Talk:List of longest tunnels

List of tunnel by depth
How about a table listening tunnels by their maximum rock coverage?

Like this: http://www.japan-tunnel.org/nttj/statistical_data/index2.html

Coccodrillo 18:59, 24 October 2007 (UTC)

Metro tunnels
Metro tunnels should be excluded from the main table, in my opinion. They could stay in the separate table, if you like. Metro tunnel as I said are always near the surface and made by several shorter tunnels. There are hundreds of subways, it's useless to add the lenght of all their tunnels. Maybe some particular tunnels could be added (the BART tunnel under the Bay in San Francisco, as example). Coccodrillo 08:18, 1 December 2006 (UTC)

Future of this article?
Any ideas on what should be done with this article, compared with List of tunnels?--ZorroIII 09:04, 2 October 2005 (UTC)
 * Wikipedia is not the Guinness Book of Records. Perhaps a section on the engineering difficulties of building a long tunnel might be useful...
 * No, it isn't, but a plain list list of thousand of uninteresting tunnel would be useless. Coccodrillo 14:27, 5 November 2006 (UTC)
 * Yes, it is -- a list of thousands of interesting tunnels would be quite useful. Ah, the nature of the Wiki-free-for-all...

No CERN?
Surely LEP's 27 km tunnel warrants inclusion.

Other types of tunnels
The CERN tunnel is one example. Another is the networks of tunnels in places where they were used for warfare or as escape routes. Would those be included in such a listing??

I think the middle table, named "Vehicular" should be skipped. The bottom table ("Top 100") covers those tunnels anyway. Tables of other kinds of tunnels could be a good addition.--Blue Elf 20:26, 8 December 2005 (UTC)


 * If someone wants to include other types of tunnels (industrial/mine/others not for public) then try to find some info and go ahead. Minimum requirement: walkable. Some war escape/hiding tunnels are so narrow that they are crawlable, not walkable. I have added some metro railway tunnels, noone else has. - BIL 14:34, 6 November 2006 (UTC)

Norðoyatunnilin (Faroe Islands)
According to my sources (Stamps.fo and the Danish travel guide Turen går til Færøerne of 2005), the tunnel is on 6,300 m and thus some places more in top of the ranking. Where is the 6,100 m in the article from? -- Arne List 19:54, 3 May 2006 (UTC)

Railway tunnels (excluding subways)
Why are subways excluded from this? It seems entirely arbitrary, and excludes some very long tunnels. At the very least, it needs it's own category. Until relatively recently, the Morden to East Finchley section of the London Underground's Northern Line was the world's longest tunnel.
 * It is hard to define what a tunnel is: some underground tunnels are very long, but just under the surface. It is harder (normally) to build 20 km of tunnel under 2000 m of mountains than 100 km of subway tunnel, under 50 m of rocks (build it without causing damages to the buildings on the surface, that is another matter). I think subway tunnels should not be included (often, there are more short tunnels linked one to another). Coccodrillo 17:36, 15 November 2006 (UTC)
 * Be honest, you just want to exclude cut-and-cover. And that's fine. As for the mountains-only idea, the Marmaray underwater tunnel is most interesting and is of decent length. 24.200.248.28 05:25, 17 January 2007 (UTC)
 * Marmaray in my opinion can be included, because is not a subway... Coccodrillo 18:26, 10 February 2007 (UTC)

Also, I think we should exclude tunnels that have not been opened, are or have just been proposed. FrFintonStack 18:30, 25 May 2006 (UTC)
 * While I agree that many proposed tunnels will not be built und thus cause a bloated listing, I think that tunnels well under construction should be mentioned. Maybe not in the main table but then in an additional list.--Klaus with K 09:37, 2 June 2006 (UTC)


 * I added two long Subway/Metro/Underground/Rapid tranist (whichever it is called) tunnels as you suggested. It is hard to find info about such tunnels. /BIL 23:35, 3 June 2006 (UTC)
 * I can add the fact that they were completely removed from the German version of this article, since the stations could not be called tunnels, in their eyes. The Subway tunnels have more passengers than any other tunnel, but still there is hard to find info about them. I have measured some with detailed maps and Google Earth. -- BIL 22:32, 17 January 2007 (UTC)
 * Subways are usually made of several sub-surface tunnels, sometimes built underground, sometimes by cut&cover. I think that these tunnels should not added to this article at all, simply because...there are hundreds of subway lines in the world, each dozens km long, with several other service tunnels. I think a table with the length of hundreds of subways lines is of no interest. Maybe a page about building tunnels in an urban environment, with some exemples, could be more interesting. Coccodrillo 18:26, 10 February 2007 (UTC)

