Nathan Edgars II wrote: > I'm trying to do something like the European tagging: > http://www.itoworld.com/map/24 > But there they have some sort of international treaty that > defines configurations.
(puts day-job hat on) For users of a waterway, the European (CEMT) waterway classes describe, rather than define, the size of the limiting structures. They're information, rather than regulation. In other words, although a class Va waterway has a stated length of 110 metres, that doesn't mean that a river policeman will come and flag you down for taking a 115m boat along the river. It's very possible that the locks are (say) 120m long, and if you can get your boat through them, you're absolutely entitled to do so. This is particularly important at the smaller end of things where locks and bridges may be a zillion and one different sizes. (Here in Britain people routinely build boats to 60ft because there are certain locks that are 58ft 6in long... and if you put the boat in the lock diagonally, you can squeeze that little bit of extra accommodation. There are other locks that have subsided to become 1in too narrow for certain historic craft that would once have used the locks. And so on.) So the ideal is to tag each structure with its limiting dimensions, using the familiar maxwidth=/maxheight=/etc. tags. This is never going to be completely achieved, of course, because draught varies for each bit of the riverbed. ;) The next best thing is to tag the 'gauge' of a waterway - in other words, the largest dimensions that will fit through all the structures on that waterway. In Europe, tagging a waterway with the CEMT class would be a quick-and-dirty-though-not-particularly-accurate way of stating the gauge. (That said, the CEMT class would fit very well in the designation= tag.) cheers Richard -- View this message in context: http://gis.19327.n5.nabble.com/U-S-inland-waterways-tp5709017p5709046.html Sent from the USA mailing list archive at Nabble.com. _______________________________________________ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us