Proposed features/Fire Hydrant Extensions
|Fire Hydrant Tagging Extensions|
|Status:||Proposed (under way)|
|Definition:||additional information for emergency=fire_hydrant|
- 1 Rationale
- 2 Proposal
- 3 New Tagging
- 4 Examples
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.
American Water Works Association colour scheme
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 bonnet and caps of a fire hydrant. In other cases, finding out the capacity may be more difficult.
|Class||Flow Capacity||Bonnet & 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|
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.
Here is the new proposed tagging for a fire hydrant, for numeric values with units, see the guidelines: Map Features/Units
|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, stream, 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. The caps are the covers over the hose openings.||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||See below for reference|
Revisions to fire_hydrant:type
Fire_hydrant:type in its current form improperly conflates two concepts, the water supply and the physical delivery mechanism.
fire_hydrant:type=pond will be deprecated because it will be replaced by water_source=pond.
Three new values, fire_hydrant:type=pipe, fire_hydrant:type=dry_barrel, fire_hydrant:type=wet_barrel will be added.
|pipe||An hydrant consisting of a simple capped pipe.|
|pillar||A pillar type hydrant. Use this value if you don't know if it's a dry or wet hydrant. Otherwise read below dry_barrel and wet_barrel.|
|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. The type may be determined by inspecting the caps; they are usually arrayed at the same level as there is no corresponding valve inside the hydrant barrel.|
|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 temperate climates, but not used wherever the temperatures may be consistently below freezing. The type may be determined by inspecting the caps; they are arrayed at different levels as each cap has a valve internal to the hydrant barrel.|
|wall||A wall-mounted fire hydrant.|
|underground||A fire hydrant simple outlet located underneath a metal cap in Germany. Hard to know anything about couplings, whench or sizes without opening the cap|
|fire_hydrant:wrench||pentagonal||A wrench with pentagonal footprint|
|squared||A wrench with squared footprint|
|triangular||A wrench with triangular footprint|
|linear||A wrench with linear or rectangle footprint|
|key||The hydrant is locked with a key needed to open it|
This list can be extended as needed by mappers if they find a different type of lock for hydrants.
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.
A new value, location=tunnel should be used for hydrants inside a tunnel.
For hydrants, locations values should be:
|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|
|tunnel||inside a tunnel|
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.
Values to be replaced
Some pretty used tags should be carefully replaced like suggested below.
It's recommended to check the values of such tags and to not mass edit.
|Obsolete tag||Usage volumetry||Used for||New tag(s) to use|
|fire_hydrant:position=*||296 235 on 2017-08-04||Positioning the fire hydrant in its environment||location=*|
|in_service=no||60 on 2017-08-04||Indicate that fire hydrant is out of service||disused:emergency=fire_hydrant|
|fire_hydrant:couplings:type=*||627 on 2017-08-04||Fire hyrant's coupling typology||fire_hydrant:couplings_type=*|
Surface fire hydrants
|--||A simple raising pipe serving as a fire hydrant outlet with a proper coupling hose at its end.|
|--||On the fire hydrant as a node||A standalone fire hydrant fed by a 20 m3 pond located just underneath the ground. It's not connected to water system but only to the pond.|