[Tagging] tagging towers WAS Re: tall masts supported by guy wires

[M∡rtin Koppenhoefer]

2010/9/11 Nathan Edgars II <neroute2 at gmail.com>:
> On Sat, Sep 11, 2010 at 5:27 AM, David Groom <reviews at pacific-rim.net> wrote:
>> What's the preferred way of tagging a mast like this
>>
>> http://en.wikipedia.org/wiki/File:Rowridge_from_entrance_gate_200704270010.jpg
>>
>> From memory I had thought it was man_made=mast, but I cant find any mention
>> of that on the wiki.
>>
>> I see on the wiki there is a" man_made=tower" + "tower:type=communication"
>> combination, but I'm not sure the picture above is a  "tower".
>>
>> To my mind a "tower" is something free standing, whilst a mast is a much
>> thinner structure supported by  wires
>
> It's a guyed tower.

a tower is "self-supporting", which might be read as contradictory to
guys (unless you consider the guys being part of the tower itself). I
wouldn't actually tag antennas as towers.

The wiki doesn't help a lot, defining a tower as "A man made tower",
but it indicates in some way that tagging should refer to what is
commonly referred to as a "tower".

There is another issue I found while searching tower:
http://wiki.openstreetmap.org/wiki/Tag:man_made%3Dwater_tower

subtagging might have been appropriate for those as well, at least
they are much more towers than antennas are. (not all tall structures
are commonly identified as towers).

another issue I see with the man_made=tower definition in the wiki is
the construction part which was introduced without any notification
here or discussion (AFAIK)
:
>>>>> tower:construction 	 lattice 	 Node 	 The tower is constructed from steel lattice (most have guy wires)


this is fine beside the "most have guy wires" because
1) that's not true IMHO
2) "most" is not suitable for a definition. Either yes or no or it's
not a criteria IMHO.


>>>>> tower:construction 	freestanding 	Node 	The tower is freestanding 'heavy' construction such as concrete, steel or wood 	  	


this is the basic definition required to be a tower, it is not a
construction principle and not opposed to lattice.


>>>>> tower:construction 	dish 	Node 	The 'communication tower' is a parabolic dish 	  	


is not a tower, but a tower might have dishes attached


>>>>> tower:construction 	dome 	Node 	The 'communication tower' is a dome (or 'golf-ball') construction, with antenna elements concealed from view


the same issue as dish. If it is not a dome supported by a tower but
just a dome this will not be a tower IMHO.


>>>>> tower:construction 	concealed 	Node 	The 'communication tower' is concealed/disguised (for example: made to look like a tree).


IMHO not a construction type either. What about masquerade=yes or
something similar?

I'd like to see different subtags here: purpose/usage and construction
type, construction time, shape, construction style (gothic, baroque,
rationalist, neo-traditional, renaissance, futurist, industrial (this
is of course a generalization, but can help the normal mapper and
could be further refined by specialists) ...)

Purpose:
there are church towers, bell towers, watch towers, towers in city
walls (and gate-towers in specific), towers in castles (regional
differences, e.g. http://en.wikipedia.org/wiki/Bergfried ) , towers in
town houses (e.g. in medieval cities), skyscrapers (might not be
desired here, let's discuss it), defensive towers (different types:
inside a wall/part of a fortress, or freestanding, used as support for
anti aircraft cannons or normal cannons (
http://de.wikipedia.org/w/index.php?title=Datei:Kufstein_burgen.jpg&filetimestamp=20060417221241
) or bowmen, or...), towers as support for restaurants, viewing
platforms, antennas, ...), and lots of others
there are also various kinds of industrial towers (e.g. cooling towers, ...)

construction types:
lattice (steel, wood, plastic/fibreglass, concrete(?))
"solid" ones (masonry, concrete (pre-fabricated or "on the ground one"), wood)
...

Shape:
regarding the bottom/support:
rectangular
circular
hexagonal
octagonal (e.g.
http://de.wikipedia.org/w/index.php?title=Datei:Neunkirchen-am-Brand-St.-Michaelkirche-Turmspitze.jpeg&filetimestamp=20050606154539
)
polygonal (other amount of polygons, probably the better approach,
polygonal and corners=8 instead of octagonal)
other

regarding the top (tower:top):
tower:top=cone (e.g.
http://en.wikipedia.org/wiki/File:Round_tower,_Glendalough.jpg )
pyramid (e.g. http://de.wikipedia.org/w/index.php?title=Datei:Schlieren_Gaswerk_Turm-2.jpg&filetimestamp=20060901154641
)
sphere/dome (or modern multipolygonal "sherized" constructions)
flat (e.g. http://en.wikipedia.org/wiki/File:UCSBStorkeTower.jpg )
onion_dome (e.g. http://en.wikipedia.org/wiki/File:Kostroma_resurrection.jpg )

regarding the base (tower:base) above ground.

regarding the foundation (tower:foundation) below ground / at ground level

regarding the shaft (might be assumed that the shaft is what is tagged
without subtags i.e. the "main tower" or the base, but this depends on
how the tower is actually constructed, of how many different vertical
parts it consists)


subtagged:
tower:merlons=yes/no (see here:
http://en.wikipedia.org/wiki/File:Creneau.romain.png and here:
http://en.wikipedia.org/wiki/File:Genova-Castello_Mackenzie-DSCF8928.JPG
)
tower:top:sign=yes/cross/coat_of_arms/sculpture/...)
tower:top:lantern=yes

As this is really a wide field all those suggested values are just
suggestions and cover only a part of all needed values. Of course you
can also combine subtags like tower:top=cone with tower:top:height=10
tower:top:width=5 (regarding the width at the base of the "top", to be
evaluable there has to be the height of the

I would like to be able to tag something like this:
http://upload.wikimedia.org/wikipedia/de/b/b5/Stundturm_Schaessburg.JPG
or this with parametrical values that allow for three-dimensional
reconstruction as simple 3D-models:
http://upload.wikimedia.org/wikipedia/commons/8/8c/Dom_von_Altenburger_Stra%C3%9Fe_2003-09-22.JPG
which is a rectangular base (quite frequent) and a cone-shaped
"broken" (one corner) top with octagonal "top-base" (locally also
frequent for this time and purpose)

For mapping of towers as parts of buildings I'd suggest drawing the
outline of the base  and attach additionally to the above values
building=part, part=tower (or is there already another approach for
mapping building parts? Maybe the part=tower is not needed, as this is
already clear from the man_made tag). These parts could be combined by
a new relation type building (I don't like to use site because a site
will often consist of more than one building, and by using a dedicated
relation-type it will be less ambiguous and easier to understand for
mappers IMHO).

Sorry for the longish mail. Are there any immediate additions? What do
you think about proposing such a variety of values? Is there a better
approach? Would you support such a proposal?

cheers
Martin