Sailed4seas的部落格

Ex 01-04

What awareness ownship can have in this Radar Picture?

After 6 minutes 11 seconds exercise time, Let's look at the first part: safe speed.

• Vessel passed precautionary area with 28 knots. This means that Own Ship  has increased speed, 19.2 to 28.0 Knots. (Sighed: what a foolish thing to do) 
• All Crossing traffics (crossing vessels) are left behind.  (sense) 
• Ownship collision line (three minutes speed vector line) crossed with Pilot Boat in 0.5 minutes run.   (sense) 
• "Pilot Boat”    already altered course to 100  degrees.  (sense) 
• "Pilot Boat”   speed is slower than Ownship.  (skill by compare the length of speed vector by a divider beside monitor.)
• If you have the habit to remember the Target Vessel speed, in this case "Pilot Boat"   is 16 knots speed.  Ownship is 12 knots faster than her. (sense) 
• Ownship collision risk with “Pilot Boat” is nothing as long as she is slower than ownship.  (ownship is passing  Pilot boat now)
• Ownship is on original course 065 degrees now. Rudder angle used are plenty. (sense) 
• Ownship   Used   "Hard starboard" and "Hard port" rudder order in the first minute with no  actual vessel track had changed . (sense) 
• These rudder orders used for only one reason: Anxiety comes when ownship under pressure without knowing any collision risk involved.    (sense)

In this exercise ownship has only one thing in mind: to change course but forget to reduce speed.  This concept is carried from our OOW times.

In open sea; avoidance maneuvering always conducts with plenty sea room, give passing vessel wide berth is the moral which were written on “Standing Order”and “Night Order Book”book all the times. Every OOW have to sign his acknowledgement by his initial each time these words appeared on Order Book. There is nothing wrong with wide berth but in narrow strait or precautionary area:

In the narrow strait, give passing vessel wide berth is not applicable.

Rules in narrow strait are: Every vessel is immediately in close quarter situation once collision risk involved.  (sense)

• After 6 minutes, Ownship sailing track changed direction four times as green square showed in monitor. (sense) 

It is true that faster speed can save a little passing time but at the price of all collision risks (pressure) compiled in even shorter interval. (sense) This is working habit of some Master until he had a collision case. As wrong habit has exactly same effect as good habit to eliminate our awareness of danger. Even after he had first collision case after 24 years sea time at bridge, he is not aware what thing is actually go wrong.

It is the Speed caused Collision in Narrow Strait, not the course.  

In the BRM side:

• Frequent rudder orders make everybody on the bridge anxious.
• Visual techniques to verify collision risk by relative bearing need ownship steady on his heading. (This skill will discuss later).

If ownship has three collision points with three vessels ahead, Speed up cannot avoid any one of these collision points but compress these into less time span. Let's check this Picture before:

• Ownship involved collision risk with three vessels. (sensed)
• If Ownship original speed is 19.2 Knots, ownship will be in red vessel position. (sense)
• If ownship keep original speed, ownship will have two collision points with two crossing vessels (Mobil 1 in orange color and container vessel outbound in red color).  (sense)
• If ownship increase speed to yellow vessel position, all three crossing vessels will have three collision points with ownship. (sense)
• More speed, more collision risks. ( is not a statement, it is a golden rule. See for yourself.)
• No Speed, No collision risk. (almost) 
• Any uncertainty, stop the engine immediately. (sense)
• While all ships are working against you (have collision risk), just reduce the speed with all means. (statement)  
• If ownship can reduce speed to green vessel position all crossing vessels will clear without further shiphandling.  (sensed)

 Let's look at the second part: safe position.

Ownship is not in a safe position.  Ownship just sailed into trouble waters without altering course to safe ground. Safe speed is only option ownship have now. There is no room for any mistake or neglect in any way. 

End of Ex 01-04