Above, a number of reasons have been given why not to have them in a list, no one good. They are too shallow, they are too long and too many, etc. There are many railway tunnels also but few so long. I can agree one thing, there is very hard to find info about the tunnel lengths. I have used maps and satellite images for some of them, but that could count as original research, that Wikipedia should not be the only place that has published some infomation. -- BIL 22:27, 24 May 2007 (UTC)

Brenner
This tunnel has two (already existing) approaches on the north; measured by the longer Innsbruck bypass approach it will be 62,700 m, thus passing Gotthard. [BBT technical data (in German)] Gotthard, for its part, has an extension under consideration (the Axentunnel, which would increse its overall length to some 75,000 m. As this is only under consideration, it is too early to include in the table. Aldenrw (talk) 19:06, 6 October 2010 (UTC)

New organisation idea
Here is a proposal on how to structure the tunnel lists.


 * List of tunnels would be a central navigational page, leading to:
 * List of tunnels by length, purely based on length, not type
 * List of tunnels by type, with sections for rail and road etc (much like this current page)
 * List of tunnels by location, sorted into countries

We would have a navigation template at the top of each article, linking to the others.
 * Disadvantage of List of tunnels being rather empty, and a new tunnel needs to be mentioned on three pages. But I think these are minor objections.--Klaus with K 09:37, 2 June 2006 (UTC)
 * P.S. The German longest-tunnel-page de:Liste der längsten Tunnel der Erde looks well-structured to me.--Klaus with K 09:50, 2 June 2006 (UTC)

Another idea: the distances should be km (mi). This convention is generally followed (eg the road tunnels on this page don't even list the imperial measurement), but not everywhere on this lists. It makes sense because most of the tunnels use km, ie they are built in countries using metres.--Commander Keane 13:58, 1 June 2006 (UTC)
 * Distances should be metric, I slightly prefer metres over kilometres. As for the imperial measurement, the really real proper way is to use miles and chains.--Klaus with K 09:37, 2 June 2006 (UTC)
 * Distances should be metric first. If no one objects, I will switch soon.--Jusjih 05:51, 22 June 2006 (UTC)
 * No objection, only suggenstions... Length in metres (miles) ... merge the tables and add a small width column (Rail, Road, Metro, Water, Canal...) ... what do you think about comments like on the German page? If you think they make sense I could be convinced to write/translate them.--Klaus with K 16:50, 22 June 2006 (UTC)
 * I cannot read German, so if you wish, please translate.--Jusjih 01:59, 23 June 2006 (UTC)
 * These comments read like 'longest rail tunnel' 'longest road tunnel' 'longest underwater distance' 'longest land-based tunnel' and so on. If you add a comment column, I could add some contents when I find time (it is not that much).--Klaus with K 14:49, 23 June 2006 (UTC)

Avoid water tunnels ?
We should avoid water pipes and tunnels, otherwise we could consider including gas and oil pipelines, often buried, thousands of km. A requirement could be that it shall be used to transport people. /BIL 18:45, 25 June 2006 (UTC)


 * Should we keep a list of "Longest continuous rock tunnel" ? The article about the Bolmen Water Tunnel (82 km) just barely was allowed to exist. There was a vote about whether to delete it. That hints that this type of tunnel is not so interesting. OK, the two listed here are long and more than 2 m in diameter, but still ? BIL 18:14, 22 August 2006 (UTC)


 * Some tunnels built for boats exists: they shuld be included in a separate table! http://home.no.net/lotsberg/ Coccodrillo 17:31, 15 November 2006 (UTC)


 * Why should we avoid water tunnels? That makes no sense. Gas and oil pipes can not be used as an excuse, since they are not tunnels and thus would not be included in the list anyway. I can not see any reason why the requirement should be transporting people. But if such a limitation is set, then that should be mentioned in the article, and the name of the article should be changed to something like "List of road and railway tunnels by length". Current situation is very misleading.
 * The table "The world's longest tunnels - in use" claims that the longest tunnel is Seikan Tunnel (53 km). However, Päijänne Water Tunnel is 120 km. And it is not a "pipe", it is a rock tunnel big enough for a truck. --PauliKL (talk) 15:00, 12 May 2008 (UTC)


 * They are included in List of further tunnels by length article, i think that is enough. --Jklamo (talk) 17:08, 12 May 2008 (UTC)


