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Radar Plotting – Head Reach. Farhan Saeed. Example 1. Own vessel steering 000°T, speed 15 kts. Target A = 1000hrs - 040°T x 12.0nm, 1006hrs – 040°T x 10.5nm, 1012 – 040°T x 9.0nm. Report on Target A for 1012hrs.
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Radar Plotting – Head Reach Farhan Saeed
Example 1 • Own vessel steering 000°T, speed 15 kts. • Target A = 1000hrs - 040°T x 12.0nm, 1006hrs – 040°T x 10.5nm, 1012 – 040°T x 9.0nm. • Report on Target A for 1012hrs. • At 1015 hrs engines are ordered Stop. At 1033hrs vessel is stopped in the water heading 350°T, Head Reach 1.8’. Find new CPA and cross ahead range of target A.
Example 5 • Own vessel steering 230°T, speed 12 kts. • Target A = 0500hrs - 180°T x 9.0nm, 0506hrs – 180°T x 7.5nm, 0512 – 180°T x 5.9nm. • At 0515 engines are ordered SLOW. At 0524 vessel is steady at new speed of 6 kts after advancing 1.2 miles. • State estimated new CPA for the target A.
Example 3 • Own vessel steering 050°T, speed 8 kts. • Target A = 1000hrs - 350°T x 12.0nm, 1006hrs – 351°T x 10.5nm, 1012 – 352°T x 9.0nm, 1018 – 354°T x 7.4nm • If from stopping engines, the head reach is 1.2’ after 18 mins, find the time at which to order stop so that the other vessel passes three miles ahead.