Lecture

1. Basic Navigation Leading Cadet Training Bearings and Distances Lecture 3

2. Revision B A We have examined setting the map, and working from Map to Ground. Remember Mag to Grid…..GET RID Grid to Mag…..ADD Now we will examine Ground to Map x

3. Compass Bearings Take a Bearing Ground to Map Select the feature on the ground to which you wish to take a bearing. Hold the Compass steady and level. Point the Direction of Travel Arrow at the feature, and rotate the Housing until the red end of the needle is in line with the ‘N’

4. Compass Bearings Take a Bearing Ground to Map Read the Compass Bearing shown on the housing from the Index Line This is your Mag Bearing which you can either travel along or convert to a grid bearing by subtracting the magnetic variation. (Remember Mag to Grid……Get Rid) x x

5. Compass Bearings A Take a Bearing Ground to Map Convert to a Grid Bearing. Place the Compass on the map and keeping the bearing set on the Housing, rotate the whole Compass until the Orienting Lines are parallel to the Eastings. The edge of the Compass should run through your position and show the bearing on the map. x

6. Compass Bearings Following a Bearing Hold your compass level and steady. Ensure the red end of the needle is in line with the ‘N’ on the Housing. Follow the direction of travel arrow. Line up the direction arrow with a physical feature (e.g. tree, pylon, tower). Use this as a reference point which is easier than following the compass every inch of the way.

7. Measuring Distance Measuring distances accurately is important because: it both keeps you on schedule and reduces the area of uncertainty in your position. There are two main ways of measuring and estimating distance: Timing Pacing

8. Distances Use the edge of the compass to measure the distance. or Use a strip of paper with 2 marks on it. Then measure the paper against the map scale:

9. Timing If you know how fast you can walk, you can work out how long it will take you to cover a known distance. For example: If the distance to your next objective is 2km, and you walk at 4kph – it should take you half an hour to reach it.

10. Timing By walking for half an hour or so, you should be close to your objective. This is not as easy as it sounds. Things to consider are: Going Uphill. Going Downhill. Fitness. Terrain. Load.

11. Timing Use your map and Naismith’srule to calculate the time it will take to get from one place to another. NAISMITH’S RULE Carrying little – 5kph + 1min for every contour climbed. with a load – 4kph + 1½min for every contour climbed. Plus ½ min for every contour down a STEEP slope

12. Timing Use your map and Naismith’srule to calculate the time it will take to get from one place to another. Therefore, with a load: 4kmper hour +30 mins for every200muphill and 10 minsfor every200m going downsteephills

13. Pacing Where very accurate distance measurement is required you could try counting the number of paces you take. This practice is used by orienteerers and with lots of practice can be very accurate indeed – But over short distances only.

14. Errors No matter which method of estimating distance you choose, there will be an error attached to it. This is particularly true when you are inexperienced. If you add to this the possible error in measuring direction, you will begin to see the difficulties that can lie ahead.

15. Errors Assuming a possible error of +/- 10% in measuring distance travelled and one of +/- 4° when measuring direction, you can see how quickly your area of uncertainty can grow as you walk along.

16. Errors 4 5 6 7 The lessons you must learn from this are: Keep the legs of your route as short as possible. Practice your compass work until you can take accurate bearings. Practice pacing and timing to reduce the error rate.

17. Check of Understanding Using a compass to take a bearing on a distant object what would you do first? Align the red compass needle with the object Turn the capsule housing to subtract the GMA Point the direction of travel arrow at the object Turn the capsule housing to align the orienting lines with the object

18. Check of Understanding What is the best way to measure distance on a map without a pair of dividers? Use the edge of a compass Draw a pencil line and measure it Make dividers with your fingers Fold the paper to use the map scale

19. Check of Understanding Measuring distances accurately whilst hillwalking is important because it: Calculates your speed of travel Keeps you on schedule Pinpoints your position accurately Chooses the shortest route

20. Check of Understanding How much time should be added for every 200 metres climbed with a pack, according to Naismith’s rule? 15 mins 20 mins 25 mins 30 mins

21. Check of Understanding Walking 1 km over reasonably flat ground in 20 mins. How long will it take to cover 4.5km? 40 mins 60 mins 90 mins 120 mins

22. Check of Understanding When walking on a bearing, in good visibility, the best technique is to . . . Follow your compass and ignore the countryside Select a feature along your intended route of travel Select an object 10 metres ahead and walk to it Send a team member 50 metres ahead and walk to them

23. Check of Understanding When navigating, in order to reduce errors to a minimum, you should . . . Always follow the established paths and tracks Walk as quickly as possible to your destination Measure distance and bearing as accurately as possible Never follow the established paths and tracks

24. Basic Navigation Leading Cadet Training End of Presentation