 * Road and railway tunnels are listed on that page, too. That should be enouch for them, too, and they should be removed from this page (leaving nothing in the list). The name of this page is List of tunnesl by length. It makes no sense to omit the longest tunnels from the list. Therefore, the water tunnels should be added back to this list. Or, at the very least, the name of this page should be changed to something like List of road and rail tunnels by length. But I don't see any purpose for such list, after all the tunnels are listed in the page List of further tunnels by length. Thus, I would say that either the contents of this page should be changed back to include all the longest tunnels, or this page should be removed. --PauliKL (talk) 14:21, 17 August 2008 (UTC)

2009
How come that we right now can have one (but only the longest) water supply tunnel, when we can't have metro tunnels. --BIL (talk) 16:12, 12 November 2008 (UTC)
 * We (collectively and consensually, as editors) can probably agree to put anything we want as the title/introduction, and to fill in the data to reflect that it says on the tin. IIRC, the article did previously state: "Often [metro tunnels] are not considered continuous because the stations do not count as tunnels" ( but that was removed... ).  This sentence least provided an explanation as to why (arbitrarily) metro tunnels had been excluded.  Depending on your point of view, it would probably be sensible to either add the longer metro lines (if the information can be sourced), or to restore the note covering their transfer to a separate listing.  —Sladen (talk) 12:44, 26 February 2009 (UTC)

I would say that many water aqueduct tunnels are most definitely tunnels and not just pipes: constructed using tunnelling techniques like hard-rock drilling and blasting, sited tens or even hundreds of feet below the surface. A problem might be distinguishing which sections of a particular aqueduct are a continuous tunnel (q.v. the Catskill_Aqueduct article, which gives distances of various types of tunnelling but doesn't state whether those are continuous sections or aggregate totals). I do think that water tunnels are more qualified for listing than metro/subway tunnels as metros are frequently constructed as many separate segments of tunnel. Perhaps for the purpose of metro tunnels, segments that are clearly bored as one tunnel section, even if stations are present, could be measured. An example of this would be the Stockholm Metro Blue Line, which is a bored rock tunnel with the stations constructed using mining techniques rather than excavation from surface access. (talk) 21:16, 29 September 2009 (UTC)

Suggestion for the merged tables
I tentatively shortened the Length in metres (miles) and the Year Completed in an attempt to have less empty space in the table. For now I do not have line breaks inside the table cells.--Klaus with K 13:58, 3 July 2006 (UTC)

Merged tables started
I have started to merge the tables, so far railway and road included. Metre values mostly taken from http://home.no.net/lotsberg/data/rail.html and http://home.no.net/lotsberg/data/tun10.html as the old metric values were rounded, some even having suffered metric->imperial->metric conversion. Some metre values look to me like still rounded to the nearest 10m or 100m. Table cutoff a function of my available time today, see notes inside the tables.--Klaus with K 20:29, 7 July 2006 (UTC)


 * I see the necessity to keep the column entries short, the table tends to get quite wide (and the year ranges for the tube tunnels do not help either but I do no know how to avoid it in these cases of staged construction). Short: no multiple mentioning as in Railway/Railroad or Metro/Subway/Tube/Underground, even the single Railroad is slightly on the long side. Distinctive: avoid similarities like Road vs Railroad, Railway vs Subway.--Klaus with K 21:35, 10 July 2006 (UTC)

No Rank numbers please
As new tunnels are being built and completed, each single new entry added to a table would require the change of all subsequent rank numbers which is a maintenance pain. Hence no ordinal numbers please.--Klaus with K 10:46, 1 August 2006 (UTC)


 * According to Road tunnels under construction there are 8 road tunnels to open in the next 4 years. Who is going to edit all these rank numbers in Vehicular each time?--Klaus with K 11:07, 10 August 2006 (UTC)


 * And I planned to merge some of the double-tube tunnels into one, some are considered different tunnels. I planned to rank only top ten, now I have to remove the numbers. /BIL 12:22, 10 August 2006 (UTC)

Merged vehicular tunnel table
We should merge the two tables for Road tunnels. The question is which format ? I waited for a principle regarding the format of other tables, but there is no real agreement between them. I assume I will use the format of the merged table, without the "type" column. In princle as the "Vehicular" but metres and a comment column. /BIL 11:13, 1 August 2006 (UTC)


 * Why only merge the two Road table and not include them in the merged tables at the top? Is it because at any given length there are far more rail than road tunnels?
 * Ok, now to your question. Yes, format of merged table, without type and rank, would do fine. If possible use accurate numbers for the metre values, see sources above. Any opinion whether to preserve the opening days when given?--Klaus with K 16:01, 1 August 2006 (UTC)

Hi BIL, I see you start editing. Remarks from my side: So far my constructive criticism for tonight.--Klaus with K 18:52, 2 August 2006 (UTC)
 * Do away with the rank. Each new tunnel means editing loads of rank numbers.
 * Add miles as well. As a metric person I do not care, but there is imperial folk.
 * Adding info on second tube is good, however, one cannot see whether the old or the new tube is longer. Maybe specify older or younger in place of second. As you use &lt;br&gt;between year, the table entry already is two lines high, so you could do the same for the two lengths, and comment two tubes without the length.


