Proposal:Catenary mast details
| detailed catenary mast | |
|---|---|
| Proposal status: | Proposed (under way) |
| Proposed by: | reDoubleYou |
| Tagging: | catenary_mast:*=* |
| Applies to: | 
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| Definition: | Catenary masts support the system of overhead wires used to supply electricity to electrically powered vehicles equipped with a pantograph, such as trams, streetcars, light rail, trains and trolleybuses |
| Statistics: |
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| Rendered as: | hidden, maybe OpenRailwaymap or similar |
| Draft started: | 2024-12-21 |
| RFC start: | 2025-01-02 |
Proposal
Since around 2015 years the tag power=catenary_mast exists with status "de facto". But it is just a node with this tag and without any further informations about the catenary mast. This proposal provides a scheme to add further specifications.
Rationale
Catenary masts are an important element in the area of railway energy supply. OpenStreetMap has not yet recorded consistently any details about these. This is data that is easy to record (on site or by street level imagery) and can enable valuable analyses.
Tagging
Apart from the mandatory and existing tagging of catenary masts by power=catenary_mast, the following tags are proposed for recording details:
construction of catenary mast
It is proposed to describe the construction of a catenary mast with the already existing key structure. There are several designs that can be described directly (tags given in the upper part of the following table). But for other masts, that doesn't fit that tags, there is an generic tagging proposed (tags given in the lower part of the table) to describe the shape and the material with the known and used tag material.
| Feature | Key | Value | Description | Photos |
|---|---|---|---|---|
| construction | structure | mapping by specific design of construction | ||
| lattice | lattice, based on tagging structure | 
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| frame | flat frame masts consist of two U-profiles that are connected with flat steels | 
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| h-beam | catenary masts made of H-profiles or double T-beams (also known as Peiner-masts) | .jpg)
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| trunk | mast made from a tree trunk (means both simply debarked tree trunks and cylindrically milled tree trunks) | 
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| spun | spun poles have a round cross-section, are tapered and hollow on the inside; the production takes place by filling a round mould with a liquid/viscous material (often concrete is used - material can be defined by the tag material=*) while it is being spun and the material hardens | 
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| pipe | round solid steel wall masts | 
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| wall_mount | house wall or wall is used for supporting the overhead contact line, e. g. usual for tram electrification; a point is to map in the edge of the area marking the house (=wall of the house), cantilever or overhead span starts from the wall | 
| ||
| mapping by description of design of construction, specification via mapping of material is recommended - the following tags should only be used if none of the above mentioned tags describing a specific design fit | ||||
| cylindrical | solid masts wit cylindrical or (slightly) conical shape that are not hollow (catenary masts made of a trunk are mapped with the tag structure=trunk described above) | _(2).jpg)
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| polygonal | solid masts with more than 4, but less than infinit (then they would be cylindrical) edges | 
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| rectangular | solid masts with 4 edges, rectangular cross-section | 
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| guyed | yes | only added, if the catenary mast is guyed, default is |
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| catenary_mast:portable | yes | only added, if the catenary mast has no foundation in the ground but is stabilised by huge (concrete) blocks and is thereby portable, often used during time of construction of another infrastruction while the main catenary mast isn't availiable, default is |
unfortunately I haven't (found) a picture yet - if available, please add it | |
Function of the catenary mast
Catenary masts can take the forces of the i. e. overhead contact line in various ways. Mostly, catenary masts support a structure, to that the over head contact line is bound. For this catenary_mast:supporting=* is used. Rarer, the over head contact line is directly attached to the catenary mast itself. For this catenary_mast:attachment=* is used. It is proposed to use following values. In very rare cases, especially at large crossings in city centres, catenary masts can take on several functions. For example, they can span a head span structure with another catenary mast and at the same time hold a cable for lateral support of the overhead line at another point. In this case, the two functions can be mapped in the OSM-way using semicolons to separate both values.
| Feature | Key | Value | Description | Photos |
|---|---|---|---|---|
| Function of the catenary mast | catenary_mast:supporting (if catenary mast supports a structure to that the i. e. over head contact line is bound) |
cantilever | catenary mast supports a cantilever to that the i. e. over head contact line is bound | 
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| head_span | head spans formed between two catenary masts, often in railway stations or in urban areas used for spanning several tracks | 
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| portal | a portal is formed between two catenary masts to which the cantilevers are attached | 
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| lateral | catenary mast takes almost only lateral forces to fix the over head contact line in correct lateral psoition, also called pull-off arrangement | 
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| catenary_mast:attachment (if the over head contact line is attached directily to the catenary mast) |
anchor | the last mast at the end of a electrified track, which takes the tension from the overhead contact line directly in the position of the overhead line, there is no tensioning, the mast is sometimes also located directly behind the buffer stop in the track axis, often tensioning=fix is to be tagged as well | 
| |
| tensioning_only | exclusively for tensioning the overhead contact line; in this case it is recommended to specify the type of tensioning by tensioning=* | 
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tensioning the overhead contact line and midpoint anchor
The overhead contact line does not consist of a single contact wire that runs from the start to the end of the line, but is divided into sections that are up to approx. 1.5 kilometres long. This is for static reasons, as the overhead contact line should always have the same tension, but the length of the overhead contact line (material: copper) changes with the temperature. In addition to their function of holding the overhead contact line, some catenary masts have additional tasks. Some have the task of tensioning a overhead contact line section that is coming to an end. There are different ways of maintaining tension as seen in the table. As well, the midpoint anchor has to be formed by extending ropes starting from the two neighbouring catenary masts as seen in the table.
