[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
emergency=water_supply.

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
similar)

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
lightened
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
enough


> For suction point another proposal of refinement is needed.
>

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


All the best

Fran├žois
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