Chapter 5- Situational Awareness for Chief Officer

Part one: Dover Strait traditional maritime power conflict zone

Aftermyth of Container ship collided with cruiser 1999

The Dover Coastguard recording of VHF Channel 16 timed an unidentified call: ‘Starboard, starboard, starboard’ at 00 hours 54 minutes 37 seconds. It is likely that this was made by one of the two vessels immediately before the collision.

The collision happened in Dover Strait at 0055 on 24 August, 1999. 20 years ago, a time of new DGPS positioning is not universal and Voyage data recorder VDR are not available. ARPA just merged around the corner at 1997. It is the darkest time in the industrial by visual lookout transit to ARPA lookout. However, the ARPA performance standard are more or less the same copied from visual lookout. For example, IMO Resolution A.823(19) adopted on 23 November 1995 PERFORMANCE STANDARDS FOR ARPA.

3.8.3 An ARPA should present within three minutes of steady state tracking the motion of a target with the following accuracy values (95% probability values). 

The acceptable CPA accuracy values (95% probability values) are 0.7 NM. This is plotted with 3 minutes of steady state target. In another words, if a target’s tracking is less than 3 minutes it ARPA data is quite questionable and should be used at OOW’s own risk by this standard. In real sea scenarios OOW just ignore the ARPA performance. No complaint why ARPA target present in this way as they don’t complain why radar echo are missing in close range. 

The collision investigation report made 20 years ago is outdated. The conclusions it recommended also need to be reviewed again. The lookout is progress from ARPA lookout to AIS lookout. The parameters input to ARPA and AIS are more accurate than 20 years before. The most significant one is the speed over ground SOG which is subjected to current and wind force influences. SOG is not recommended to be input into ARPA 20 years ago as they are part of estimation for the future speed over ground by past ship’s fix measurement. Now SOG can be obtained from DGPS with very high accuracy of 5 or10 meters allowance which are even good for berthing operation. Nobody talks about when we use Personal Piloting Unit PPU to docking we should use speed over water SOW today.     

We will take a quick review of the recommendations made in this report: To All Shipowners

1. When using more than one radar/ARPA, an anti-collision plot should be kept on only one. Our recommendation is to use 3 cm radar for small target in relative motion trail and 10 cm radar only for large vessel in APRA auto requisition mode for quick reference.  Only one mean of lookout is not healthy OOW should use visual lookout for small target and third radar for big vessel if available.  

2. To determine risk of collision using ARPA vectors, only the relative vectors should be used. True vectors should be used to determine aspect. Our recommendation is relative vector for 3 cm relative motion radar for small target and true vector true motion for 10 cm big target.

3. All bridge watchkeepers should be reminded that the speed input for an anti- collision plot on radar/ARPA should always be speed through the water not speed over the ground. Our recommendation is to use DGPS speed input for ARPA.

To Cruise Lines

4. The OOW of the Cruiser at the time of the collision should undertake further training in radar usage. Cruise Lines should ensure that this is carried out as soon as possible, they should also ensure that other bridge watchkeepers within their fleet are fully familiar with the bridge equipment with which they will have to deal. Our recommendation is to read and train as this book.

5. The Master of the Cruiser should draw up more explicit Standing Orders in accordance with the Company Procedure Manual to clarify when the OOW should call for assistance on the bridge. Cruise Lines should ensure that satisfactory masters orders are drawn up for all of their ships.

6. Cruise Lines should take steps to enforce and monitor the guidelines contained in their Procedures Manual about when watches should be doubled. The recommendation is to double the watch as much as possible.

Figure 5-1: Situational Awareness 6 minutes before collision in multiple targets

What situational awareness chief should have when tow collision sticks crossed one and other?

• §  We saw a collision point of these two vessels. Time to collision TTC for No.7 target is about 6 minutes and for No.5 target (red speed vector) is about 5 minutes. 
• §  NO. 5 target pass collision position one minutes earlier. 

At this moment 0049 hours, a message was heard on VHF, Channel 16, saying “Passenger ship approaching Foxtrot Freeboy [i.e. F3 Buoy] course 215, please”. This was about 4 - 5 minutes before the collision. The ships identified themselves and, while replying, the OOW looked to starboard and saw No.7 ship flashing a light forward of his starboard beam. This is positive identification of target which is a must-be and hardest part in an multi target situation. 

The No.7 ship asked the cruiser to come to starboard to pass around her stern. The OOW seems at this point to have become confused with the ARPA plot. He stated that he thought the No.7 ship would pass about 0.6 miles ahead of him. 

- OOW is not familiar with True vectors presentation in radar. OOW did not take ownship’s movement into true motion speed vector consideration. This is quite unbelievable as he has two years OOW sea experience already.  

- If OOW had used 10 cm radar for large vessel auto acquisition, ARPA data may help to clarify the CPA value without guessing

He therefore agreed to No.7 ship’s request. Accordingly, at about 0051 he altered course about 7 degrees to starboard to 220^o (T) and (G) to increase the apparent passing distance. 

