Grand unions
Full grand union
Three-quarter union
Half union
Butterfly union
Some switches in the first three diagrams are shown combined as three-way switches, even though they would usually be built as two separate switches.

A grand union is a rail track junction where two double-track railway or tramway lines cross at grade, often in a street intersection or crossroads. A total of sixteen railroad switches (sets of points) allow streetcars (or in rarer installations, trains) coming from any direction to take any of the three other directions. The same effect may be achieved with two adjacent wyes if the location allows for space.

## Complexity

These types of complex junction are expensive to build and expensive to maintain. Special parts, sometimes made of manganese steel, are needed for each location where one rail crossed another (a "frog"); these parts often need to be custom-made and fitted for each single location, depending on the specific angle of crossing of the intersecting streets.

A full grand union junction consists of 88 frogs (where one rail crosses another rail), and 32 switchpoints (point blades) if single-point switches are not used. A tram or train crossing the junction will encounter four or twenty frogs within the space of crossing the junction.

For all of the possible tracks of a grand union to be used during normal operation, at least six different tram routes have to cross the union. In an intersection with lines oriented towards cardinal directions, these could be: north-south, north-east, north-west, south-east, south-west, and east–west.

## Three-quarter, half and butterfly unions

Three-quarter unions are similar to grand unions in that they are also rail track junctions where two double-track railway lines cross at grade, often in a street intersection or crossroads; the primary difference being that one corner of the crossing does not have curved junction tracks, with the union having a total of 12 railroad switches (sets of points).

Half unions are similar, but have curved junction tracks on only two adjoining corners of the intersection, with a total of eight switches.

Butterfly unions share the total of eight switches, but the curved junction tracks are on opposing corners.

## Examples

### Europe

#### Austria

• Vienna has a three-quarter union at Quellenplatz, 48°10′32.3″N 16°22′24.7″E

#### Belgium

• Brussels has a grand union at carrefour Buyl - Général Jacques, 50°49′05.9″N 4°22′45.8″E

#### Croatia

• Zagreb has a grand union at the intersection of Savska and Vodnikova Street, 45.80545°N 15.96627°E, and a three-quarter union at the intersection of Vukovarska and Držićeva Avenue, 45.80113°N 15.999°E.

#### Czech Republic

• Brno, has a three-quarter union located at 49°12′16.24″N 16°37′25.54″E.[1]
• Olomouc, has one grand union located at 49°35′44.42″N 17°14′50.27″E.[2]
• Prague, has three grand unions, first at 50°6′12.65″N, 14°28′23.89″E[3] the second at 50°5′55.94″N, 14°25′59.76″E.[4] and the third at 50°4′23.19″N 14°24′50.30″E, this Grand Union was rebuilt in 2003 and has curved trackwork as the streets are not aligned at the river crossing.

#### Estonia

• Tallinn will have the first butterfly union at the intersection of Narva maantee, Hobujaama and A. Laikmaa streets at 59°26′14.07″ N 24°45′26.21″ E. The crossing line is under construction as of 2023 and is expected to start service in 2024.

#### Finland

• Helsinki has a three-quarter union at the intersection of Simonkatu and Mannerheimintie, 60.1699°N 24.9385°E, and a butterfly union at the intersection of Runeberginkatu and Mannerheimintie, 60.1817°N 24.9273°E. These are probably the northernmost unions in the world.

