Track arrangement of a street railway Grand Union
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.


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.






Czech Republic




Berliner Platz, in Kiel (1971).




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.




United Kingdom



“7/8ths” union
Toronto: King×Dufferin

United States



See also


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


  1. ^ Google. "49°12'16.2"N 16°37'25.5"E" (Map). Google Maps. Google.
  2. ^ Google. "49°35'44.4"N 17°14'50.3"E" (Map). Google Maps. Google.
  3. ^ Google. "50°06'12.7"N 14°28'23.9"E" (Map). Google Maps. Google.
  4. ^ Google. "50°05'55.9"N 14°25'59.8"E" (Map). Google Maps. Google.
  5. ^ "Gleisplan der Straßenbahn Cottbus" (in German).
  6. ^ Google. "49°00'09.0"N 8°23'39.8"E" (Map). Google Maps. Google.
  7. ^ Google. "49°00'37.1"N 8°21'31.8"E" (Map). Google Maps. Google.
  8. ^ "Die Kombilösung Karlsruhe: Für Gründung von Masten wird Rüppurrer Straße zeitweise schmaler" (in German). 16 October 2017.
  9. ^ Google. "49°00'16.3"N 8°24'37.9"E" (Map). Google Maps. Google.
  10. ^ "Planning approval Map" (PDF) (in German).
  11. ^ Google. "51°19'04.9"N 9°30'01.0"E" (Map). Google Maps. Google.
  12. ^ Google (2018-07-05). "51°18′43.0"N 9°29′29.6"E" (Map). Google Maps. Google. Retrieved 2018-07-05.
  13. ^ Google. "48°08'15.3"N 11°35'17.0"E" (Map). Google Maps. Google.
  14. ^ Google. "Piazza Ventiquattro Maggio" (Map). Google Maps. Google.
  15. ^ Google. "Piazzale di Porta Lodovica" (Map). Google Maps. Google.
  16. ^ Google. "45°28'42.2"N 9°11'49.0"E" (Map). Google Maps. Google.
  17. ^,-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. ^,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. ^,4.875219&sspn=0.000423,0.001206&ie=UTF8&ll=52.37002,4.850273&spn=0.000423,0.001206&t=k&z=20&layer=c&cbll=52.370064,4.850241&panoid=MEYZKi8jBNVh2LMqNmB2-w&cbp=12,246.16718307695862,,0,5 Google Maps: Jan Evertsenstraat 144II 1056 Amsterdam, the Netherlands
  20. ^,4.901474&sspn=0.000598,0.001206&g=52%C2%B021%2717.39%22N+4%C2%B054%274.49%22E&ie=UTF8&ll=52.352804,4.89117&spn=0.000423,0.001206&t=k&z=20 Google Maps: Ceintuurbaan 55-157 1072 Amsterdam, the Netherlands
  21. ^,+4.477485&hl=en&sll=51.911483,4.477728&sspn=0.002862,0.008256&t=h&z=16 Google Maps: Vasteland - Westzeedijk Rotterdam, The Netherlands
  22. ^,+16%C2%B054%2748.53%22E&hl=en&ie=UTF8&ll=52.410529,16.913557&spn=0.000439,0.001206&sll=52.407766,16.912468&sspn=0.000439,0.001206&t=k&z=20 Google Maps: Franklina Roosevelta 11, Poznań, Poland
  23. ^,+16%C2%B054%2744.97%22E&hl=en&ie=UTF8&ll=52.407766,16.912468&spn=0.000439,0.001206&sll=52.402659,16.889031&sspn=0.000439,0.001206&t=k&z=20 Google Maps: Rondo Kaponiera, Poznań, Poland
  24. ^ Google. "52°24'09.5"N 16°53'20.7"E" (Map). Google Maps. Google.
  25. ^ Google. "52°23'24.4"N 16°53'39.1"E" (Map). Google Maps. Google.
  26. ^ Google. "52°22'48.7"N 16°56'35.2"E" (Map). Google Maps. Google.
  27. ^ Google. "52°23'57.5"N 16°57'09.0"E" (Map). Google Maps. Google.
  28. ^,20.993619&spn=0.000441,0.001206&sll=52.236994,20.980161&sspn=0.000441,0.001206&t=k&z=20 Google Maps: 629 Warszawa, Poland
  29. ^,20.980161&spn=0.000441,0.001206&sll=52.254707,20.982457&sspn=0.000882,0.002411&t=k&z=20 Google Maps: Rondo Kercelak, Warszawa, Poland
  30. ^,20.982457&spn=0.000882,0.002411&sll=48.137884,11.588259&sspn=0.000961,0.002411&t=k&z=19 Google Maps: Rondo Zgrupowania AK "Radosław", Warszawa, Poland
  31. ^,49.112853&hl=en&ll=55.780444,49.113012&spn=0.00081,0.002411&sll=55.780459,49.112862&sspn=0.00162,0.004823&t=k&z=19 Google Maps: 55.780459 N, 49.112853 E
  32. ^,138.599959&sspn=1.020084,1.683655&ie=UTF8&hq=&hnear=Moscow,+Russia&ll=55.795831,37.714243&spn=0.000683,0.001644&t=k&z=19 Google Maps: Preobrazhenskaya Ploshad, Moscow Russia
  33. ^ "Google Maps".
  34. ^ "Google maps".
  35. ^ "Google maps".
  36. ^ "Google Maps".
  37. ^,9.500285&sspn=0.000433,0.001206&ie=UTF8&ll=47.551401,7.595375&spn=0.000934,0.003433&t=k&z=19 Google Maps: Aeschenplatz 1 4052 Basel, Switzerland
  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". Retrieved 2013-01-07.
  40. ^ "Musée McCord Museum photograph - Tramway crossing under construction, 1893". Retrieved 2013-01-07.
  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. ^ Photo "tower18l.jpg" taken June 19, 2006.(Retrieved November 2009)
  52. ^ "Original PRT specialwork drawing sheet 10, chart 48". 1919-06-30. Retrieved 2013-01-07.
  53. ^ "PTC Track Map detail, 1954, bottom right corner of image". Retrieved 2013-01-07.
  54. ^ "Original PRT specialwork drawing sheet 16, chart 66". 1919-06-30. Retrieved 2013-01-07.
  55. ^ "PTC Track Map detail, 1954, center left of image". Retrieved 2013-01-07.
  56. ^ "PTC Track Map detail, 1954, center left of image". 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". 2005-03-20. Retrieved 2013-01-07.
  59. ^ "Powers Building photograph, Rochester NY, 1904". Retrieved 2013-01-07.
  60. ^ "Waiting-for-8-14-23-THENWEB.JPG (1200x819 pixels)". 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". Retrieved 2013-01-07.
  63. ^ Google. "37°52'21.6"S 145°01'29.0"E" (Map). Google Maps. Google.