Proposed features/Fire Hydrant Extensions

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Fire Hydrant Tagging Extensions
Status: Proposed (under way)
Proposed by: nfgusedautoparts
Tagging: emergency=fire_hydrant
Applies to: Node
Definition: additional information for emergency=fire_hydrant
Drafted on: 2013-03-09
RFC start: 2017-06-17
Vote start: -
Vote end: -

Some Extensions to support fire_hydrant

Proposal

Some subtags in support of fire_hydrant are described. These tags contain detail about fire hydrants that have considerable value to First Responders. This proposal additionally proposes deprecating one value for fire_hydrant:type and adding two tags for fire_hydrant:type. Some new variations on fire_hydrant are included, as are new variations of colour. The meaning of colour as applied to fire_hydrants is formally defined, and additional colour subtags are proposed which cover common cases of hydrants painted in more than one colour.

Rationale

Projects are in progress which aim to use OpenStreetMap to support First Responders. These tags are intended to support those projects by providing details about hydrants above and beyond those which are captured by the existing tagging scheme. Some of the data may be discerned from a physical survey of individual hydrants, and other data may be available from public databases. The most likely scenarios for First Responder use of OSM data are "mutual assistance" calls, where a responder travels outside their normal area of responsibility and as such knows less about local conditions than normal.

Background

Wet Hydrants are generally fed by water mains in urban and suburban areas. The dimensions of the mains vary greatly, and so the flow capacity of the hydrants can vary substantially. The location of hydrants is the first requirement in a mutual assistance call; the second most important piece of information is the flow capacity. Some jurisdictions in the United States have adapted a colour scheme specified by the American Water Works Association. In these jurisdictions, flow capacity may be determined simply by examining the colour of the top and caps of a fire hydrant. In other cases, finding out the capacity may be more difficult.

Flow Capacities and AWWA Colour Scheme
Class Flow Capacity Top & Caps Colour
AA more than 1500 gpm Light Blue
A between 1500 and 1000 gpm Green
B between 1000 and 500 gpm Yellow
C less than 500 gpm Red

Revisions to fire_hydrant:type

Fire_hydrant:type in its current form improperly conflates two concepts, the water supply and the physical delivery mechanism. I propose that type pond be deprecated, and three new values be added:

New values for fire_hydrant:type
Value Description
pipe delivery via a simple capped pipe. Most dry hydrants use this method
dry_barrel a style of pillar hydrant where the water shutoff valve is below ground, hopefully below the frost line. These are used on pressurized systems where freezing is a risk. They are occasionally used for dry hydrants when the water supply is higher in altitude than the hydrant.
wet_barrel a style of pillar hydrant where the barrel is pressurized at all times, with individual valves for each outlet. These are common in Southern California.

Migration from fire_hydrant:position=* to location=*

The key location=* is already used in other contexts and indicates the same concept. Therefore current values of fire_hydrant:position should go in location.
For hydrants, locations values should be:

Values for location
Value Description
lane on the side of a road lane (but not on a sidewalk)
parking_lot in a parking
sidewalk on a sidewalk
green on a green area

Migration from in_service=yes/no to disused:emergency=fire_hydrant

The prefix disused: is already used in other contexts and indicates the same concept. Therefore there is no need of the tag in_service=yes/no.
Hydrants are supposed to be in service by default.
If not, use the tag disused:emergency=fire_hydrant.
To differentiate between hydrants certainly working and hydrants whose functionality is not known, use the survey:date to denote a real functional check.

New Tagging

For numeric values with units, see the guidelines: Map Features/Units

Proposed tags
Tag Description Valid values
fire_hydrant:class in the US, classification per American Waterworks Association. If fire_hydrant:class is present, fire_hydrant:flow_capacity is redundant AA, A, B, C
fire_hydrant:flow_capacity minimum flow capacity. If fire_hydrant:class is present this is redundant numeric value with unit, valid are l/min (Liter per minute), gpm (gallons per minute), or m³/h (cubic meter per hour); e.g.: 600 l/min
water_source source of water for hydrant pond, steam, main
survey:date can be used to reflect the last functional check (this tag is not specific to fire hydrants) yyyy-mm-dd
colour the colour of the hydrant. Unless otherwise specified, the entire hydrant is this colour
colour:bonnet colour of the top section ("bonnet") of the fire hydrant if different from the colour tag value blue, green, yellow and red are the valid values in the AWWA scheme, but many jurisdictions do other things.
colour:cap colour of the caps of the fire hydrant if different from the colour tag value.ì blue, green, yellow and red are the valid values in the AWWA scheme, but many jurisdictions do other things. If caps are painted in more than one colour, list all colours separated by semicolons.
colour:reflective color of reflective material, if any (commonly stripes or bands around the barrel.)
fire_hydrant:couplings:type coupling standard Baionetta, Barcelona, Guillemin, Klaue, Sprawny, Storz, UNI

More types are described at: https://en.wikipedia.org/wiki/Hose_coupling

fire_hydrant:couplings:size each coupling diameter, separated by semicolons #;#;# (standard unit is mm, otherwise specify it. For inches use "). In some countries characters A, B, C are used to specify the connector (Austria)

e.g.: taken this image & guessing diameters, this could result in: 110;45;45

fire_hydrant:wrench type of wrench needed to open the hydrant pentagonal, square, triangular, linear