–      OOW has no idea of how many degrees course change for an one nautical mile distance target? Have you? At least 20 degrees course should change for blossom effect of a 300 meters vessel. 

–      altered course about 7 degrees to starboard: is for head-on situation or small fishing boat, not crossing or big vessel which is not enough to go around No.7 vessel’s stern.

–      No.7 vessel’s stern: located 90 degrees starboard side. It is almost impossible to alter 90 degrees without hard over rudder to accomplish. 90 degrees turn is a dangerous move to passengers on board. 

Figure 5-2: Situational Awareness 3 minutes before collision in multiple targets

At this moment 0051 hours, The OOW realised that the two ships were very close and that rapid action was needed. The OOW put the engine combinators (i.e. bridge controls of main propellers) to full astern and the helm hard to starboard.

–      No matter how emergency, the TTC should be verified at RADAR. Time to collision TTC for No.7 target is about 3 1/2 minutes and for No.5 target (red speed vector) is about 3 minutes.

–      The OOW put the helm hard to starboard: 3 minutes before collision should be enough. In this case, rudder effect is reduced by put the engine combinators (i.e. bridge controls of main propellers) to full astern. This is what they called Titanic Effect when OOW saw iceberg he pulled full astern engine. In 1^st stage of turn the rudder plate need propeller expel current to push sideward to increase ship’s body’s resistance to assist the turning.  Too complicated. Please refer to figure 4-6 different size container vessel turning with hard over rudder. Every ship has different characteristics in his turning and stopping. Actual reaction of ship’s movement only knew by his OOW and Master.

At this moment 0052-0053 hours, The cruiser was swinging to starboard, but the engine movement was ineffective in reducing the vessel’s speed.

At this moment 0054 hours, The cruiser hit the port side of the No.7 target approximately at right angles. 

– This means cruiser arrived later than No.7 target and course 220 degrees(T) almost unchanged.  

- This is a good luck for thousands lives on board and passenger’s cabins all over ship side.

- Originally, Cruiser will pass collision point earlier as figure 5-1.

- Full astern the engine had saved passenger’s life and avoid ownship been capsized.

Figure 5-3: Situational Awareness of angle of blow

Angle of blow

In figure 5-3 ownship is north bound, the relative bearing of target vessel’s stern is those blue line. In the upper part there are three situations with visual. Lower part are three situations with ARPA.

–      No. 1 is two vessels arrive almost collision point at same time. Target vessel’s stern relative bearing line almost unchanged (42.5 degrees to port side). The ARPA plot are as the lower situation one.

–      No. 2 is ownship arrive earlier, collision point is at ownship’s port side which is the case of No.7 target at 24 00 51 hours last example. Target vessel’s stern relative bearing line is increasing (from 42.5 degrees to 156 degrees port side). However, it is not enough to clear. The ARPA plot are as the lower situation two.

–      No. 3 is target arrive earlier, collision point is at target’s starboard side. Target vessel’s stern relative bearing line is decreasing (from 42.5 degrees to 5 degrees port side). However, it is not enough to clear. The ARPA plot are as the lower situation three.

–      First question is why bearing change is obvious the collision still happened? The reason is blossom effect as figure 2-8 horizontal angle augment of approaching vessel and her bearing change.

–      If we can read angle of blow from true motion speed vector in ARPA lookout we can know how to react to best aid collision in advance. 

–      In situation one two vessels arrive in same time, A/C to starboard side to increase her relative bearing or stop engine to decrease her relative bearing.

–      In situation two ownship arrive earlier, A/C to starboard side to increase relative bearing.

–      In situation three target vessel arrive earlier, stop engine to decrease relative bearing. 

–      In summary, judging from relative bearing change to decide what to do for best aid to collision.

• o   If target relative bearing decreased, stop engine to quicken the bearing decrease.
• o   If target relative bearing increased, alter course to other side of the target to quicken the bearing increase.

Part two: Singapore Strait maritime bunker power conflict zone

Aftermyth of VLCC collided with VLCS 2016

A 14000 TEU Very Large Container Ship (VLCS), was in collision with a Very Large Crude Carrier (VLCC) at approximately 23.55 LT (local time) on 3rd Aug 2016 in the Singapore Strait, about 3 km South-East of Sebarok Island. Both are Panama-flagged vessels. VLCC westbound sustained damage to her bow whilst VLCS sustained damages on her port quarter hull. 

The container ship VLCS just sailed from the Port of Singapore to join the eastbound lane of the TSS has overall length of 365.80 m, molded beam of 52.00 m and maximum draft of 12.00 m. The vessel has capacity to carry 14,000 TEU. 

The VLCC westbound sailed along SW traffic lane had deadweight of 319,999 DWT and gross tonnage of 164,241 GRT. The ship was en route from China to Iran under ballast.  Length Overall x Breadth Extreme:  333 m x 55 m.  Deep Draught 17.8 m / 21.1M.

Prior to the incident, VTIS provided traffic information to the two vessels and alerted VLCC that the vessel VLCS was crossing the traffic lane.VLCC sustained damage to her bow whilst VLCS sustained damages on her port quarter hull and 6 empty containers fell overboard.