Sailed4seas的部落格

Ex 05-04

Ownship speed is 20.0 Knots and course is 245.4 degrees at beginning. 
The situational awareness is:
•    With three minutes vector length in 20.0 Knots, this vector is about 10 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 slower speed. (skill by comparing vector length)
•    Ownship have one crossing vessel at port side (green circle), distance unknown. (sighted)
•    Two overtaken vessels at port side slower than ownship. (skill by comparing vector length)
 
The situational awareness with 6 minutes speed vector is:
•    There are 6 vessels inside the collision square (Orange square). (sighted)
•    There is no time to remember what vessel is ahead or behind, what vessel is on starboard side or port side? (suspect)
•    Ownship now knows that “It is Collision area to be avoided, not the vessels”(statement) 
•    Where to go for ownship? (suspect)
•    To starboard side, One port side crossing vessel (green circle) will be at ownship starboard bow after 6 minutes which block ownship way to starboard side. ( sighted) 
•    To port side, two starboard side crossing vessel (red circle) will be at ownship bow after 6 minutes which will block ownship way to port side. ( sighted)
•    To make a 360 degrees turn, many vessels inside the traffic lane. (sighted) 
•    Ownship has the option to reduce speed as fast as possible to arrive collision square later. (suspect)
 
After 1 minutes 30 seconds exercise time lapsed:
Ownship speed is 16.0 knots which decreased from 20.0 kts with engine output reduced to 75% from beginning. 
Ownship course had altered 1 degrees port side to 244.6 degrees from 245.4 degrees with rudder “Port 10 “”starboard 10” in last 2 minutes. 
The situational awareness in 3 minutes speed vector is:
•    Ownship reduced speed once with less engine output 75%. (sighted)
•    Speed reduces 4.0 knots over 1.5 minute’s time. (sighted with reducing rate of 2.6 knots per minutes)
•    Overall situation looks good in this three minutes speed vector. (sighted)

The situational awareness in 6 minutes speed vector is:
 

• Two crossing vessels at starboard side are about to pass after 5 minutes (red circle).  (sighted)
• One crossing vessels at port side is about to pass after 4 minutes (yellow circle).  (sighted)
• Ownship will arrive collision square after 6 minutes. (sighted)
• Ownship have one minute time lapse to collision point. (skill)
• One minute time lapse is not enough. By ownship speed 16 knots now, one minutes run is 493.8 meters. (skill by experience)
• One overtaking vessel is at starboard quarter faster than ownship. (skill by comparison)
• Port side overtaken vessel ahead of ownship is OK now. (skill by comparing speed vector length)

After 3 minutes 00 seconds exercise time lapsed:
Ownship speed is 15.2 knots which decreased from 16.0, 20.0 kts with engine output reduced to 75% from beginning. 
Ownship course had steady on 244.9 degrees from 245.4 degrees with rudder “Port 10 “”starboard 10” at times. 
The situational awareness in 3 minutes speed vector is:
•    Ownship reduced speed once with less engine output 75%. (sighted)
•    Speed reduces 0.8 knots over 1.5 minute’s time. (sighted with reducing rate of 0.53 knots per minutes)
•    Overall situation looks good in this three minutes speed vector. (sighted)

• Only one crossing vessel from starboard side arrive collision point very close to ownship. (red circle) (sighted)

After 4 minutes 30 seconds exercise time lapsed:
Ownship speed is 14.2 knots which decreased from 15.2, 16.0, 20.0 kts with engine output reduced to 75% from beginning and further reduced to 23% from 30 seconds ago. 
Ownship course had steady on 244.2 degrees from 245.4 degrees with rudder “Port 10 “”starboard 10” at times. 
The situational awareness in 3 minutes speed vector is:
•    Ownship reduced speed twice with engine output 75% from the beginning and 23% 30 seconds ago. (sighted)
•    Speed reduces 1.0 knots over 1.5 minute’s time. (sighted with reducing rate of 0.7 knots per minutes)
•    Overall situation looks good in this three minutes speed vector. (sighted)

• One crossing vessel from starboard side will pass after three minutes. (red circle) (sighted)

Ownship had controlled heading change very carefully, but speed reduction is not decisive.

End od Ex 05-04