Actual MovementSpeed Triangle

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Actual Movement
Speed Triangle
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Actual Movement/ Speed Triangle

• AGENDA
• Speed triangle terminology
• Application Vector Diagram
• Applicable reading MBW Ch 4.

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The Speed Triangle
Terms

• Vector - Graphic representation of an object
  moving in a given direction at a given speed.
• e - The center of the maneuvering board.
• er - Vector representing the reference ships
  course and speed.
• em - Vector representing the maneuvering
  ships course and speed.
• rm - Vector representing the direction and
  speed of relative motion (DRM SRM).

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The Speed Triangle

• Three Sides of the Speed Triangle
• 1. er vector
• 2. em vector
• 3. rm vector

r
er
rm
e
m
em
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The Maneuvering BoardSpeed Triangle
Essential Skills 1. Reading the problem 2.
Selecting the reference ship and speed scale (It
is recommended to always use 51 scale
for speed). 3. Drawing the er vector 4.
Constructing the relative plot 5. Drawing the
rm vector 6. Finding the em vector
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The Maneuvering BoardSpeed Triangle

• If you are on course 090ºT, speed 10 knots, and
  sight a ship on course 270ºT, speed 15 knots,
  what are the er, em rm vectors?
• 1. Plot both courses and speeds from the center.
• er vector - 090 T, 10 knots
• em vector - 270 T, 15 knots

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em vector
er vector
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The Maneuvering BoardSpeed Triangle

• If you are on course 090ºT, speed 10 knots, and
  sight a ship on course 270ºT, speed 15 knots,
  what are the er, em rm vectors?
• 1. Plot both courses and speeds from the center.
• 2. Connect the ends of the er em vectors
  (from the er to the em) to form the rm vector
• rm vector - 270ºT, 25 knots

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S
rm vector