Saturday 3 March 2012

Maps and Compasses - The Basics

So this is going to be a very basic introduction to maps and compasses and how to use them. These two tools are essential to make mountaineering enjoyable and to avoid getting lost! Its like riding a bike really, once youve learnt how to use them efficiently and correctly - you'll never forget!

Maps

Right. In the UK we have a very efficient mapping system called Ordnance Survey. The people at Ordnance Survey have being creating maps for more than 200 years. These days they have covered the whole of the United Kingdom (England, Scotland, Wales and Northern Island) in both scales of 1:25000 and 1:50000. That's a total of 607 sheets - only for leisure! They also do many road maps and mapping for business etc - but we're not interested in those. The 1:25k and 1:50k maps are the ones used for our scale of hiking.
1:25000 map exctact of Moel Siabod - (See Route)
Image produced from Ordnance Survey Get-a-Map service.
Image reproduced with kind permission from Ordnance Survey

1:25000 - Basics
  • 4cm on the map is 1km in real life
  • Contours are 10m apart
  • Individual buildings tend to be marked
  • Large majority of fence-lines and paths marked
  • Mainly used for micro navigation
1:50000 - Basics
  • 2cm on the map is 1km in real life
  • Contours  are 10m apart, but much less detailed
  • Towns are much less detailed
  • Only major paths and boundaries shown
  • 1:50000 map exctact of Moel Siabod - (See Route)
    Image produced from Ordnance Survey Get-a-Map service.
    Image reproduced with kind permission from Ordnance Survey
  • Much better for large-scale navigation - from peak to peak for instance.
So now you should know your basic way around a map, more on actually using them, different symbols etc, in a later post ;)







Compasses
So compasses, despite their simplicity - can be quite difficult to use - especially in their most efficient way.

A basic mountaineering compass

Right so, to the left. That's a compass. One you can actually use for navigation. Not the dodgy one you get on your iPhone!

The main way of using one is obviously to find north. Now the red needle always points to magnetic north.

Now that is slightly different to grid north on the map - but only by a few degrees so for our purposes its negligible.

Again, in my next post about this sort of stuff Ill say some more on the lines around the main part but for now, if you turn the map so its top faces the same way of the needle - you will have set your map!

This means that if you follow a path along on the map - it will be going in the same relative direction on the ground - this makes navigation much much easier for beginners.

So there's the basics. I hope to develop on this into much deeper detail in the next couple of weeks so watch this space!

Please leave any feedback in the comments section below :D Thank-you!



1 comment:

  1. That would be great to hike mountains, but I think I'm moderate when it comes to my skill level.

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