Proposal talk:Gantry Expansion

Structural

• gantry:construction=* vs gantry:structure=* : Seems indistinguishable. tower:construction=* has tower:construction=dome and tower:construction=dish which don't fit anyway. power=* uses structure=lattice , structure=solid , and structure=tubular . bridge:structure=* uses bridge:structure=beam instead. man_made=tower is the only one to use *:construction=* , while all others use *:structure=* . I would simply move gantry:structure=* to gantry=* , and move gantry:construction=* to gantry:structure=* to standardize. You could even adopt unprefixed structure=* instead of Template:Gantry:* for less namespacing, especially when they are interchangable.
• gantry:construction=*
  • *=girder vs *=beam : I don't understand what they are distinguishing
• gantry:structure=*
  • *=span : It's called "portal", as in catenary_mast:supporting=portal . I doubt "span gantry" is a term.
  • *=cantilever : Cantilever doesn't mean one-ended or one-winged, only how it's supported. (Theoretically one might make a "portal" gantry from cantilever similar to bridges) Eg T-shaped. https://www.shutterstock.com/image-photo/road-sign-highway-information-go-austria-438728434

Kovposch (talk) 09:11, 21 September 2026 (UTC)

man_made=tower is the only one to use *:construction=* , while all others use *:structure=*

This is sensible to me, I was only familiar with the tower scheme as I rarely map bridges or power structures.

I would simply move gantry:structure=* to gantry=* , and move gantry:construction=* to gantry:structure=* to standardize.

You could even adopt unprefixed structure=* instead of gantry:*=* for less namespacing, especially when they are interchangable.

I will implement these, thanks. For structures: the page seems optimized around power structures. If I use structure=* for gantries, I feel it would be necessary for another table to be defined specifically for gantries.

*=girder vs *=beam : I don't understand what they are distinguishing

From the examples I was studying on commons, there seemed to be several that used I-beams for the structure, and several (in the UK) that were using some structures that were made with panels or even solid or hollow rectangular concrete structures which I wanted to be able to represent but I wasn't able to find any terms for these structures.

https://commons.wikimedia.org/wiki/File:Gantry_in_middle_of_Thelwall_Viaduct_-_geograph.org.uk_-_4441328.jpg

https://commons.wikimedia.org/wiki/File:Gantry_over_A814_near_Broomhill_-_geograph.org.uk_-_6369655.jpg

https://commons.wikimedia.org/wiki/File:Gantry_on_the_River_Avon_crossing_-_geograph.org.uk_-_4427118.jpg

*=span : It's called "portal", as in catenary_mast:supporting=portal . I doubt "span gantry" is a term.

works for me

*=cantilever : Cantilever doesn't mean one-ended or one-winged, only how it's supported. (Theoretically one might make a "portal" gantry from cantilever similar to bridges) Eg T-shaped.

What term would you recommend for a one-ended gantry?

-- SherbetS (talk) 16:44, 22 September 2026 (UTC)

Not very familiar with structures, especially gantries. There are quite many forms. I will need some time to study them. https://www.sabre-roads.org.uk/forum/viewtopic.php?t=41732 Kovposch (talk) 07:57, 25 September 2026 (UTC)

There are terms "half gantry", "semi-portal", and "half butterfly". Although, some sources seem to use "cantilever" to mean the horizontal member is a single arm, not trusses. The T-shaped ones could be clearly called butterfly though. Kovposch (talk) 08:22, 25 September 2026 (UTC)

• *=lattice : On a side note, this seems possible to refer to non-planar spans, or vertical masts/towers only. "Truss" is commonly used, as on bridges.

Kovposch (talk) 08:32, 25 September 2026 (UTC)

Functional

gantry:use:*=*

• *=highway vs *=railway should first be distinguished, to relate features for the same transportation, and not have complicated *:railroad_*=* . *:signals=* is for road only, when there are signals at *:railroad_crossing=* . *:railroad_crossing=* doesn't immediately show it's for the road, which might be for rail signals, although that may not exist.
• It is mixing up device and purpose. This causes *:toll=* to be defined as "cameras and/or sensors" ; *:speed_camera=* as "cameras and/or sensors" ; and *:camera=* as "surveillance cameras for traffic monitoring". There's already enforcement and surveillance for the latter two, which further includes other purposes.
• It's possible to have overlaps, eg traffic_sign=variable_message (or another tag) showing tolls at or near highway=toll_gantry
• There's often this recurring problem of reinventing all keys and vals in other features or attributes, eg why *:signals=* , *:railroad_signals=* , and *:railroad_crossing=* ; and one has to remember or distinguish between different features. Now in indication:*=* , the feature is simply prefixed and reused, eg indication:power=cable , not confused or reinvented as indication=cable or indication=power_cable / / indication=electricity_cable.

Suggestion

• gantry:use=*
  • gantry:use=highway : Includes gantry:use:railroad_crossing=yes
  • gantry:use=railway : Includes gantry:use:railroad_signals=yes
• mounted:*=* (personally would reserve supported:*=* for things on wires indirectly held by poles)
  • gantry:use:destination_sign=* → mounted:traffic_sign=destination
  • gantry:use:variable_message=* → mounted:traffic_sign=variable_message
  • gantry:use:speed_camera=* → mounted:highway=speed_camera
  • gantry:use:camera=* → mounted:man_made=surveillance
  • gantry:use:railroad_signals=* → mounted:railway=signal
• is_for:*=* (open to better naming )
  • gantry:use:toll=* → is_for:highway=toll_gantry
  • gantry:use:railroad_crossing=* → is_for:railway=level_crossing

Kovposch (talk) 09:54, 21 September 2026 (UTC)

*=highway vs *=railway should first be distinguished, to relate features for the same transportation

Works for me. Perhaps a hypothetical preset could be either "highway gantry" or "railroad gantry" and it would apply man_made=gantry and gantry:use=highway or gantry:use=railway then allow for other tags to be chosen?

gantry:use:destination_sign=* → mounted:traffic_sign=destination

gantry:use:camera=* → mounted:man_made=surveillance

Would this be applied on other objects, or on the gantry itself? I intended gantry:use*=* to represent "this gantry is being used for this purpose" so it would be easy to query something like "all gantries that feature a variable message sign" without having to separately query for attached variable message signs.

-- SherbetS (talk) 16:59, 22 September 2026 (UTC)

man_made=gantry + mounted:*=* for what's mounted on it Kovposch (talk) 08:42, 25 September 2026 (UTC)