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<div class="moz-cite-prefix">On 23/3/20 9:08 am, Volker Schmidt
wrote:<br>
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<div dir="ltr" class="gmail_attr">On Sun, 22 Mar 2020 at
19:09, François Lacombe <<a
href="mailto:fl.infosreseaux@gmail.com"
moz-do-not-send="true">fl.infosreseaux@gmail.com</a>>
wrote:<br>
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<div>Hi Volker,</div>
<div>...<br>
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<div>Fully disposed to make any improvement to wiki
according to those points.<br>
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<div>Thanks, Francois.</div>
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<div>There is possibly a language bias (error?) in the use of
tunnel=flooded.</div>
<div>I am not a native speaker, but "flooded" to me means at
least "more water than normal", and from this discussion it
seems that we are talking about the normal presence of water
in these structures.</div>
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<p>Normal? No I don't think so. Some 'tunnels may be designed only
to carry water and have no real room for anything else. I am
thinking of hydo schemes where tunnels are used<br>
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<p>To me 'tunnel=flooded' means that is cannot really be used for/by
anything other than the fluid in it due to the very small amount
of space left, if any. </p>
<p>Humm ... a smaller description? '"tunnel=flooded' ... full or
nearly full of fluid so that the tunnel cannot be used for
anything else' ??? <br>
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<div>Tag use tunnel=flooded: 2 in the UK, <br>
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<div>>> Many, if not the majority of the UK Inland
Waterways canals have no tow-path.</div>
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<div>> Then tunnel=flooded is more appropriate.</div>
<div>No, definitely not. These tunnels are not "flooded" at
all, the water level in them is carefully controlled <br>
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<div style="margin-left:40px">(The original method of
powering the boats in these canals were men laying on
their back and "walking" with their feet upwards along the
tunnel ceiling. The French canals, being constructed
later, generally did have tow-paths also in the tunnels
see for example the <a
href="https://www.google.com/url?sa=i&url=https%3A%2F%2Ffr.wikipedia.org%2Fwiki%2FTunnel_de_Mauvages&psig=AOvVaw3UK-_RmcKBM_5fKTGMZyjW&ust=1584997257128000&source=images&cd=vfe&ved=0CA0QjhxqFwoTCOijlIn9rugCFQAAAAAdAAAAABAS"
moz-do-not-send="true">Tunnel_de_Mauvages</a>. I
remember when I was a boy my father showed me the tractors
pulling the ships through the old tunnel near Arzwiller in
Alsace on the same canal)<br>
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<div>They are uniformly tagged (correctly) as waterway=canal
and tunnel=yes.</div>
<div>I mentioned them in the context that tunnel=yes does
not imply a tow-path. <br>
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<div>I had glanced at your<font size="2"><span
style="font-weight:normal"> Hydropower water supplies</span></font>
proposal, but I think I failed to intervene on three
specific points:</div>
<ol>
<li>The first one are the inverted siphons (<a
href="https://it.wikipedia.org/wiki/Botte_sifone"
moz-do-not-send="true">botte sifone</a>, <a
href="https://fr.wikipedia.org/wiki/Pont-siphon"
moz-do-not-send="true">pont-siphon</a>), which are
gravity-pressurised always-water-filled sections of
non-navigable canals. I usually map them as culverts,
and i have just started to add the new tag
culvert=inverted_siphon to the first three of them.</li>
<li>The second point is that the distinction between
water-filled and part-filled water conducts is
problematic: culverts that are frequently used to
conduct free-flowing drains, ditches, irrigation canals,
freshwater canals under roads can be anything from empry
to fully filled (and slightly pressurised) depending on
precipitations.</li>
<li>waterway=pressurised cannot be used together with
waterway=canal for the inverted-siphon situation</li>
</ol>
<div>Volker<br>
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