Thought it was time that I add a bit on here about "navigation basics". As Dave has mentioned before a navigator has a very important role within a rally car that can easily overlooked. So here are a few of the basics....
You will need;
A good pencil (2b's are perfect for plotting)
OS Landranger Map (1:50 000)
And a roamer (see below)
How to plot a map reference
Ok what is a map reference? Well at its basics it's a series of numbers which defines a place on the map. Most road rallies and classic rallies use 6 or 8 digit references but to begin with we will concentrate on 6 digit ones for now
Lets have a look at a map
You will notice all around the map a series of numbers, some going vertically and some horizontally
The horizontal numbers are known as "eastings" (going up in numbers to the east)
The verticall ones are known as "northings" ( going up in numbers to the north)
Each individual square on the map is called a "grid square"
Each blue line between the squares is called a "grid line"
First rule of plotting is you plot the eastings first then the northing or how I was taught was "you crawl before you can stand up"
Ok let's plot a grid square. No tools needed!
Ok the reference we will use is 58,01
If you have plotted it correctly the square should have the number 126 in the centre of the square!
For the next step we need the " roamer" I use. Have a look at it, there's a lot of information on it but I will keep to the basics for now
To plot 6 figure references we need to use the top right hand corner
You can see it breaks the square into 10ths. These are the next number in a 6 digit reference
For example; using the previous square for the next reference
The map reference we are going to plot is 584,015(1/2)
(I know it doesn't look like a 6 digit one but they do include halves and sometimes quarters)
So we know the grid square is the first 2 digits in the reference. Using the roamer on the 58 grid line measure in 4 to the east, then 5 1/2 to the north ( as below)
And that is a basic map reference. On a modern road rally you will have pages of map references like these to plot to make sure your on the right route( see below for an example)
Hope this hasn't been too confusing, Si
Edited by minisi35, 15 April 2013 - 09:42 PM.
