2. Objectives: 1. Describe shiphandling characteristics. 2. Demonstrate how to calculate advance, transfer, and turn bearings. 3. Determine position in relation to track 4. Demonstrate how to calculate danger bearings.
3. Handling Characteristics Turning Circle - The path followed by the pivot point of a ship during a 360 degree (or more) turn using a constant rudder and speed. - The pivot point for most warships is about 1/3 the way aft from the bow when the ship is going ahead. It is important to note that the bow turns inside the path of the turning circle, and the stern swings outside the turning circle.
4. 60 C D E U F G A T H B P Typical Ship’s Turning Circle
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6. Handling Characteristics Advance - The distance gained in the original direction the ship was traveling from the point that the rudder was put over to the point where the ship is steady on the new course. - The maximum advance will be for a 90 degree turn.
7. End of Turn Start of Turn Original Course Advance Measured from the point the rudder was put over to the point where the ship is steady on its course Final Course
8. Handling Characteristics Transfer - The distance gained, perpendicular to the original course from the point where the rudder was thrown over, to the point where the ship is steady on the new course.
9. End of Turn Start of Turn Original Course Distance measured perpendicular to the original course Final Course Transfer
10. Handling Characteristics Tactical Diameter - The transfer of a vessel during a 180 degree turn. Final Diameter - The diameter of the approximate circular path that a ship describes if the rudder is kept over indefinitely.
11. E B A F D Tactical Diameter C Tactical Diameter Final Diameter Original Course 000 Wheel Over
12. Handling Characteristics Standard Tactical Diameter - A specified tactical diameter is laid down in tactical publications for naval ship types (i.e., frigates, destroyers, cruisers, and aircraft carriers). - This data is used when ships are maneuvering in company to ensure all ships turn at the same rate, and the correct spacing between ships is maintained.
13. Handling Characteristics Standard Rudder - The amount of rudder required to ensure a warship achieves the ordered standard tactical diameter. - This rudder amount will vary between warship classes.
14. E B A F D Tactical Diameter C Tactical Diameter Final Diameter Original Course 000 Wheel Over
15. Handling Characteristics Turn Bearings - In order to plot the position at which the ship must put the rudder over (to turn onto a planned track), the figures for advance and transfer must be calculated using interpolation , unless the specific speed and rudder combination is defined in the tables.
17. ADVANCE AND TRANSFER TABLE SPEED RUDDER ADVANCE/TRANSFER ANGLE 45deg turn 90deg turn YDS YDS 6KTS STD. 117/55 135/85 FULL 67/40 55/55 10KTS STD. 80/45 125/80 FULL 45/30 75/50 13KTS STD. 125/85 150/100 FULL 100/75 80/55
18. Handling Characteristics Turn Bearings - Should interpolation be necessary, the figure for transfer is used first to find the point where the ship will be steady on the new track. - The figure for advance is then used to determine where the rudder must be put over in order to intercept the new track.
19. 100 0 100 200 300 TR Scale in Yards TR - 000 T TR - 050 T N
20. Advance and Transfer Table Angle of Turn Advance Transfer 15 180 18 30 230 30 45 270 60 60 310 110 75 330 170 For a 50 degree turn: Advance = 283 yds Transfer = 77 yds
21. A 100 0 100 200 300 B TR Scale in Yards 77yds 90 º TR - 000 T TR - 050 T N
22. A 100 0 100 200 300 B TR TB 270 Scale in Yards Turn Point Steadying Point TR - 000 T TR - 050 T 281 Yds N
23. A 100 0 100 200 300 B TR TB 270 90 C D Scale in Yards TR - 000 T TR - 050 T N
24. Lt Ho WO A 070 005 Actual Track - 1 Actual Track - 2 Pick a turn bearing navaid close to the beam.
25. WO A 070 005 Actual Track - 1 Actual Track - 2 Pick a turn bearing navaid parallel to new course – automatic adjustment to back on track Lt Ho
26. - Many means are provided to help keep a ship on track (i.e., specially constructed ranges, direction lights,etc.). - However, should nothing be provided specifically designed for the purpose, it is often possible to select an object that the ship runs towards and use as a head bearing. By knowing what the object should bear, the determine which side of track the ship lies. Establishing Position
