March 2021 TCN

Q.1) Your vessel is South East of Merapas Island (00°55.7’ 104°55.7’E) and steering a course of 352°(G) when the following bearings were observed. Gyro error = 2°(H).
0930 hrs Merapas 1st South tip – 292°G
0950 hrs Merapas 1st South tip – 262°G
1010 hrs Merapas 1st South tip – 227°G
1010 hrs Merapas is (01° 02.8’N 104°50.0’E) – 284°G
Find i) Position at 1010hrs
ii) CMG
iii) Set and rate if current between 0930 hrs and 1010 hrs.

Answer:

a) 1010 Hrs Position: 01°00.6’N; 105°00.5’E
b) CMG – 341°T
c) Set & Rate: 258°T x 1.8 kts

Q.2) During the evening twilight in DR position of 01° 50’ N, 104° 30’ E, star ‘Rigel’ (azimuth 080° T) at 1800 hours, gave the ship’s longitude as 104° 23’E. Ship was steering 125°(T) at 10 knots. At 2100 hours ‘Horsburgh’ Lt. was observed to bear 260°(T). If the current is known to set 210°(T) at 2 knots, find the ship’s position at 1800 & 2100 hours. What is the course & speed made good?

Answer:

1800 Position: 01°45.6’N; 104°23.8’E
2100 Position: 01°23.6’N; 104°45.1’E
CMG – 136°T
SMG – 10.3 Kts

Q.3) A vessel completes loading in STS operations at 1830 hours to her summer draft of 19.5 meters
in 01O°0’N, 104° 12.0’E. She is to discharge this cargo at Chennai, India. Plan a safe passage for her
through the TSS on chart 5118 keeping in mind full safety standards / requirements / recommendations for a vessel of this type & size. Plot courses & alteration points on the chart and record details in the answer script.

Plan the Passage as per Question