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Lesson 7: Dead Reckoning: 

11/7/2007 Lesson 7: Dead Reckoning

Slide2: 

AGENDA: Six Rules of Dead Reckoning Define/Apply the 3 min & 6 min Rules Plot/Label a Running Fix Applicable reading: Hobbs pg. 134-138. Lesson 7: Dead Reckoning

Dead Reckoning: 

Dead Reckoning - DR is the process of determining a ship’s approximate position by applying, from its last known position, a vector or a series of consecutive vectors representing the true courses steered and the distance run as determined by the ship’s speed and time, without considering the effects of wind and current.

Dead Reckoning : 

Dead Reckoning - DR is derived from DEDUCED, or DED, reckoning which was the process by which a vessel’s position was computed trigonometrically in relation to a known point of departure.

Six Rules of DR : 

Six Rules of DR

Slide7: 

Plot a DR Position Every Hour on the Hour 0900 1000 1100

Plot a DR Position at Every Course Change: 

Plot a DR Position at Every Course Change 20 24 29 C-125 c-090 C-080

Plot a DR Position at Every Speed Change: 

Plot a DR Position at Every Speed Change 15 21 27 S-10 S-15 S-5

Plot a DR Position for Every Line of Position (LOP): 

Plot a DR Position for Every Line of Position (LOP) Tank 0826 0826

Plot a DR Position for Every Fix or Running Fix: 

Plot a DR Position for Every Fix or Running Fix 46 37 0937 R-Fix

Plot a new Course Line with  Every Fix or Running Fix: 

Plot a new Course Line with Every Fix or Running Fix 0937 R-Fix C-075 S-15

Time-Speed-Distance Calculations : 

Time-Speed-Distance Calculations - These calculations can be made using a nautical slide rule, electronic calculator, set of precomputed tables, or speed nomogram. D = S x T where: D = distance traveled note: ( 1 nm = 2000 yds) S = speed in knots T = time in hours

Three Minute Rule : 

Three Minute Rule - The distance of travel of a ship in yards in three minutes is equal to its speed in knots multiplied by 100. D = S x 100 where: D = distance traveled S = speed in knots

Six Minute Rule : 

Six Minute Rule - The distance of travel of a ship in nautical miles in six minutes is equal to its speed in knots divided by 10. D = S / 10 where: D = distance traveled S = speed in knots

Lesson 8: Running Fixes: 

11/7/2007 Lesson 8: Running Fixes

Slide20: 

AGENDA: Procedures for advancing two or more non-simultaneous LOP’s. Procedures for plotting/labeling running fixes. Applicable reading: Hobbs pg. 138-144. Lesson 8: Running Fixes

Slide21: 

STEP #1: Take a bearing to the Nav Aid and draw on the chart. Mark your DR position from the last fix using ordered course and speed. Procedures for Advancing an LOP

Slide22: 

Light Running FIX 9 9 9 9 9 9 9 9 9 9 9 5 5 5 5 11 11 11 11 11 11 11 11 6 pa FL 6s 58ft 9M Tank Long Point 20 20 20 20 20 20 21 20 20 20 21 21 21 21 21 21 23 23 23 23 23 23 15 15 15 15 17 17 17 17 19 19 19 19 C- 085 T S - 12 0800 0810 0810

Slide23: 

STEP #2: Take a second bearing and record it, usually waiting at least 20 minutes to allow for bearing separation between LOP’s. Procedures for Advancing an LOP

Slide24: 

Light Running FIX 9 9 9 9 9 9 9 9 9 9 9 5 5 5 5 11 11 11 11 11 11 11 11 6 pa FL 6s 58ft 9M Tank Long Point 20 20 20 20 20 20 21 20 20 20 21 21 21 21 21 21 23 23 23 23 23 23 15 15 15 15 17 17 17 17 19 19 19 19 C- 085 T S - 12 0800 0810 0810 0830 0830

Slide25: 

Procedures for Advancing an LOP STEP #3 Determine distance traveled in time between LOP’s (at ordered course and speed). Measure this distance from the point where the first LOP intersects your track. Mark this point on the DR track.

Slide26: 

Light Running FIX 9 9 9 9 9 9 9 9 9 9 9 5 5 5 5 11 11 11 11 11 11 11 11 6 pa FL 6s 58ft 9M Tank Long Point 20 20 20 20 21 20 20 20 21 21 21 21 21 21 23 23 23 23 23 23 15 15 15 15 17 17 17 17 19 19 19 19 C- 085 T S - 12 0800 0810 0810 0830 20 min @ 12 kts = 4 nm 4 nm 0830

Slide27: 

STEP #4: Parallel the first LOP through this point on the DR. Label this advanced LOP with both the original time and the time it was advanced to. Procedures for Advancing an LOP

Slide28: 

Light Running FIX 9 9 9 9 9 9 9 9 9 9 9 5 5 5 5 11 11 11 11 11 11 11 11 6 pa FL 6s 58ft 9M Tank Long Point 20 20 20 20 21 20 20 20 21 21 21 21 21 21 23 23 23 23 23 23 15 15 15 17 17 17 17 19 19 19 19 C- 085 T S - 12 0800 0810 0810 0830 20 min @ 12 kts = 4 nm 4 nm 0810-0830 0830

Slide29: 

Procedures for Advancing an LOP STEP #5: The point where this advanced LOP and the second LOP cross is the running fix position. Mark a circle and properly plot and label the “R-FIX” with the time. Plot a new course and speed line IAW the six rules of DR.

Slide30: 

Light Running FIX 9 9 9 9 9 9 9 9 9 9 9 5 5 5 5 11 11 11 11 11 11 11 11 6 pa FL 6s 58ft 9M Tank Long Point 20 20 20 20 21 20 20 21 21 21 21 23 23 23 23 23 23 15 15 15 17 17 17 17 19 19 19 19 20 21 C- 085 T S - 12 0800 0810 0810 0830 0830 0810-0830 20 C- 085 T S - 12 R-FIX 0830

Slide32: 

China: Houjian Class Iran: Hudong Class Speed: 34 kts Armament: -6 C801/801 SSM -1 dual 37mm cannon -2 dual 30mm cannon C801 Range: 20nm C802 Range: 60nm

Slide33: 

PLATFORM OF THE DAY: FFG-7 OLIVER HAZARD PERRY CLASS FRIGATE Sensors: AN/SPS 49 Radar AN/SPS 55 Radar Mk 92 FCS AN/SQS 56 Sonar AN/SQR 19 TACTAS Missions: ASW, ASuW, AAW WEAPONS: Mk 13 GMLS -SM-1 MR SAM -RGM-84 Harpoon Mk75 76mm Oto Melara 20mm Phalanx CIWS Mk 32 SVTT (6 tubes) SH-60B (2)