#### Germany

• Cologne has one grand union at the stop Aachener Straße / Gürtel at 50°56′13.2″N 6°54′30.4″E, and one three-quarter union at Barbarossaplatz 50°55′42.9″N 6°56′33.7″E
• Cottbus has one grand union at 51°45′39.86″N 14°19′51.39″E and a three-quarter union at 51°44′57.54″N 14°19′42.50″E.[5]
• Dresden has a grand union at 51°3′49.47″N 13°44′48.95″E (Albertplatz); a five-eighths grand union at 51°3′47.55″N 13°44′13.53″E there is only a single connection on the north route, and a butterfly union at 51°2′58.09″N 13°44′39.27″E (Dresden HBf)
• Duisburg has a butterfly union at 51°30′7.44″N 6°45′25.78″E
• Kiel had a half union on Berliner Platz.
• Erfurt has a butterfly union at 50.976099°N 11.034358°E, its modern city center: the Anger.
• Karlsruhe's system has three grand unions located at Stop Mathystrasse (49°0′8.96″N 8°23′39.77″E),[6] located at Entenfang (49°00′37.1″N 8°21′31.8″E).,[7] and the third one established in 2018 at intersection Rüppurrer Str. and Baumeisterstr.[8][9] A fourth one is planned at the next intersection of Kriegsstr. and Baumeisterstr.[10]
• Kassel's system has a single grand union located at 51°19′4.87″N 9°30′1.02″E and a three-quarter union at 51°18′43.02″N 9°29′29.64″E.[11][12]
• Leipzig has a grand union at 51°20′39.35″N 12°22′15.99″E it is unique in interfacing with four tracks at Goerdelerring tram stop. There is a three-quarter union at 51°19′56.49″N 12°20′19.68″E, a half union at 51°20′31.31″N 12°21′31.15″E and butterfly unions at 51°19′12.95″N 12°19′48.80″E, 51°20′20.36″N 12°21′44.96″E and 51°21′44.93″N 12°21′55.79″.
• Munich has one real grand union at Ostfriedhof since the last track alteration in 2015 at 48°07′8.6″N 11°35′1″E. While not a traditional grand union, the Munich tram system has also a "Grand circle" which has the same route function as a grand union and also provides a loop for all lines, it is located at Maxmonument in Maximilianstrasse, 48°8′15.27″N, 11°35′17.02″E.[13]

#### Italy

• Milan: the Milan tram network currently has two grand unions. The first is a non standard design with divided North South tracks around a monument located at piazza 24 Maggio,[14] and the second located nearby at piazzale Porta Lodovica.[15][note 1] There used to be another large one until the 1990s located at piazza della Repubblica,[16] but it has since reduced to a wye junction still keeping the layout of diverging routes by the removal of the straight route to via Vittor Pisani.

#### Netherlands

• Amsterdam, Netherlands: As of 2009, the Amsterdam tram system continues to have four grand unions. However, none of them has tram routes running in all directions under normal operation. They are located at 52°21′17.39″N 4°54′4.49″E;[17] 52°21′45.91″N 4°52′31.04″E[18] and 52°22′12.13″N 4°51′0.94″E.[19] and 52°21′9.99″N 4°53′28.04″E;[20]
• Rotterdam: the Rotterdam tram system has one three-quarter union, located at Vasteland - Westzeedijk 51°91′14.94″N, 4°47′74.85″E;[21]
• The Hague: The Hague tram system has one butterfly union at the crossing of the Laan van Meerdervoort and the Koningin Emmakade/Waldeck Pyrmontkade (S100), (52°04′54.1″N 4°17′15.9″E). There is also a half union at the crossing of the Loosduinseweg and the Monstersestraat, (52°04′22.2″N 4°17′30.5″E)

#### Poland

• Kraków has three grand unions, one at 50°3′27.42″N 19°57′32.40″E one at 50°3′23.40″N 19°56′43.63″E and one at 50°4′46.65″N 20°1′38.49″E. There is a "Grand Circle" at Centralny Square, 50°4′19.56″N 20°2′14.46″E, the "Grand Circle" which has the same route function as a grand union and also provides a loop for all lines. There is a three-quarter union at 50°3′6.26″N 19°56′30.22″E and a five-eighths union at 50°4′24.31″N 20°1′2.89″E.
• Poznań: The Poznań Tram system has 6 grand unions, which may be the most extant in any city. They are located at: 52°24′37.94″N, 16°54′48.53″E;[22] 52°24′28.02″N, 16°54′44.97″E;[23] 52°24′9.54″N, 16°53′20.65″E;[24] 52°23′24.39″N, 16°53′39.07″E;[25] 52°22′48.68″N, 16°56′35.21″E[26] and 52°23′57.53″N, 16°57′8.97″E.[27] All can be seen in detail on Google Earth.
• Warsaw: The Warsaw system has four grand unions, first at 52°14′30.79″N 20°59′37.00″E[28] second at 52°14′13.30″N 20°58′48.62″E,[29] third at 52°22'01.84"N, 21°00'49.14"E, and fourth at 52°18'87.92"N 21°00'20.16"E.

There is a three-quarter union at 52°15′17.24″N 20°58′57.11″E,[30] and 52°26'35.68"N 21°02'07.88"E.

