Pack 3 1

Navigation Pack 3

Pack 3 2

Lessons in Pack 3

• Contours

• Bearings

• Estimating Timings

• OS map symbols

Pack 3 3

Contour LinesContour lines indicate the height of the land above sea level.

They are useful to indicate hills and steep valleys.

Contour lines are at 10 metre height intervals

Contours close together indicate a steep slopeContours further apart

indicate a gentle slope

Pack 3 4

Contour Lines Activity

Match the hill profile (A-B) with the contour line (1-6)

Pack 3 5

Compass & Bearings

When using a compass, the big arrow in the middle of the plastic rectangle always points in the direction you want to go.

That’s true for finding a bearing on a map, and for walking on a bearing

The number where the big arrow crosses the dial is the compass bearing

The dial needs to be rotated to point North

This can be North on a map (the top of the map) when reading a bearing on a map

Or lined up with the red magnetic needle when walking on a bearing

The red end of the needle points North

(sometimes black)

Pack 3 6

Measuring a Bearing on a Map

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To find the bearing from Weston Church to Aston Church:

1. Point big arrow from Weston church to Aston church (or line up the edge of the compass)

2. Rotate the dial to point to North on the map (the top of the map) and align to the blue grid line

3. Read the number where the big arrow crosses the dial

From this example you can see that the bearing from Weston church to Aston church is 50o

Pack 3 7

Measure a Bearing

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What is the bearing from Aston church to the church in Chellaston?

Pack 3 8

Walking on a BearingTo walk on a bearing

1. Measure the bearing on which you want to walk from the map (e.g.145o)

2. Rotate the dial so that the big arrow crosses 145o

3. Move the whole compass so that the red magnetic needle lines up with the red arrow in the dial

4. Walk in the direction of the big black arrowThis is useful for navigating in

conditions of poor visibility (fog, snow, night)

Pack 3 9

Estimating Time for walks

Scouts walking pace

100m = 1min 30 second

Nasmith’s Rule (use when walking up hills)

For every 10 metre height gain add an extra minuteOrFor every brown contour line crossed add an extra minute

Estimate of time to walk from the sheep fold to Nether Moor:Horizontal distance: 800 metresHeight gained: 127 metres

800m x 1min 30sec = 12 minutes127m ÷ 10 = 12.7 minutesTotal time = 12 + 12.7 minutes = 24.7 minutes

Activity:

Estimate the time to walk from the top of Nether moor to Madwoman’s Stones

Pack 3 10

OS Map SymbolsHeights Rock Features

Water Features