| Feature | Key | Value | Description | Photos |
|---|---|---|---|---|
| type of tensioning of the overhead contact line | tensioning | weights | Tensioning the overhead contact line with weights |
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| hydraulic | Hydraulic assemblies | |||
| spring | spring | 
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| coil | coiled leaf spring | 
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| fixed | no tensioning, overhead contact line is firmly attached to the catenary mast |
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| yes | if unclear which type of tensioning present or nothing else fits |
electrical equipment
Catenary masts are also used to attach switches for supply lines, couplings or similar items. As well, insulators between catenary and mast are used to separate the potentials. These are usually made of the same material within a catenary mast. It is proposed that this is mapped with the following tags:
| Feature | Key | Value | Description | Photos |
|---|---|---|---|---|
| details concerning switches on the catenary mast ( |
switch | values of switch and switch=yes if unknown | to map a disconnector on the mast and if know the type | 
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| switch:drive | manual | Possibility to flip the switch manually, e.g. using rods on the overhead contact line mast and a lever at the lower end of the mast to flip the disconnector. The device is usually secured against movement with a padlock. | 
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| motor | switch can be flipped by motor, at the lower end of the catenary mast is a box with the motor attached, the motor drives the switch via a system of rods | 
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| switch:ref | <number> | reference number of the catenary mast - caution: do not confuse with the tag ref=* that describes the number of the catenary mast! |
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| Describes default status of this disconnector. But: This tag is not assigned and it is suggested not to use it, as the switching state is described on the element that is jumpered or possible to be jumpered (at least this is how it is done with the already existing and described tag railway:electricity=joint). In order not to have to change the tagging of existing elements, this proposal is adapted to the existing procedure | ||||
| insulator structure | insulator | loop | sling insulators, no shields at the surface, often used for light rail systems and grp as material | 
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| shielded_loop | sling insulators, with shields at the surface, often used for light rail systems and composite as material | 
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| post | sling insulators, with shields at the surface - I think this is the most used for heavy rail systems | 
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cantilever |
the cantilever itself takes the role of insulation too by consisting of an insulating material | 
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| insulator material | insulation:material | glass | for insulators made of glass | .jpg)
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| ceramic | for insulators made of ceramic |
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| porcelain | for insulators made of porcelain | 
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| silicon | for insulators made of silicon material | 
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| grp | for insulators made of glass fibre reinforced plastic |
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further tags (not new, but proposed to be used)
| Photo | Tagging |
|---|---|
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as well the tag ref can be used to map the number of the catenary mast (i. e. ref=1341-3 in the image) - caution: do not confuse with the tag catenary_mast:disconnector:ref=*!
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| railway:position:exact=*can be used to record the position of the catenary mast | |
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for disuesed catenary masts the tagging with life-cycle-prefixes can be used i. e. for the mast shown in the image |
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the known and documented tagging of location:transition=yes to show that at the catenary mast feeding cables are led from the ground to the top to feed the over head contact line |
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the known and documented tagging of highway=street_lamp can continue to be used unchanged. In urban areas in particular, catenary masts are often used for the installation of street lamps. |
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the known and documented tagging of line_management=* can continue to be used unchanged for cables mounted on top of the catenary mast leading from the substation (or something similar) to the feeding point or feeder lines. It is not proposed to use it to describe the attachment of the over head contact line at the catenary mast because it is not mounted directly at the catenary mast but at the cantilever, head-span, ... |
Examples
Rendering
No changes at OSM carto rendering.
Demarcations
- Tagging is not intended to capture the support of 3rd rail systems (see image on the right), but only overhead contact line masts and their details.
- I thought about tagging the milestone position railway=milestone to the mast as well (as the milestone plates can be attached to the mast on long-distance railways). But I don't think it makes sense to do this, as the information as to whether the milestone plate is attached to the mast is already captured by the tag railway:milestone:catenary_mast=yes at the milestone point.
Features/Pages affected
- Page of power=catenary_mast must be updated.
- Page of Openrailwaymap/Tagging could be completed.
Comments
Please comment on the Proposal_talk:Catenary_mast_details.