[Tagging] Fire hydrants vs suction_point

Fran├žois Lacombe fl.infosreseaux at gmail.com
Sun Aug 20 23:04:53 UTC 2017

Hi Viking,

Thank you for synthesis and proposal update.

2017-08-20 2:02 GMT+02:00 Viking <viking81 at tin.it>:

> Francois, as a firefighters, I can say that it's very very important to
> distinguish a pressurized hydrant from a dry hydrant (or suction point).
> And we all agree.
> And now I explain the reason why I prefer this distinction in the primary
> key.
> First of all in many cases you don't know the pressure, but you know only
> that it's a pressurized hydrant. You should use something like
> fire_hydrant:pressure=positive that adds complexity and it's error prone
> for an inexperienced mapper.

I agree with you for fire_hydrant:pressure=positive complexity.
water_source=mains or water_source=network may be enough

The point isn't to know exact pressure, only source is a concern for us.

> Then, for my fire departement, I've extracted hydrants data from OSM, I've
> uploaded it on some old and new GPS and I've sent it on my colleagues
> smartphones.
> The simplest (and in many case the only) way to tranfser hydrants
> attributes to GPS is to put them in waypoints names. But waypoints names
> lenght is limited in GPS, so it's likely that someone transferring data
> will loose the fire_hydrant:pressure information.
> Then it's simpler to look for emergency=fire_hydrant or
> emergency=suction_point than look for emergency=fire_hydrant +
> fire_hydrant:pressure=positive or emergency=fire_hydrant +
> fire_hydrant:pressure=suction.
> In conclusion grouping different items under the same primary key and,
> even worse, grouping all water sources under emergency=water_source, adds a
> not necessary complexity in data managament.
> Simpler is always better. In this case it is simpler to keep
> emergency=fire_hydrant for pressurized hydrants and emergency=suction_point
> for all other non pressurized water sources.

I'll follow you on tagging simplicity and stop argue on grouping under

If we take this way, it may be really good to add water_source on both
emergency=fire_hydrant and emergency=suction_point.
Even if an hydrant is always pressurized, it can be fed by a private water
grid. Then we have at least 2 sources : mains and private_network (or

For sake of simplicity, fire_hydrant: and suction_point namespaces should
be avoided as done for fire_hydrant:position
Since all hydrants will have emergency=fire_hydrant, some keys can be
fire_hydrant:wrench => wrench (and automatically make it available for
suction_points also)
fire_hydrant:type or suction_point:type => fire_hydrant or suction_point

To follow Moritz logic for pillars, pillar=dry_barrel or wet_barrel is

> For suction point another proposal of refinement is needed.

Not sure on this point if grouping under a single emergency=* value is
Both features have keys in common.

All the best

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