 * Why list numerous vehicular examples by nation, then throw in one listed by an American state? That's apples and oranges. Why not use the same denominator?

Seikan
The Seikan Tunnel hosts two cape gauge (1067 mm) tracks, so it is useless to write "longest metre-gauge tunnel" about the Vereina.

I'm trying to write dedicated pages for some tunnel, such as the Vereina Tunnel. Someone should correct my English. Coccodrillo 13:38, 29 November 2006 (UTC)


 * The Simplon Tunnel should be considered as only one thing. It's true that they were opened 15 years apart, but it's common to open the second tube of any tunnel only when the traffic requires it. Coccodrillo 17:43, 29 November 2006 (UTC)

List of further tunnels by length
Tagged since over a year, I have a bold moment and shall tidy up this page. Noting that people have invested work into the non-merged sections, I'll move this content to a page to be named List of further tunnels by length and leave it to others if they feel this leftover sections should be reorganised differently.--Klaus with K 16:43, 24 May 2007 (UTC)

Metres --> Kilometres?
I don't think this needs to be in metres. There is no need for 5 figure accuracy here. An extra decimal can be added in order to seperate an tunnels that are close in length. Agree/Dissagree?Shniken1 02:18, 27 September 2007 (UTC)

Disagree Technical information is given in metres, the plans are of better accuracy than mere metres, and I do not see a reason why one should downgrade information. Adding decimals later means sourcing information again, giving different numbers of decimals makes for an incoherent appearance of the table. -- Klaus with K 09:49, 27 September 2007 (UTC)

Disagree per Klaus with K, anyway for correct length sorting we need at least 4 figure accuracy --Jklamo 16:42, 27 September 2007 (UTC)

Mont d'Ambin Base Tunnel
This tunnel is at planning stage. Some intermediate access on the french side have ben built, but nothing on the italian side and it is not sure that the main tunnel will be built. There have been seveal announces, but nothing has been done untill today. Coccodrillo (talk) 22:19, 5 February 2008 (UTC)

What counts
This edit (Removing water ans [sic] electricity tunnels. If someone does not like this, please explain on the discussion page where it is defined that they should be include). I don't have an objection, but it would be useful to have a definition for what this list is; currently going by the tunnel it is merely tunnels - in use. The two tunnels: Should we rename this to "transport tunnels"? There are other interesting examples; Eg. —Sladen (talk) 20:44, 9 February 2009 (UTC)
 * Päijänne Water Tunnel (Finland, 120 kilometres, 1 × 16 m2) is a bare rock tunnel is sufficiently large enough to drive the service vehicles along.
 * The London Connection (London, 20 kilometres, 1 × 7 m2) is a TBM-bored tunnel with its own suspended monorail system.
 * Channel Tunnel Rail Link combined East/West Tunnels (London, 7+10 kilometres, 2 × 40 m2) but separated in the middle by the sunken Stratford International railway station (1 kilometre) "box".


 * I think that in the list only traffic (railway and road) tunnels must be shown, except S-Bahn and metro tunnels in cities.
 * A lot of electric tunnels have service raiwlays along them, but these railways are only used to mantain their tunnel (eg transporting cables, tubes, etc), not to transport goods. So i think they shoult not considered here. Maybe they cab be included in a separate table, but not on the main table.
 * Two bored tunnels, built separately, but linked by an artificial part can be considered a single tunnel. But the Stratford station seems to be opened, even if in a trench, so the two 10 and 7 km tunnels can't be counted as one.
 * Coccodrillo (talk) 14:07, 14 February 2009 (UTC)

I would like to add a tunnel to this list! Called the Orange River Fish Tunnel located in South Africa. Second longest water tunnel in the world at 82.5Km (51Miles) and 5.35m (17.5ft) in diameter —Preceding unsigned comment added by Ajax0121 (talk • contribs) 00:43, 26 February 2009 (UTC)
 * ✅ —Sladen (talk) 12:47, 26 February 2009 (UTC)


