Talk:Tag:waterway=canal
Discuss Tag:waterway=canal here:
Lock gates
How are we tagging lock gates then? waterway=lock_gate is already on map features. So the mention of other suggestions here (man_made=lock, lock=*, lock:name=*) is confusing. If waterway=lock_gate is the accepted way to do it, then we'll need to specify whether it's a single node or a length of way which was otherwise canal. (Should have these details on the Tag:waterway=lock_gate page) -- Harry Wood 12:46, 6 May 2008 (UTC)
- I tag locks (on small, UK-style waterways) as nodes with lock=yes. A lock de facto has gates at each end, it wouldn't work very well otherwise. --Richard 14:51, 6 May 2008 (UTC)
- I've been tagging locks as a short segment of waterway=lock with a node tagged as waterway=lock_gate at each end. The name and number of the lock go on the name= tag for the lock section. Seems to render nicely e.g. http://www.openstreetmap.org/?lat=53.709395&lon=-1.905365&zoom=18&layers=B0FT
- --POHB 08:13, 7 May 2008 (UTC)
- hmmm. Two different ways of doing it then. -- Harry Wood 16:20, 7 May 2008 (UTC)
Width
Can a width tag be applied to a canal? I'm asking because an irrigation canal that is about three meters wide is being rendered the same width as a two-lane road. — Val42 05:00, 4 October 2008 (UTC)
Width (in metres) can be added to denote the average width of a canal: width=3 in your case.
maxwidth=* can be used to define the maximum beam of boats able to use the canal which will be determined by pinch points such as aqueducts, bridges and locks. For a canal it probably makes sense to apply it to the whole length given that boats won't be able to travel from end to end because of the beam restrictions. On a navigable river with locks however, it is probably more logical to only apply it to nodes or short sections where there is a width restriction, i.e. a lock channel.
Usage
I'm not clear about usage how and for what. We've a canal (Rhine–Main–Danube Canal) here which is about 55 metres wide. But it's narrower e.g. when bridging over streets or before locks and has dents on some places. So it's not possible to get that width and shape right with a line taged as waterway=canal. Also it has tracks attached to both sides which should be done right.
It looks good as poligon tagged as natural=water or waterway=riverbank but that's semantically wrong. So what to do here? I've seen such canals done as a polygone tagged as waterway=riverbank and a path in the middle tagged as waterway=canal. Is that a standard and state of the art?
And what is waterway=canal really for then? --Miriat 15:15, 19 November 2008 (UTC)
