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On 06th March 2008, AM at ship in DR 24˚ 12’ S 083˚ 46’ E, the azimuth of the star ALTAIR was 078˚(C) when chron showed 10h 38m 40s. If the chron error was 03m 24s FAST and variation was 3˚W, find the deviation for the ship’s head.
GMT 05 March 22h 35m 16s
GHA Ȣ(05d 22h) 134˚ 01.0’ Dec N 08˚ 53.2’
Incr. (35m 16s) 008˚ 50.4’
GHAȢ 142˚ 51.4’
SHA * (+)062˚ 12.4’
GHA * 205˚ 03.8’
Long (E) (+)083˚ 46.0’
LHA * 288˚ 49.8’
NOTE:
Working is very similar to that of azimuth- Sun, except that GHA Ȣ and SHA * have been used, which can be taken from the nautical almanac.
P = (360˚ – LHA)
= (360˚ – 288˚ 49.8’)
= 71˚ 10.2’
We know that :
Azimuth = N 73.8˚ E
T Az = 073.8˚ (T)
C Az = 078.0˚ (C)
Error = 4.2˚ W
Variation = 3.0˚ W
Deviation = 1.2˚ W
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On 30th Nov 2008, PM at ship in DR 48˚ 57’ N 173˚ 18’ W, the azimuth of the star VEGA was 296˚(C) when the GPS clock showed 07h 39m 22s. If variation was 1˚E, calculate the deviation of the compass.
d h m s
GMT 01 07 39 22
LIT (W) (-) 11 33 12
LMT 30 20 06 10
GMT 01 Dec 07h 39m 22s
GHA Ȣ(01d 07h) 175˚ 30.7’ Dec * N 38˚ 47.6’
Incr. (39m 22s) 009˚ 52.1’7 Lat 48˚ 57’ N
GHA Ȣ 185˚ 22.8’
Long (W) (-) 173˚ 18.0’
LHA Ȣ 012 04.8’
SHA * (+)080˚ 41.7’
LHA * 092˚ 46.5’
P = LHA
= 92˚ 46.5’
We know that :
Azimuth = N 60.53˚W
T Az = 299.47˚ (T)
C Az = 296.00˚ (C)
Error = 3.5˚ E
Variation = 1.0˚ E
Deviation = 2.5˚E
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On 01ST May 2008, AM at ship in DR 62˚ 11’S 179˚ 58’ E, the azimuth of the star SPICA was 312˚(C) when the GPS clock showed 13h 00m 08s. If variation was 10˚E, calculate the deviation of the ship’s head.
d h m s
GMT 30 13 00 08
LIT (E) 11 59 52
LMT 01 01 00 00
GMT 30d 13h 00m 08s
GHA Ȣ(30d 13h) 053˚ 50.6’ Dec * S 11˚ 12.5’
Incr. (00m 08s) 000˚ 02.0’
GHA Ȣ 053˚ 52.6’
SHA *(+) 158˚ 35.1’
GHA * 212˚ 27.7’
Long (E) (+) 179˚ 58.0’
LHA * 032˚ 25.7’
P = LHA
= 032˚ 25.7’
Azimuth =N 39.4˚W
T Az = 320.6˚ (T)
C Az = 312.0˚ (C)
Error = 8.6˚ E
Variation = 10.0˚ E
Deviation = 1.4˚ W
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On 13th Sept 2008 at ship in DR 30˚ 46’ N 090˚ 36’ W, the star RASALHAGUE bore 275˚(C) at 04h 36m GMT. If variation was 05˚W, calculate the deviation of the compass.
d h m s
GMT 14 04 36 00
LIT (W) (-) 06 02 24
LMT 13 22 33 36
GMT 14d 04h 36m 00s
GHA Ȣ(14d 04h) 053˚ 30.5’ Dec * N 12˚ 33.3’
Incr. (36m 00s) 009˚ 01.5’
GHA Ȣ 062˚ 32.0’
SHA * (+)096˚ 09.7’
GHA * 158˚ 41.7’
Long (W) (-) 090˚ 36.0’
LHA * 068˚ 05.7’
P = LHA
= 68˚ 05.7’
We know that :
Azimuth = N 89.9˚W
T Az = 270.1˚ (T)
C Az = 275.0˚ (C)
Error = 5.1˚ W
Variation = 5.0˚ W
Deviation = 0.1˚ W
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On 21st Jan 2008 at 0320 ship’s time, in DR 64˚ 12’ N 112˚ 18’ E, the azimuth of the star DENEB bore 034.5˚(C). If variation was 4˚E, and the ship’s time was 7h ahead of GMT, find the deviation.
d h m s
Ship’s time 21 03 20 00
Diff. (7 hr)(-) 07 00 00
GMT 20 20 20 00
GMT 20d 20h 20m 00s
GHA Ȣ(20d 20h) 059˚ 34.8’ Dec * N 45˚ 18.5’
Incr. (20m 00s) 005˚ 00.8’
GHA Ȣ 064˚ 35.6’
SHA * (+)049˚ 34.9’
GHA * 114˚ 10.5’
Long (E) (+)112˚ 18.0’
LHA * 226˚ 28.5’
P = (360 – LHA)
= 133˚ 31.5’
We know that :
Azimuth = N 34.4˚E
T Az = 034.4˚ (T)
C Az = 034.5˚ (C)
Error = 0.1˚ W
Variation = 4.0˚ E
Deviation = 4.1˚ W
The direction of azimuth .. don’t you think should be N34.4W. it’s written east..in question no. 5 of azimuth star. Please let me know if it’s correct.
Good day Sir,
Just a short question, how do we name every deviation obtained from Azimuth Sun sailing? How do we know its east or west? Thank you
I found a very usefull.
Keep it up
Sir!!