The basic requirements of participating in any event that can be classed as rallying are, naturally a roadworthy car, a competent driver and a navigator.
It is on the role and skills of the navigator that this series of articles will concentrate. Hopefully at some stage another club member will create a series "From the Right Hand Seat".
It is my intention to cover over a series of articles, sufficient detail of the art of navigation and map reading to enable the complete beginner to have enough confidence and enthusiasm to compete and catch the "rally bug".
Throughout the series I will use working examples of the techniques based on the map:
The Ordnance Survey Landranger 1:50,000 series, sheet 189, edition C, revised 1997.
This is the latest edition of the map that covers my home territory, and which is regularly used by the Blackpalfrey and other local motor clubs for rallies. This map sheet will cost you £4.95 at any good bookshop. I would recommend that you purchase one and you should then get the maximum benefit from this series of articles.
A word of caution – when purchasing this map sheet check that you are getting the correct edition as listed above. Some bookshops will still be holding old stock.
In describing the map I have used the term 1:50,000, what does this mean?
It is the scale of the map, the Representative Fraction (RF) which is the standard method of expressing a scale on all maps using the metric system. So a scale of 1:50,000 means that on this series of maps one centimetre on the map represents 50,000 centimetres on the ground. Translated into distances most can visualise, 1 centimetre on the map = 500 metres (546.8 yards)
A tip on how to estimate distance is to find an area on the map sheet you are familiar with. Drive to a known point on the sheet measure 500 metres on the map and locate that 500 metre point on the ground. Then compare your visual sight with the map distance. Using that known measuring point you should then (within reason) be able to work out distances quickly when reading a road off the map (e.g. from one junction to another etc).
Many experienced navigators have previously written articles about basic equipment, as you gain proficiency, see what others are using and develop your own preferences you will assemble your own personal kit. Here are some suggestions to get you started.
As I have previously said, this is not intended as a comprehensive list, but merely the basics to get you started. We all carry our own individual items that we think help us be better map readers and navigators.
As you gain experience I am sure you will develop your own ideas and kit. Please don’t forget to pass on your tips and ideas to others through the club magazine!
Open sheet 189, what do you see?
For your £4.95, you have purchased an extremely accurate, vertical representation of the area covered, 1600 square kilometres of SE Kent. At this stage I should comment that our 1:50,000 scale mapping is probably the most accurate in the world and the style of the Ordnance Survey mapping is copied world-wide.
This map sheet would have been updated using satellite imagery (photography) which depending on the satellite source can be accurate to less than 1 metre on the ground.
Now before we start studying the content of the map sheet, please look at the very important strip down the right hand side, known as the MARGINAL INFORMATION.
Everything you need to know about this map sheet and the others in the same series is contained here. It even shows you in detail how to read a map reference. More of this later.
Following the titles you have CUSTOMER INFORMATION – giving the edition and date of the map sheet. Yours should read:
© Crown Copyright 1998
If it doesn’t, you have purchased the wrong edition of the map sheet.
The next heading COMMUNICATIONS – covers roads & paths, rights of way, other public access and railways.
This is probably the most important part of the information section and I would recommend you study all these categories and learn to recognise them on the map itself. Pay particular attention to the colours used for the differing classes of roads and gradient signs, dual carriageways, fenced and unfenced roads etc. Also note the road categories from Motorways (Blue) down to other road, drive or track (White). The navigators’ habit is to refer to roads by their colours, so it is well worth the effort to remember them.
The GENERAL INFORMATION – section shows you all the symbols used to identify the location of a whole host of features, buildings and facilities. Again look and learn!
Tucked away at the bottom of this section is the sub-section Heights. Shown here are the contour lines and a commonly used feature – the SPOT HEIGHT. Have a look along a couple of the yellow roads on the sheet and see if you can see the spot height marks. You will now know why I said earlier an illuminated magnifier is an essential piece of equipment.
This strip is present on every map sheet in the 1:50,000 series. The strip is essentially standard on all sheets.
A Personal Tip – To help me I have removed a strip from a map sheet and stuck it onto the top surface of my map board. Now know where it is during the rally and don’t have to hunt around in the car during a rally trying to find it.
The general principles are: The map grid is a rectangular system of lines superimposed on the map. On this series they are 2cm squares shown with blue lines. Look at the bottom left of the sheet and you will see running along the bottom at the edge of the map detail, numbers starting at 85 and ascending EAST these are called EASTINGS.
At the same point you will also see the number 15, looking up the left hand edge of the sheet you will see these are increasing NORTH, these are NORTHINGS.
You will also see overprinted on the map detail the letters TQ. These letters identify the 100,000 metre square in which the grid reference (GR or MR) lies. The letters are a part of the Universal Transverse Mercator (UTM) Grid System. Don’t worry too much about these except you should be aware they exist as some rally organisers will occasionally include these UTM letters in grid references.
Now look at the bottom of the Marginal Information. You will see the heading about map references, this does explain in detail how a 6 figure reference is constructed. Now try to find the example reference of Boyington Court (TR 225 428) or (225428).
The 5 of the 225 indicates 5/10 – so it is half way between the 22 and 23 grid squares. The 428 is 8/10ths of the way up from the 42 grid line towards the 43 line. This gives a six-figure reference (accurate to 100 metres on the ground)
Normally, rally organisers will give you 8 figure references which can be shown as whole numbers and fractions (225¼428½) which has the effect of increasing the accuracy of the GR to 25 metres on the ground. You will also see these expressed as numbers from 1 to 9 (the 10ths) thus increasing the accuracy of grid reference to 10 metres on the ground.
These can be given as 7- or 8-figure references thus enabling a point to be plotted with accuracy. This is particularly important when there are two or more road junctions in the area. The accurate plotting of the GR and fraction will probably mean the difference between you taking the right or wrong route.
One little memory prompt used by the Armed Forces when teaching map reading in order to remember which way to read the map is "Along the corridor and up the stairs" translated this means read along the map left to right (West to East) and then up the map (South to North). You will probably want to devise your own memory prompt.
plotting the following GRs and working out the first stage of a rally
189 / 915457½ START Elvey Farm Hotel
912446½ SH 35
924445 (long way round triangle)
916438½ SH 33
906½434 SH 43
898429 SH 32
896½422 SH 24
NE 874412½ NW
864421½ SH 24
870429½ TC 1 End of First section
Route identifiers – plot the GR first, and work out your route using the shortest practical route using coloured roads only. Then use these identifiers to check you have used the correct GR’s. Next month I will include a trace overlay to show you the correct route.
I hope you will find this of some use to you, next month I will continue introducing a couple of other navigational techniques, and we will go a little further along our rally route.