Proposed features/Lines management

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Lines_management
Status: Draft (under way)
Proposed by: Fanfouer
Tagging: line_management=*
Applies to: node
Definition: Qualify power or telecom supports where lines branch, transpose, split or cross
Drafted on: 2019-10-15
RFC start: 2019-10-26

This proposal is the second one about the tower:type key cleaning.
You may be interested to read more about it

Proposal & rationale

Line management is about the how lines are arranged on a given support. They can branch, cross, split or their wires can transpose.
Here are some definitions in use in power domain, useful to define some terms and values of this proposal

  • Branch line (601-02-10) : A side line connected to a main one to feed some consumers hard to reach with main network
  • Transposition (466-05-10) : A change in the conductor/bundles configuration of a line. The transposition may be intended to preserve grounding or interference conditions (power/telecom lines)
  • Termination (461-10-01) : End part of a line intended to properly ensure safety and insulation on a point of connection on a dedicated support.

OSM currently describes the management of power lines mainly with multi-purpose key tower:type=*. The same key is used to make the difference between a castle and a telecommunication towers based on their structure and material. This is inconsistent and less usable.
This information is useful for telecom wires too. Then it's more appropriate to deal with standard cable management terms and share those concepts without specialised terminology for each domain.
It is proposed to use a new line_management=* key to free tower:type=* and pole:type=* from defining how lines are arranged. This would allows us to keep tower:type=* to define towers shape and to extend line management concepts to other kind of supports like poles, portals or even terminal anchors. Current available tagging describes those situations globally without any specific terminology regarding power nor telecom. This proposal is mainly usable for utilities networks and this work could easily be extended with more specific terms or be used for other fields of knowledge also with further proposals.
Among other things, current tower:type=crossing is used to describe individual towers designed to make lines crossing large obstacles like rivers. As it's not a matter of topology nor proper line management, it's proposed to move it through height=* and design=* which give a better description for such infrastructure.

Simple supports with no particular line management situation aren't supposed to get line_management=* key.

Concrete benefits

  • Share equivalent concepts between many fields of knowledge (power, telco, cable transport / towers, poles, masts, terminal and portals) and provide to mappers a common set of terms matching what they will actually see on the field.
  • Ability to describe on the same feature how lines are arranged and simultaneously how they are attached (with line_attachment=* without get stuck on domain specific terminology.
  • Split according values to a dedicated key and free tower:type=*, pole:type=* with less related values. Prevent the definition of same kind values to :type keys.

Tagging

Values are similar to current tower:type=* associated with power=tower

Picture Key/Value Description
Line anagement branch.png line_management=branch A side line going in a different direction connects to a main one on a support.

It includes situations where a branch underground cable connect to the main overhead circuit with location:transition=yes help (and vice versa).

Line management split.png line_management=split Two or more distinct lines split apart towards different paths. Incoming circuits have to come from the same origin.

It includes situations where some of the incoming circuits goes underground with location:transition=yes help.

Line management transpose.png line_management=transpose The conductor bundles arrengement changes on a given support
Line management cross.png line_management=cross This value indicates there is no connection between two or more lines sharing a given support. It prevents the use of things like connection=no.
Line management loop.png line_management=loop A patch is connecting several independent line systems coming from the same direction. This is in use on power systems as to maintain one of them under network voltage for monitoring purpose while disused (no power transit).
Management termination.png line_management=termination A termination implies one or more lines are anchored on a given support with no connection between them.

A support with location:transition=yes, connecting an underground cable to one of the incoming overhead lines is not a proper termination.

Transition supports aren't terminations

It is assumed that a support connecting an underground cable to an overhead line isn't a proper termination for sake of consistency with split and branch definitions.
If such support were terminations, aerial to underground split and branch can't exist and the support should be described with line_management=--no_value_for_straight_line--|termination which is not desirable.
Transition supports souldn't get any line_management=* value.

Use cases

Let's illustrate this proposal with a concrete usecase summarizing many individual possibilities.
Further thinking is required to address complex situations, as line management can mix several configurations on different tower levels.
Once a little more work will be done on Matrix_values, proposed values for line_management=* could be used together to better reflect situations occuring on the same tower/pole support node.

You'll find below a chart illustrating what you shoud see on ground and how to use corresponding line management values.

Power line chart pole termination.png Termination pole

power=pole
line_attachment=anchor
line_management=termination
Power line chart pole loop.png Loop pole

power=pole
line_attachment=anchor
line_management=loop
Power line chart pole split.png Split pole

power=pole
line_attachment=anchor
line_management=split
Power line chart pole branch.png Branch pole

power=pole
line_attachment=(pin)|(anchor)
line_management=branch
Power line chart pole cross.png Cross pole

power=tower
line_attachment=(pin)|(anchor)
line_management=cross
Power line chart tower transpose.png Transposition tower

power=tower
line_attachment=anchor
line_management=transpose

Edition management

Affected pages

Values to be replaced

Obsolete tag Usage volumetry Used for ? New tag(s) to use
tower:type=branch ( + branch:type=tap) 1721 on 2019-10-15 A side anchored line connect to the main one line_management=branch
tower:type=branch ( + branch:type=split) 2616 on 2019-10-15 Two or more independant circuits continues in different directions line_management=split
tower:type=branch ( + branch:type=cross) 286 on 2019-10-15 Two or more independant circuits share a common support without connection line_management=crossing
tower:type=branch ( + branch:type=loop) 123 on 2019-10-15 Two or more independant circuits are connected in the same direction to maintain a dead part of the network under a positive voltage line_management=loop
tower:type=termination 5017 on 2019-10-15 The line ends on a dedicated support line_management=termination
tower:type=transposing 536 on 2019-10-15 Conductors or bundles configuration or position change line_management=transpose
tower:type=crossing 1369 on 2019-10-15 A support is significantly higher and stronger to allow a line to cross an obstacle like rivers height=* + design=*

A whole total of 11 600 objects have to be edited, which doesn't sound so important regarding the 10 millions power towers in OSM and the potential of telecom or misc supports remaining to map worldwide

Examples

Power

Photo Location Tagging Note
Transposition with anchor attachment Germany

power=tower
line_attachment=anchor
line_management=transpose

A classical power conductor transposition with help of anchor attachment
Actual split with anchor attachment Germany

power=tower
line_attachment=anchor
line_management=split

Four splits on two separate towers. If you look at connection, you'll see there is no Y connection and it's only independent power systems that change of direction
French 400kV tower hanging insulators.jpg France

power=tower
line_attachment=anchor
line_management=branch

A side line connects to the main one (the presence of hanging insulator in the red circle doesn't affect this line management situation)
Power portal substation transition.jpg France

power=insulator
line_attachment=anchor
line_management=termination

The concrete portal should be mapped as a way and the line should connect to it on a power=insulator node. Although a bay line (inside the substation) connects to the incoming line, it's a termination from the management point of view
A termination with a transformer France

power=tower
line_attachment=anchor
line_management=termination

A medium voltage power line terminates on a concrete pole to connect to a distribution transformer

Telecoms

Photo Location Tagging Note
Canada telecom pole branch.jpg Canada

telecom=pole (Theoretically)
line_attachment=(suspension)|(anchor)
line_management=branch
material=wood

Let's focus on telecom lines only here.


The main line goes from left to right and is suspended on the pole while a branch line starts from its anchor.
On this location, power and street lighting utilities are also installed and branch too.

See also

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