minute (orange circle). (knowing what time to pass is skill)
• One overtaking vessel at starboard side is about to pass after 1.5 minutes (green circle). (skill by judging the collision point in target vessel speed vector position.)
• In this case, collision point in target vessel speed vector position in middle of its three minutes vector. (sighted)
• Crossing vessel at starboard side will pass after 4 minutes (red circle). (skill by estimating 3 minutes vector)
• One overtaken vessel at port side is still slower than ownship. (skill by comparing vector length)
• One crossing vessel at port side will pass ownship bow after 5 minutes (yellow circle). (skill by estimating speed vector direction)

What time target will pass ownship bow depends on target vessel speed vector; not depends on ownship speed. (Statement)

After 03 minutes 30 seconds exercise time lapsed:

Ownship speed is 13.2 knots which had decreased from 15.3, 18.0 kts with engine output 60% from beginning and further educed to 16% and 0 %.

Ownship course had altered 3 degrees 069.9 degrees to starboard side from 067.1,  063.8 degrees. Ownship had used “Hard Port” rudder to stop the starboard side turning rate in last minute.

The situational awareness is:

• Ownship reduced speed with 0% engine output since 1.5 minute before. (sighted)
• Port side crossing vessel passed (orange circle). (sighted)
• Overtaking vessel at starboard side passed (green circle). (sighted)
• Crossing vessel at starboard side will pass after 2.5 minutes (red circle). (skill by estimating 3 minutes vector)
• One crossing vessel at port side will pass ownship bow after 4.5 minutes (yellow circle). (skill by estimating speed vector direction)

After 05 minutes 00 seconds exercise time lapsed:

Ownship speed is 11.1 knots which had decreased from 13.2, 15.3, 18.0 kts with engine output 60% from beginning and further educed to 16% and 0 %.

Ownship course is steady in 069.9 degrees to starboard side from 067.1,  063.8 degrees.

The situational awareness is:

• Ownship reduced speed to 0% engine output. (sighted)
• Speed reduction is slowly although all engine output is 0%. (rule)
• Port side crossing vessel passed (orange square). (sighted)
• Overtaking vessel at starboard side passed (green square). (sighed)
• Crossing vessel at starboard side will pass after one minute (red circle). (skill by estimating 3 minutes vector)
• One crossing vessel at port side will pass ownship bow after 3 minutes (yellow circle). (skill by estimating speed vector direction)

After 06 minutes 23 seconds exercise time lapsed:

Ownship speed is 9.6 knots which had decreased from 11.1, 13.2, 15.3, 18.0 kts with engine output educed to 10 % three minutes.

Ownship course is steady in 069.9 degrees for 3 minutes with trouble to keep the heading.

The situational awareness is:

• Ownship try to alter course to port side with “Hard Port” for one minute. (sighted)
• With no effect of turning, ownship increased engine output. (sighted)
• With slower ownship speed 9.6 Knot, “Hard Port” rudder will be effective after longer time. (statement)
• One minute is the time needed for rudder order to take effect. (rule)
• All vessel with color square passed. (sighted)
• One crossing vessel at port side will pass ownship bow after one minute (yellow circle). (sighted)
• This crossing vessel has no collision risk. (skill by knowing collision line has no crossing)

End of Exercise 04-04