Proposal:Suction Point Refinement

NOT YET READY - FIRST DRAFT

Suction Point Refinement
Proposal status:	Draft (under way)
Proposed by:	OsmHydrant
Tagging:	emergency=suction_point Data item
Applies to:
Definition:	Refinement of emergency=suction_point in contrast to non-pressurized emergency=fire_hydrant, emergency=water_tank or emergency=fire_water_pond
Statistics:
Draft started:	2019-03-24

Proposal

This proposal wants to change tagging when it comes to emergency=fire_hydrant + fire_hydrant:pressure=suction. In such taggings you have to use a fire-engine to pump off water similar to emergency=suction_point. In addition this proposal aims at clarifying the emergency usages of emergency=water_tank and emergency=fire_water_pond.

My suggestions are based on recent work on the emergency=fire_hydrant wiki page.

TL;DR

• deprecate fire_hydrant:pressure=suction (and fire_hydrant:type=suction_point), but instead:
  • enforce emergency=suction_point with couplings (and/or couplings:type, couplings:diameters)
• deprecate emergency=water_tank, but instead:
  • enforce man_made=storage_tank + content=water
  • and nearby: emergency=suction_point + water_source=water_tank + water_volume
• deprecate emergency=fire_water_pond, but instead:
  • enforce natural=water + water=pond
  • and at appropriate place(s): emergency=suction_point + water_source=pond (+ water_volume)

Rationale

Favor suction-points over fire-hydrants

The tag emergency=fire_hydrant + fire_hydrant:pressure is usually assigned a numeric value in bar. Sometimes it might also have the values yes, or suction. I propose to get rid of these usages by favoring an emergency=suction_point + couplings (and/or couplings:type, couplings:diameters).

Current usage of fire_hydrant:pressure:

	<all>
	yes
	suction

Main reason: The expectation of a fire-fighter is not met. With fire-hydrants you do not need a fire-engine to get to water. Instead you just turn "on" the fire-hydrant since the water source is pressurized. If the object is tagged as suction-point, you know upfront that you need a fire-engine. Depending on the additional presence of couplings-tags, fire-fighters know if they need to prepare appropriate materials like a suction-basket. So anybody looking for emergency=suction_point knows to bring the appropriate material to deal with it (like pumps, baskets, pipes, etc.).

More reasons:

• The notion of emergency=suction_point for a preferred place to pump off water is fulfilled (even when it got prepared couplings).
• Not every fire-fighting facility with couplings is a fire-hydrant. Think of emergency=dry_riser_inlet.
• The multi-value usage of fire_hydrant:pressure is currently misleading, whereas having only numeric values (with units) would ease the emergency=fire_hydrant tagging schema.
• An additional water_source tag will specify if the water volume is unlimited.

Similar reasoning applies against the non-standardized fire_hydrant:type=suction_point. Previously fire_hydrant:type=pond has been deprecated in favor of water_source=pond, since pond is just the water supply, but not the physical delivery mechanism like (pillar/underground/wall).

Current fire_hydrant:type=suction_point usage:

Favor suction-points over water-tanks/fire-water-ponds

Water-tanks and ponds are often tagged within the emergency namespace. Since you always need appropriate materials like a fire-engine to pump off water, I suggest deprecating their use and go for emergency=suction_point instead.

Water-tanks can be tagged as man_made=storage_tank + content=water. In a similar fashion ponds can be tagged as natural=water + water=pond. If their water can be utilized by fire-departments, an emergency=suction_point clarifies that you need a fire-engine to get to water.

Such water-sources often serve additional purpose and is not exclusive to fire-fighters. For this reason a separate emergency=suction_point would result in a clear tagging schema.

In both cases a water_source tag with values like water_source=water_tank or water_source=pond clarifies what to expect. If the amount of water is limited, water_volume may be useful.

Currently the emergency=water_tank wiki page is misleading since it shows open (not covered) fire-water-ponds. Within Wikipedia there is not a single water-tank that is open. In each case the water-tank should be described in my opinion without emergency tag and a emergency=suction_point node should be put nearby.

Examples

TODO

Tagging

The resulting wiki page for emergency=suction_point would look like:

A preferred point to pump water off a source for a fire department using appropriate material. It is designed to fast get access to water for extinguishing a fire.

Optional tags (taken from emergency=fire_hydrant

• Couplings:
  • couplings: number of couplings
  • couplings:type: coupling standard like Bayonet, etc.
  • couplings:diameters: 110mm
• Source:
  • water_source: like stream, canal, drain, pond, lake, water_tank, etc.
  • water_volume: if its not unlimited like with rivers and lakes, this can be set to state its restriction (e.g. "150 m³")

Further tags:

• layer: e.g.: "-1" if its an underground canal
• suction_lift: new property to specify the height of suction in meters

Features/Pages affected

Tag	Occurrences
emergency=suction_point
emergency=fire_hydrant
fire_hydrant:pressure=suction
emergency=water_tank
emergency=fire_water_pond

Comments

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