#### Russia

• Kazan: Kazan Tram system had one grand union. It is located at 55.780459 N, 49.112853 E. Street View in Google Earth shows that this Grand Union has been partially removed, portions still remain in the pavement in 2013.[31]
• Moscow: Moscow Tram system has one three-quarter union on Preobrazhenskaya Ploshad[32]
• Saint Petersburg: Saint Petersburg Tram system has a three-quarter union on Svetlanovskaya Ploshad,[33] a three-quarter union on Irinovskiy Prospekt[34] and a butterfly union on Prospekt Kultury[35]
• Angarsk: Angarsk Tram system had one Full grand union which was partially dismounted in 2000-s[36]

#### Slovakia

• Košice, had one grand union at 48°42′18″N 21°14′35″E, in 2018 that was replaced with a Grand Circle, which can be seen on Google Earth.

#### Switzerland

• Basel, the Basel system has a grand union at 47 33' 48.62"N 7 35' 57.96"E and a (nonstandard) grand union located at 47°33′4.83″N 7°35′41.89″E.[37]

### Americas

“7/8ths” union
Toronto: King×Dufferin
• Toronto: The most extensive street railway system in the Americas is the Toronto streetcar system of the Toronto Transit Commission in southern Ontario, which has many four-way streetcar intersections, including the only extant grand unions remaining in the Western Hemisphere. The system includes three grand unions, one seven-eighths union (one curve short of a grand union), four three-quarter unions (missing 2 curves at a single corner), three more unions with 6 curves and many unions in various configurations with less than 6 curves. The "traditional" grand unions are located at Bathurst and King (43°38′38.14″N 79°24′9.50″W); Spadina and King (43°38′43.73″N 79°23′42.09″W) and Spadina and Queen (43°38′55.43″N 79°23′46.91″W).[41] King and Dufferin (43°38′20.15″N 79°25′38.45″W) is a "seven-eighths union": it is missing the curve from southbound to westbound.[42]
• Brantford, Ontario The Brantford Municipal Railway installed a UK-made grand union at Colborne and Market Streets circa 1910. It remained in service until the end of streetcar service in the city on 31 January 1940.[43] It was taken up for scrap in 1940.[44]

#### United States

• Akron: The Akron streetcar system had one grand union at the intersection of Main and Exchange Streets,[45]
• Boston: The Boston Elevated Railway had four grand unions on Washington Street, at Hanover Street,[46] Boylston and Essex Streets,[47] Southampton Street, and Dover Street.[48] Dover Street was also a part of another, albeit asymmetrical, grand union where it intersected Tremont Street and terminated into Berkeley Street, leading to another grand union at the intersection of Berkeley and Columbus Avenue. Another grand union existed at the intersection of Massachusetts Avenue and Huntington Avenue.[49] An eighth grand union had existed at Dewey Square.[50]
• Chicago: The Chicago Transit Authority has a three-quarter union at Tower 18, located on the northwest corner of The Loop. This union has the notable distinctions of not only being built entirely on elevated bridgework over the streets below, but also being fully equipped with third rails for power distribution.[51]
• Philadelphia: SEPTA has a surviving example of a half union located at the intersection of Chester Avenue and 49th Street;[52][53] and PTC previously had two butterfly unions, the first at Erie Ave and Old York Road[54] and the second at Lancaster Avenue and 33rd Street;[55] as well as a second half union at Allegheny and 22nd Street.[56]
• Pittsburgh: Pittsburgh's trolley system had a three-quarter union located at the intersection of 5th Avenue and Craig St.[57]
• Rochester, New York: Rochester's surface streetcar system had three full grand unions, all of which were located on Main Street, as well as two three-quarter unions, and three half unions.[58][59]
• Seattle: The Seattle-Tacoma Interurban was believed to have a single grand union, located at N. 34th St. and Fremont Ave.[60]
• San Francisco: The San Francisco Municipal Railway's light rail line has a quarter union at 4th Street and King Street. The N Judah route crosses 4th, and the current T Third route uses the turn connecting the tracks on King northwest of the intersection to those on 4th to the southwest; the tracks on 4th across King lead to the Central Subway, which is planned to carry the T Third when it opens.
• Salt Lake City: The Utah Transit Authority's TRAX system has 2 half unions(Main Street Interlocking at 40°45′38.2″N 111°53′28.3″W and the Airport Junction Interlocking at 40°46′09.7″N 111°54′08.4″W), 1 quarter union (Union Interlocking at 40°43′21.1″N 111°53′48.8″W), and a three interlocking combination that offers the effect of a half union (Lovendahl/Ephraim/Sugar Interlockings at 40°37′56.2″N 111°53′54.7″W).

## Notes

1. ^ In summer 2022 it is going to lose one of the diverging tracks. Works ongoing.

