Sailed4seas的部落格

 
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 01 minutes exercise time lapsed:
Ownship speed is 18.6 knots which decreased from 20.0 kts with engine output reduced twice 65% from beginning and further reduced to 35%. 
Ownship course had altered 2.6 degrees starboard side to 248.0 degrees from 245.4 degrees with rudder cycle from “starboard 10”and “Hard Port “in last minute. 
The situational awareness in 3 minutes speed vector is:
•    Ownship reduced speed step by step with less engine output 35%. (sighted)
•    Speed reduces 1.4 knots over one minute’s time. (sighted)
•    Overall situation is hard to tell in this three minutes speed vector. (sighted)
 
The situational awareness in 6 minutes speed vector is:
•    Ownship Speed reduces 1.4 knots is not enough? (sighted)
•    Course alternation is good for crossing vessels, all crossing vessel will pass after 6 minutes. (sighted)
•    Course alternation 2.6 degrees starboard side to 248.0 degrees is crossing overtaken vessel bow(sighted) 
•    Ownship speed is still too fast as ownship arrive collision square about the same time with crossing vessels. (sighted)
 
After 02 minutes exercise time lapsed:
Ownship speed is 16.5 knots which decreased from 20.0 kts with engine output reduced twice 65% from beginning and further reduced to 35% after 30 seconds. 
Ownship course had altered 0.9 degrees starboard side to 248.9 degrees from 248.0,  245.4 degrees with rudder cycle from “starboard 10”and “Hard Port “ and “ Starboard 30,20,5 …”. 
The situational awareness in 3 minutes speed vector is:
•    Ownship reduced speed step by step with less engine output 35%. (sighted)
•    Speed reduces 3.5 knots over two minute’s time. (sighted)
•    Overall situation looks good in this three minutes speed vector. (sighted)
•    All crossing vessels are about to pass ownship bow in next minute. (sighted)
•    Overtaking vessels are in proper distance away. (sighted)
 
The situational awareness in 6 minutes speed vector is:
•    Overall situation looks pretty mess in this 6 minutes speed vector. (sighted)
•    The moral is “You don’t need to use too long speed vector while vessels are plenty.”(rule)
•    Three minutes speed vector represent ownship collision risk with proper consideration in ship maneuvering. (rule)
  

After 03 minutes exercise time lapsed:
Ownship speed is 14.9knots which decreased from 16.5, 18.6, 20.0 kts with engine output reduced twice 65% from beginning and further reduced to 35% after 30 seconds. 
Ownship course had steady in  249.3 degrees from 248.9,  248.0,  245.4 degrees in last minutes. 
The situational awareness in 3 minutes speed vector is:
•    Ownship reduced speed step by step with less engine output 35%. (sighted)
•    Speed reduces 5.1 knots over three minute’s time. (sighted)

 Overall situation looks good in this three minutes speed vector. (sighted)
•    All crossing vessels are about to pass ownship bow in next 3 minute. (sighted)
•    Overtaking vessels are in proper distance away. (sighted)

After 04 minutes 09 seconds exercise time lapsed:
Ownship speed is 13.7 knots which decreased from 14.9, 16.5, 18.6, 20.0 kts with engine output reduced twice 65% from beginning and further reduced to 35% after 30 seconds. 
Ownship course had steady in  248.3 degrees from 248.9,  248.0,  245.4 degrees in 2 minutes. 
The situational awareness in 3 minutes speed vector is:
•    Ownship reduced speed step by step with less engine output 35%. (sighted)
•    Speed reduces 6.3 knots over 4 minute’s time. (sighted with speed reduction rate of 1.5 Knots per minute)

 Overall situation looks good in this three minutes speed vector. (sighted)
•    All crossing vessels are about to pass ownship bow in next 2 minute. (sighted)
•    Overtaking vessels has altered course to starboard side. (sighted)

The moral of this exercise is “ Once the situation seems impossible become much easier by speed reduction, especially for high speed vessel.”

End of Ex 05-01