Hi..I have been looking over my maps (M40) and reflecting on my races.  I felt at the time that I was overriding horizontally and missing turnoffs. One such error cost me about 6 places as I had just passed all those people.  When I look at some of the maps that are at 1:15000 or 1:10000 or 1:20000 they seem to have the same width of the blue 500m line..or some of them do...Is that supposed to be the case?.  I would have expected wider spacings on say 1:20000 than 1:15000?  Am I wrong?

Cheers

T.Rev

Map Standard 2007:

601 Magnetic north line
Magnetic north lines are lines placed on the map pointing to magnetic north. Their spacing on the map should be 20 mm which represents 300 m on the ground at the scale of 1:15 000. North lines may be broken where they obscure small features such as boulders, knolls, cliffs, stream junctions, path ends, etc.
Colour: blue.

Michi

Cheers Michi..so shouldnt the spacing (20mm) have changed when the map scale changed?..eg Parwolki and Idzbark were 1:20000 but the spacing was still 20mm.

By way of contrast the 2 Freisdadt maps we rode were 1:10000 and the spacing was 50mm.  Surely that isnt still 300m though?

Im still confused..like I was at control 12 on one of the Polish maps!

In NZ we have a ruler scale on the maps as well.

Cheers

T.Rev

I draw my maps with a spacing of 50 mm at 1:10000 or 1:15000.
So this means the same spacing becomes more meter in nature with increasing scale. Since you know the scale it is easy to figure out what is distance in between but you know it is allways the same spacing on the maps. I found that 20 mm interrupted the map with to many lines. What do you think about, is it to less?

This spacing would not fit the spec then would it?  which is 20mm at 1:15000 which equals 300m.  My point is if it is 50mm at 1:10000 then what does the 50mm then represent..or if it is 50mm at 1:20000 what does taht represent.

Apart from experience how can u actually tell when u look at a map from one country compared to another as to what distance the horizontal measure off north lines actually is so you can then apply that to a vertical or diagonal leg and get an idea of distance on the ground.  In NZ we get around those variations..which shouldnt exist by having a rulee scale as an aide.

If a visitor/novice comes to an international event and then goes to another they should be able to look at map when they first see it...60 secs on day 1 and know that the blue lines are consistent with what they raced on last week and they meet a standard.

Maybe Im missing the point?..and the controls.  ;)   All I want to know is if 1:15000 is 20mm and that is 300m what is 1:10000 and 1:20000 being most used scales.

oh yes sorry, maybe I missed the point. 1:15000 means 1 cm in the are 150 m in nature. So the spacing in the maps is 300 m at 1:15000 and 200 m at 1:10000 m. But also a novice should be able to think about the scale. 1 cm is ... m. I never use the blue lines to know how far to go but I estimate the distance on the map. Most compass have a scale so you could even measure.

The rules say as michi said: 20 mm independent of the scale. So official international maps should have this standard.

Cheers,
Anke  

--Last edited by nordlicht_anke on 2008-10-12 17:14:04 --

I think there is no need so many mag. north-lines. The pace between those lines shold be 5 cm.