 * There are hundreds of water tunnels longer than 13 km, if we add all of them the list would bee endless...
 * I think also that the numbers in List of long tunnels by type should be more precise (ie 28,377 m instead of 28.4 km for the Guadarrama tunnel) Coccodrillo (talk) 11:06, 3 March 2009 (UTC)
 * If we had more information, we would easily be able to restrict it to say, the top 1% for each type. At the moment the only criteria for the list is "tunnels - in use";  so if you can find them add them.  —Sladen (talk) 11:32, 3 March 2009 (UTC)
 * Some water tunnels longer than 13 km in Switzerland: Altstaffel-Robiei 13 km, Bärenburg-Sils 13 km, Grande Dixence 13 km, Lucomagno-Luzzone 14 km, Olivone-Malvaglia 15 km, Riddes 15 km, Caverna-Palgnedra 23 km. Coccodrillo (talk) 18:28, 6 March 2009 (UTC)

Sorting by Length is broken
As it's performing an alphabetic sort instead of numeric. I've read Help:Sorting and thought hidden keys must be the way to go but can't get it to work. Any wiki gurus in the house able to shed light on how to fix this up? Oosh (talk) 06:18, 4 January 2010 (UTC)

Brenner
The Brenner Base Tunnel will connect underground with the existing Innsbruck bypass Tunnel, for a total length of 62.7 km. Thus, the total length will exceed that of the Gotthard Base Tunnel by over 5km. Seems obvious to me. Comments?

Brenner Base Tunnel project page

Aldenrw (talk) 21:31, 19 February 2010 (UTC)


 * I think that if it is chosen 62.7 as length then the name in the table should be changed in "Brenner Base+Innsbruck Bypass" or similar with a note explaining that there are two linked tunnels, with a different history and structure (two single track tubes the Brenner, one double track tube the bypass). Another similar case will touch the Gotthard Base Tunnel if and when the proposed Axen tunnel is connected directly with it. The GBT has yet two underground caverns for that. Coccodrillo (talk) 20:24, 27 February 2010 (UTC)

The refs, the refs
WP calls for the use of templates such as cite web, cite book, etc. These raw web sites are practically useless. Also, this IS the English WP. I realize we are writing about an international topic, but in English. Sometimes there is no other recourse than to use sites in the original language. These are, as I say, useless to most English speakers. This is one of the drawbacks to being a speaker of a dominant language. Most Europeans speak at least another, but you don't realize English is in most cases our only language. I've heard the academics rail about this ignorance all my life and yet it is just as true today as it was in 1980 (sure, Dave. 1950?). To us, Reykjavik is still rinkey-dink. I recast the first ref to show you what might be done with Internet resources. If you could manage something like it for the rest of the gobbledeygook I am sure most native English speakers would appreciate that greatly, as this is quite an interesting article. As for the non-Roman alphabets - forget it, I am sorry to say. Try to get something in English.Dave (talk) 10:48, 27 February 2010 (UTC)

Gotthard Base Tunnel incorrectly added to the longest tunnels in use
The final break through in the east tube occurred on 15 October 2010. The break through in the west tube isn't expected until April 2011.

People keep adding this tunnel to the list of tunnels in use. It may not be completed until 2017 so is not in use.

StuZealand (talk) 21:22, 15 October 2010 (UTC)

Kárahnjúkar
The Kárahnjúkar hydroelectric plant in Iceland involves a tunnel network with 72 kilometers of tunnels combined, however the longest distance from one opening to another is 39.7 kilometers. Here is a description, here is an overview of all the tunnels and here is a map where the tunnels are marked with blue lines. Which number should be used in the list? --85.220.101.221 (talk) 18:12, 16 October 2010 (UTC)

Gotthard Base Tunnel
Adept for new record --W.Rebel (talk) 22:42, 16 November 2010 (UTC)

something is amiss
When the top table, World's longest tunnels (in use), first loads with the page it is ordered by length from longest to shortest. Well and fine. If you click to reverse the length order, it appears to be fine. But if you click again to return to longest>shortest the top 2 entries (Delaware Aquaduct and Päijänne Water Tunnel) disappear. Refreshing the page returns to proper state.  ◦◦derekbd  ◦   ◦my talk◦◦  03:43, 9 July 2011 (UTC)


