1.14.1. Types of bearings

Bearings are measured in two ways:

1. Whole circle bearing (WCB)
2. Reduced bearing (RB) or Quadrantal bearing (QB)

Bearings are measurements used in surveying to indicate the direction of a survey line relative to a reference point. There are two primary methods of measuring bearings: Whole Circle Bearing (WCB) and Reduced Bearing (RB).

• Whole Circle Bearing (WCB): This is the angle made by a survey line with the magnetic north direction, measured in a clockwise direction ranging from 0° to 360°.
• Reduced Bearing (RB): Also known as Quadrantal Bearing (QB), this measures the angle made by the line with respect to the north or south direction, focusing on the smaller angle created. It divides the horizontal plane into four quadrants: NE, SE, SW, and NW.

Imagine standing at a central location with four walkways leading out. If we refer to the walkway heading directly north, and measure the angles in relation to it for the other pathways, we'd essentially be describing the bearings. WCB gives us a complete 360° view, while RB simplifies directions into a more intuitive form using four quadrants.

The whole circle bearing (WCB) of a survey line is the angle made by a survey line with the magnetic north direction, always measured in clockwise direction. It can have a value between 00 and 3600.

The Whole Circle Bearing (WCB) is a universal way to define a direction by measuring the angle formed with the magnetic north. For example, if a survey line is oriented directly east, it would have a WCB of 90°. If it's oriented west, the WCB would be 270°. This method helps in making calculations straightforward, particularly in triangulation or calculations involving multiple survey lines.

Consider a clock. The WCB is like telling the time—12 o'clock straight up (0°), 3 o'clock pointing to the right (90°), 6 o'clock downward (180°), and 9 o'clock to the left (270°). Just as you can tell time by where the hands are pointing, you can define direction using WCB.

The reduced bearing (RB) or quadrantal bearing (QB) of a line is the angle made by the line with the either magnetic north or south direction, whichever is a smaller angle.

Reduced Bearings provide a more concise way to understand directions by focusing on the smallest angle to the north or south. The horizontal plane is divided into four quadrants; in the first and fourth quadrants (NE and NW), angles are measured towards the east or west from the north, whereas in the second and third quadrants (SE and SW), they are measured from the south. For example, an angle of 30° east from north would be written as N 30° E.

Think of a compass needle, which tells you where north is. The RB is like giving someone simple directions: instead of saying 'head northeast' (WCB), you just say 'turn 30° right from north' (RB). It's about making it easier to communicate directions.

The north-south direction and the east-west direction divide the horizontal plane into four quadrants. Thus, in quadrants I and IV, the reference direction is north and the angle is measured either to the east or west. In quadrants II and III, the angle is measured from the south, either to the west or east.

The concept of quadrants is crucial when using Reduced Bearings. The four quadrants are formed by the north-south and east-west lines intersecting:

1. Quadrant I: North and East (0° to 90°)
2. Quadrant II: South and East (90° to 180°)
3. Quadrant III: South and West (180° to 270°)
4. Quadrant IV: North and West (270° to 360°) This division helps in clearly establishing a reference for bearings, facilitating easier navigation and surveying.

Think of a map: if you draw an X from the north to south and east to west, you create a grid. Each section (or quadrant) of this grid helps you identify where to go based on simpler north/south and east/west directions. It’s like giving someone very easy directions based on where they stand.

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