## References

5. ^ "Gleisplan der Straßenbahn Cottbus" (in German).
8. ^ "Die Kombilösung Karlsruhe: Für Gründung von Masten wird Rüppurrer Straße zeitweise schmaler" (in German). 16 October 2017.
10. ^ "Planning approval Map" (PDF) (in German).
17. ^ https://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=52%C2%B021%2717.39%22N+4%C2%B054%274.49%22E&aq=&sll=37.926868,-95.712891&sspn=33.816707,79.013672&ie=UTF8&ll=52.354844,4.901218&spn=0.000423,0.001717&t=k&z=20 Google Maps: Van Woustraat 83III 1074 Amsterdam, the Netherlands
18. ^ https://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=52%C2%B021%2745.91%22N++4%C2%B052%2731.04%22E&aq=&sll=52.352854,4.89117&sspn=0.000423,0.001206&ie=UTF8&ll=52.362792,4.875219&spn=0.000423,0.001206&t=k&z=20 Google Maps: Eerste Constantijn Huygensstraat 98 1054 Amsterdam, the Netherlands
19. ^
20. ^
23. ^
28. ^
29. ^
31. ^
33. ^
34. ^
35. ^
36. ^
37. ^
38. ^ Edmonton Radial Railway 1924 track map Archived July 6, 2011, at the Wayback Machine
39. ^ "Edmonton Radial Railway Society photograph, 109th St. and Jasper Ave., 1904". Edmonton-radial-railway.ab.ca. Retrieved 2013-01-07.
40. ^ "Musée McCord Museum photograph - Tramway crossing under construction, 1893". Mccord-museum.qc.ca. Retrieved 2013-01-07.
41. ^
42. ^ "Toronto streetcar system March 2011". Transit Toronto.
43. ^ "Traction on the Grand", John Mills, Railfare Publishing, 1977.
44. ^ Page 74, Canadian Rail Passenger Review Number 3, 2000, author Douglas NW Smith
45. ^ "Downtown digging uncovers remnants of Akron's streetcar era". Akron Beacon Journal. 2019-04-07. Retrieved 2019-04-08.
46. ^ "Boston 1899-1915 Plate 033". WardMaps LLC. Retrieved 2016-12-25.
47. ^ "Boston 1899-1915 Plate 029". WardMaps LLC. Retrieved 2016-12-25.
48. ^ "Boston 1899-1915 Plate 026". WardMaps LLC. Retrieved 2016-12-25.
49. ^ "Boston 1899-1915 Plate 025". WardMaps LLC. Retrieved 2016-12-25.
50. ^ "Boston 1899-1915 Plate 032". WardMaps LLC. Retrieved 2016-12-25.
51. ^ www.Chicago-L.org Photo "tower18l.jpg" taken June 19, 2006.(Retrieved November 2009)
52. ^ "Original PRT specialwork drawing sheet 10, chart 48". Phillytrolley.org. 1919-06-30. Retrieved 2013-01-07.
53. ^ "PTC Track Map detail, 1954, bottom right corner of image". Phillytrolley.org. Retrieved 2013-01-07.
54. ^ "Original PRT specialwork drawing sheet 16, chart 66". Phillytrolley.org. 1919-06-30. Retrieved 2013-01-07.
55. ^ "PTC Track Map detail, 1954, center left of image". Phillytrolley.org. Retrieved 2013-01-07.
56. ^ "PTC Track Map detail, 1954, center left of image". Phillytrolley.org. Retrieved 2013-01-07.
57. ^ "Partial photo of location". BCoolidge Pittsburgh Trolleys. 2005-11-24. Retrieved 2016-10-25.
58. ^ "Map of Rochester Subway, see inset section for surface track layout". Rocwiki.org. 2005-03-20. Retrieved 2013-01-07.
59. ^ "Powers Building photograph, Rochester NY, 1904". Shorpy.com. Retrieved 2013-01-07.
60. ^ "Waiting-for-8-14-23-THENWEB.JPG (1200x819 pixels)". pauldorpat.com. Archived from the original on 31 January 2013. Retrieved 2 February 2022.
61. ^ Graham Stewart, The End of the Penny Section: When Trams Ruled the Streets of New Zealand, rev ed. (Wellington: Grantham House, 1993), p. 149.
62. ^ "Victorian Heritage Database: photographs and diagram of junction". Vhd.heritage.vic.gov.au. Retrieved 2013-01-07.