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Two systems of map references predominate in navigation, those being the Geographic Coordinates and the Universal Transverse Mercator (UTM) Grid of which the Australian Map Grid (AMG) is a part.

On all standard maps produced in accordance with the AMG there is a grid composed of two sets of equally spaced parallel lines which intersect at right angles. The distance represented between the grid lines is dependent on the map scale with all maps from 1:25,000 to and including 1:100,000 having intervals of 1,000m and 1:250,000 having intervals of 10,000m.

Eastings
The vertical grid lines (those running North/South) are called Eastings. The lines of easting are numbered from left to right (west to east).

Northings
The horizontal grid lines (those running East/West) are called Northngs. The lines of northing are numbered from bottom to top (south to north).

Grid references
Grid references are a combination of an easting and a northing, always in that order and concatenated to create one number like 935655, or more correctly GR935655. Such a grid reference denotes the bottom left hand corner of a square, the length of the side being dependent on the size of the grid reference. Any easting and northing grid reference is a reference to an area, not a point.

Size of reference Length of side
Four figure reference 1000m
Six figure reference 100m
Eight figure reference 10m
Ten figure reference 1m

Grid References Diagram

If an easting and northing coordinate is given then be aware that the true location intended by the event director could be anywhere within the area defined in the above table.

In contrast, a Geographic Coordinate refers to a point and no ambiguity is acceptable.

Other maps, often older and frequently with obscure or out dated scales, are sometimes supplied by the event director. These may show road alignments that no longer exist or have changed beyond recognition or bear markings indicating physical features like buildings that are nothing more than a memory, any of which may have been used by the director in the clues or instructions.

Road Junctions
This clue type is usually easy to identify and solve as it simply comprises a list of junctions and the direction to take at that junction.

XRSO SRSO SRSO SRSO SRSO TJTR SRSO XRTR TJTR

SRSO SRSO SRSO SRSO SRSO SRSO XRTR SRSO SRTL

Tulips
If the junction on the map is shaped as below, going straight on from A to B you would leave a road on the right. However also turning from C to A or from B to C you would leave a road on the right.

Road Junction Tulip

For each of these three cases the junction in the roadbook will look the same in it's simplest form.

Road Junction Tulip Right

Similarly, to leave a road on the left you could be going straight on from B to A, taking a right from A to C, or turning right at the T-junction from C to B.

These three cases will all be a mirror image of the above illustration.

Road Junction Tulip Left

The event director might be nice to competitors and draw the tulips to a reasonably accurate depiction of the road as shown on the map with entry and exit roads at close to the correct angles but many don't do so.

Strip charts, herringbones,'chicken scratchings' or 'straight lines'
A strip chart, herringbone or chicken scratching is created by following the route itself and pulling it out straight, all the other roads being snipped off leaving short tails, as below, where the start is indicated by the ball.

Strip Chart

Note:

  • The fourth intersection which is presumably but not necessarily a crossroads, it simply indicates that you will pass through a junction at which you will leave a road to both your left and your right.
  • The seventh intersection which again is presumably but not necessarily a crossroads, it simply indicates that you will pass through a junction at which you will leave two roads to your left.

Be aware that the:

  • Strip chart may or may not include all junctions between the start and end points
  • Start ball may be missing
  • Strip chart may read from finish to start if the start ball is missing
  • Director might even make it a circular strip chart with no defined start or end points.

Pass throughs
These will be a series of 4 digit 'eastings & northings' denoting a sequence of grid squares through which the road will pass in the shortest distance. The grid squares may or may not be adjoing.

Avoids
The opposite of pass throughs.

Grid lines
A series of two digit numbers indicating which easting or northing grid line to pass through in sequence. Usually easy to detect by comparing the first two with your current known plotted position.

Grid squares
The same basic clue as the grid line in a different format. A series of four digit numbers indicating which grid squares to pass through in sequence. Like grid lines, usually easy to detect.

Postage stamps
Each 'stamp' represents a grid square and the markings on the edges represent where the road traverses the grid line. Time controls may be indicated by dots within the 'stamp'.

Road tracings
Each piece is a tracing of a road portion and should be to the correct scale. Tracing onto acetate will assist but getting the pieces in order and on the right road can be challenging.

Line Drawing

Compass directions
These give the direction to leave the junction.
ENE SSE NE E WNW NE

Clock times
You enter the junction along the direction of the hour hand and leave in the direction pointed to by the minute hand.
8:05 7:55 6:15 8:25 6:20 9.05

Others
There may be reference to buildings either real or demolished or anything else for the director to dream up.