 * Noticed this as well. The 'UNK proton accelerator' of ~21,000 m, also behaved incorrectly because of a misplaced ~. This I corrected but what the other two problems could be, I am at a loss. The code for these looks perfectly fine.. AlwaysUnite (talk) 20:45, 7 August 2013 (UTC)

Qanats
I'm unsure as to the requirements for inclusion but should this list possible include (still functioning) qanats? The Wardak Qanat with 8m seems to qualify, as does the Turpan water system which seems to include qanats up to 10km long (the German wiki has a source for that). The Gadara qanat was an impressive 94km but probably doesn't qualify as it's no longer operational. Akerbeltz (talk) 23:01, 13 August 2013 (UTC)
 * The list now seems to be limited to tunnels longer than 14 km. So that leaves only the Gadara qanat: I've tentatively created a new section for it: 'abandoned tunnels.' Let's see what happens. Uanfala (talk) 00:10, 28 September 2015 (UTC)

Thirlmere Aqueduct
Thirlmere Aqueduct is not continuous (see File:Thirlmere Aqueduct Higher Wheelton.jpg or ) and it is more likely pipeline than tunnel. I think it should be excluded from this list. --Jklamo (talk) 17:48, 17 November 2013 (UTC)

This point is so obvious that I am astounded that Thirlmere was ever included in this article.Flying Stag (talk) 23:18, 29 November 2013 (UTC)

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Seikan Tunnel still longest railway tunnel?
Is the Seikan Tunnel still the "Longest railway tunnel excluding urban metro lines with intermediate stations" now that the Gotthard Base Tunnel has been completed? — Preceding unsigned comment added by Scotteaton92 (talk • contribs) 14:53, 1 June 2016 (UTC)

Lengths are probably kilometers, not meters
Of all tunnels the lengths are expressed as a number with 1...3 digits before the decimal. Probably kilometers are stated. 29,900 m (18.6 mi) should obviously be 29,900 km (18.6 mi). One mile is 1609m not 1.609m. It is probably a bug in the convert script : \{\{convert|57091|m|mi|1|abbr=on}} which introduces a decimal point in the meter value. It should evaluate 57091m and not 57.091m. S k a t e b i k e r (talk) 18:35, 1 June 2016 (UTC)
 * In conventional English notation, "29,900 m" is twenty-nine thousand nine hundred metres, not twenty-nine point nine metres. So "29,900 m (18.6 mi)" is correct. I see from your home page that you're from Holland where (I'm guessing) "29,900 m" would be read as twenty-nine point nine metres. -- Hux (talk) 20:35, 12 October 2021 (UTC)

The convert template uses the convention of a decimal point "." and a comma "," for decimal grouping. see Decimal_mark. Scotteaton92 (talk) 20:16, 1 June 2016 (UTC)

"Second longest..."
An IP added this to the Channel Tunnel: "Second longest railway tunnel until Gotthard tunnel was opened." This is true, but not really notable. We do not list "second anything" in general, unless there is a particular reason. The IP's edit comment claimed to be reverting me -- so I assumed I had made a mistake -- but in fact the version I removed was a claim to be the longest. Just for the record. Imaginatorium (talk) 07:18, 8 June 2016 (UTC)


 * No harm in listing "second" especially since it was also the longest in the Western world, not just in England. This is also been the 2nd longest for about 20 years. — Preceding unsigned comment added by 101.178.163.8 (talk) 01:53, 9 June 2016 (UTC)

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Is this a contradiction?
Guangzhou Metro Line 3, at 57930 m, is listed as the "longest metro/rapid transit tunnel". Immediately below that, the Gotthard Base Tunnel, at 57104 m, is described as "...also the world's longest transit tunnel." Those statements can't both be true, can they? Or am I missing something? -- Hux (talk) 20:31, 12 October 2021 (UTC)


 * Just coincidentally cleared up the confusion of this before seeing your post! It's longest by geodetic distance which I've made more clear FlyingScotsman72 (talk) 06:05, 6 July 2023 (UTC)

How is "advanced planning stage" being defined?
It isn't clear to me what this is supposed to mean. For instance, the Taiwan Strait Tunnel Project is currently a member of this list, but the article states "The project is not considered viable due to a lack of interest from the Taiwanese, staggering costs and unsolved technical problems". I would have interpreted "advanced planning stage" as a project that is, at the very least, expected to obtain approval in the foreseeable future. Scleractinian (talk) 05:55, 12 August 2022 (UTC)
 * Feel free to clean-up that section. In fact, several of the tunnels on the list are not actually at an advanced planning stage.--Jklamo (talk) 09:15, 12 August 2022 (UTC)