[Tagging] Fire hydrants vs suction_point

[Moritz]

Hi François, hi Alberto,

we had in the past days a discussion on the german OSM forum[3] and 
agreed on the point that
a point where you can suck water from a water source is a 
emergency=suction_point.
Our understanding of a fire hydrant is, that it is connected to a water 
main and thus any
suction point is no fire hydrant.

The special case of commercial area where the owner is responsible for 
the hydrants and the hydrants are fed by
pumps from ground water or by tanks were not discussed (as Viking81 
wrote on the discussion pages of [1] and [2]).

As I am a firefighter by myself I think there is such thing, but I will 
figure out with the local fire department.

We furthermore agreed that there is no need of my newly proposed tag 
emergency=fire_water_well as we can define
the different types of suction points by adding appropriate tags for 
each type.

> My point is suction points and fire hydrant are different but 
> compatible things, as follow :
> emergency=suction_point is a prefered place where to pump water in a 
> river
I think you meant from a river. But yes I agree.

> emergency=fire_hydrant
> is a kind of device which may or not be present in places like suction 
> points but in a large amount of other places.

Nope.
Fire hydrant: pressurized water from water main. Edge case of Vikings 
point not yet covered

>> Hydrants that serve factories or shopping centers often are not 
>> connected to the public water main:
>> instead they are connected to a private local water network fed by 
>> pumps that suck water from the ground.
>> So these local water networks and their hydrants are fed by what we 
>> can call water wells.

Suction points

Points where the firefighter have to bring there own pump to suck water 
from pond, river or well.
These suction points can be equipped with a pipe connected to the water 
or not. Something like this with pipe [4][5][6].

Or this [7][8] which also is a suction point, which can has a sign. But 
basically it's just an somehow prepared point to have
easier access to the water itself.


> 
> We need to know if the common accepted definition of suction point is 
> this:
> 
> Suction points aren't devices like hydrants but are preferred places
> to pump water from a not pressurized water source (river, pond, well).

Yes

> Hydrant is an equipment/device and suction point is a place where you
Yes

> may or not find a hydrant.
No. I would not call a pipe at a suction point hydrant (lack of 
pressured water).
At least from my German point of view, because here pipe and hydrant 
look different.

> In this case the hydrant will be tagged emergency=fire_hydrant +
> fire_hydrant:pressure=0.

Nope, because then you have emergency=fire_hydrant but you have to bring 
your own pump to get water. To be sure you have to
evaluate the fire_hydrant:pressure tag to determine what it is.


Here is the outcome of the discussion in the German forum:


# Suction point with pipe at a lake, river, stream etc (like [5])

emergency=suction_point
suction_point:source=water
suction_point:position=lane|parking_lot|sidewalk|green


# Suction point at fire_water_pond (artificially created pond, otherwise 
it is the above one)

emergency=suction_point
suction_point:source=fire_water_pond
suction_point:volume=# (volume in m^3)
suction_point:productivity=small|medium|large|#  (small: 400-800l/min, 
medium: 800-1600l/min, large: 1600+ l/min; l/min)
suction_point:position=lane|parking_lot|sidewalk|green

# Some prepared suction place at  lake, river, stream etc, but without a 
pipe (like [8][7])

emergency=suction_point
suction_point:type=suction_place
suction_point:source=water

# Suction point at water_tank

emergency=suction_point
suction_point:source=water_tank
suction_point:volume=small|medium|large|# (small 75–150 m^3, small 
150–300 m^3 und large>300 m^3; volume in m^3)
suction_point:productivity=small|medium|large|#  (small: 400-800l/min, 
medium: 800-1600l/min, large: 1600+ l/min; l/min)
suction_point:position=lane|parking_lot|sidewalk|green


# Normal fire water well

emergency=suction_point
suction_point:type=fire_water_well
suction_point:productivity=small|medium|large|#  (small: 400-800l/min, 
medium: 800-1600l/min, large: 1600+ l/min; l/min)
suction_point:position=lane|parking_lot|sidewalk|green
fire_water_well:type=suction
fire_water_well:water_level=# (distance water level-ground)

# Fire water well with integrated pump (electric or water driven pump)

emergency=suction_point
suction_point:type=fire_water_well
suction_point:position=lane|parking_lot|sidewalk|green
suction_point:productivity=small|medium|large|#  (small: 400-800l/min, 
medium: 800-1600l/min, large: 1600+ l/min; l/min)
fire_water_well:type=bilge_pump|electric_pump

With this tagging scheme there are still some issues:

For productivity tag I just copied from the German standards.

In case of a water_tank the volume belongs technically to the water_tank 
itself
but not to the suction point. But I think it is more convenient because 
as water_tanks
are usually hidden under ground they are not as visible as suction 
points. So I
assume they will be not mapped as often as suction points. Other point: 
to get the volume
  information of the suction point you have also to check the next 
water_tank. Seems inconvenient.


For the special case hydrants on commercial area sourced from pumps or 
water_tanks I would go for hydrant. Because
the whole thing behaves more like a hydrant then a suction point (at 
least as long the tank is not empty or the wells
are not exhausted).

Why is a water well with an integrated pump not a hydrant:

Special case of water well. And firefighters expect from a hydrant that 
they just have to connect there hose and get water easily.
With the well with integrated pump you have to keep in mind that you 
have to bring a pump or a generator.


I would suggest, that we discuss all stuff here, not on the wiki 
discussion page as long as no new participant shows up.
Mailinglist is easier to use.


Cheers,
Moritz


[1] 
https://wiki.openstreetmap.org/wiki/Talk:Proposed_features/Fire_Hydrant_Extensions
[2] 
https://wiki.openstreetmap.org/wiki/Talk:Proposed_features/Fire_water_well
[3] https://forum.openstreetmap.org/viewtopic.php?id=59352
[4] 
http://www.feuerwehr-satow.de/typo3/uploads/pics/30012011_saugstelle.jpg
[5] http://home.teleos-web.de/fschubert4/gfx/Bild%20Saugstelle2.jpg
[6] 
https://wiki.openstreetmap.org/wiki/File:French_hydrant_water_pond.jpg
[7] 
http://www.infranken.de/storage/image/5/9/2/8/2498295_cms2image-fixedwidth-900x0_1pbCVs_61CvXH.jpg
[8] 
https://upload.wikimedia.org/wikipedia/commons/thumb/e/e3/Zufahrt_zur_Saugstelle_der_Feuerwehr_in_Herbstein%2C_Vogelsberg%2C_Hessen_-_1.jpeg/1200px-Zufahrt_zur_Saugstelle_der_Feuerwehr_in_Herbstein%2C_Vogelsberg%2C_Hessen_-_1.jpeg