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{{Short description|Rail loop for turning vehicles}}
{{Short description|Rail loop for turning vehicles}}
{{Multiple issues|
{{More citations needed|date = April 2018}}
{{One source|date = April 2018}}
{{Pros and cons|date = September 2024}}
}}
[[Image:Vandslinga Sparvag.jpg|right|thumbnail|Balloon loop at Linnéplatsen at the [[tram]]way in [[Gothenburg]], [[Sweden]].]]
[[Image:Vandslinga Sparvag.jpg|right|thumbnail|Balloon loop at Linnéplatsen at the [[tram]]way in [[Gothenburg]], [[Sweden]].]]
[[Image:Platforms Olympic Park Sydney.svg|right|thumb|[[Spanish solution|Double sided]] [[island platform]] on a balloon loop - [[Olympic Park railway station, Sydney|Olympic Park, Sydney]], [[Australia]]<br />P1 & P4 departures<br />P2 & P3 arrivals]]
[[Image:Platforms Olympic Park Sydney.svg|right|thumb|[[Spanish solution|Double sided]] [[island platform]] on a balloon loop - [[Olympic Park railway station, Sydney|Olympic Park, Sydney]], [[Australia]]<br />P1 & P4 departures<br />P2 & P3 arrivals]]
[[Image:Diag15A18 MC&BCTE.png|right|thumb|Maules Creek & Boggabri Coal Terminal East balloon loops]]
[[Image:Diag15A18 MC&BCTE.png|right|thumb|Maules Creek & Boggabri Coal Terminal East balloon loops]]


A '''balloon loop''', '''turning loop''' or '''reversing loop''' ([[North American English]]) allows a rail vehicle or train to reverse direction without having to [[Shunting (rail)|shunt]] or stop. Balloon loops can be useful for passenger trains and [[Unit train|unit freight trains]].
A '''balloon loop''', '''turning loop''', or '''reversing loop''' ([[Glossary of North American railway terms|North American Terminology]]) allows a rail vehicle or train to reverse direction without having to [[Shunting (rail)|shunt]] or stop. Balloon loops can be useful for passenger trains and [[Unit train|unit freight trains]].


Balloon loops are common on [[tram|tram and streetcar]] systems. Many streetcar and tram systems use single-ended vehicles that have doors on only one side and controls at only one end. These systems may also haul trailers with no controls in the rear car, and, as such, must be turned at each end of the route.
Balloon loops are common on [[tram|tram and streetcar]] systems. Many streetcar and tram systems use single-ended vehicles that have doors on only one side and controls at only one end. These systems may also haul trailers with no controls in the rear car, and, as such, must be turned at each end of the route.
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=== Tramways ===
=== Tramways ===
[[File:Lechmere MBTA station loop in use-agr.webm|thumb|Light-rail train using the balloon loop at [[Lechmere station]] in [[Cambridge, Massachusetts]] USA in 2020]]
[[File:Lechmere MBTA station loop in use-agr.webm|thumb|Light-rail train using the balloon loop at [[Lechmere station]] in [[Cambridge, Massachusetts]], US in 2020]]


Balloon loops enable higher line capacity (faster turnaround of a larger number of trams) and allow the use of single-ended trams which have several advantages, including lower cost and more seating. However, double-ended trams also benefit from the capacity advantage of balloon loops. For example, on the former [[Sydney]] tram system, loops were used from 1881 until the second-generation system's closure in 1961. Initially, the Sydney system was operated by single-ended [[Steam trams in Sydney|steam trams]]; then from the 1890s by double-ended electric trams. Lines were looped in the Sydney CBD and the other busiest areas of operation, such as the eastern suburbs lines, as they provided greater turn-around capacity on the crowded system. The Sydney system was the first example of a tramway system using loops and has continued to build them up to 1997 (third-generation system). {{Citation needed|date = December 2021}}
On the former [[Sydney]] tram system, loops were used from 1881 until the second-generation system's closure in 1961. Initially, the Sydney system was operated by single-ended [[Steam trams in Sydney|steam trams]]; then from the 1890s by double-ended electric trams. Lines were looped in the Sydney CBD and the other busiest areas of operation, such as the eastern suburbs lines, as they provided greater turn-around capacity on the crowded system. The Sydney system was the first example of a tramway system using loops and has continued to build them up to 1997 (third-generation system). {{Citation needed|date = December 2021}}


Later in the 19th century, looped streetcar (tram) lines also began to appear on systems in the US, and soon looped operation with single-ended streetcars became widely used on many North American streetcar systems. European systems were almost universally converted to looped operation in the early 20th century, and most also adopted single-ended trams.{{Citation needed|date = December 2021}} Loops were also used on some tramways in Asia, South America and New Zealand, as well as on other Australian systems in addition to Sydney. Looped operation with single-ended trams is still the predominant method of tramway operation in the world{{Citation needed|date = December 2021}}, in spite of the recent construction of some new, typically smaller, stubbed systems with double-ended trams.
Later in the 19th century, looped streetcar (tram) lines also began to appear on systems in the US, and soon looped operation with single-ended streetcars became widely used on many North American streetcar systems. European systems were almost universally converted to looped operation in the early 20th century, and most also adopted single-ended trams.{{Citation needed|date = December 2021}} Loops were also used on some tramways in Asia, South America and New Zealand, as well as on other Australian systems in addition to Sydney. Looped operation with single-ended trams is still the predominant method of tramway operation in the world{{Citation needed|date = December 2021}}, in spite of the recent construction of some new, typically smaller, stubbed systems with double-ended trams.


==Advantages==
== Usage ==
Balloon loops are used extensively on [[tram]]way systems with single-ended trams. Usually located at termini, the loop may be a single one-way track round a block. Single-ended trams have a cab at only one end and doors on one side, making them cheaper and having more space for passengers. On tram systems with double-ended trams balloon loops are not required but may still be used as they can provide greater turn-around capacity than a stub terminus.

Balloon loops enable higher line capacity (faster turnaround of a larger number of trams) and allow the use of single-ended trams which have several advantages, including lower cost and more seating. However, double-ended trams also benefit from the capacity advantage of balloon loops.

Occasionally, balloon loops are used for reversing trains on lines with heavy grades and tight curves to equalize wear on both sides of locomotives and rollingstock. Such a balloon loop was constructed at Beech Forest on the {{RailGauge|2ft6in}} Victorian Railways line from Colac to Crowes.

=== Advantages ===
Advantages of a balloon loop include:
Advantages of a balloon loop include:


* Smooth operation
* Smooth operation
* Trains can arrive in any free platform, while another train is leaving any platform.
* Trains can arrive and leave simultaneously, as long as an open platform exists.
* Reversal of rolling stock helps even out wear and tear on the wheels.
* Reversal allows even wear and tear on the wheels.
* Eliminates need for brake test if locomotives uncoupled to carry out run around move.
* Eliminates the need for brake test if locomotives uncoupled to carry out run around the move.{{Clarify|date=December 2021}}


Compared to stations with stub platforms, balloon loops allow:
Compared to stations with stub platforms, balloon loops allow:


* Fewer tracks and platforms are required
* Fewer tracks and platforms are required.
* Arrivals into some platforms do not block departures from other platforms
* Arrivals into some platforms do not block departures from other platforms.
* Time is not lost while drivers change ends and reset the train for the other direction
* Time is not lost while drivers change ends and reset the train for the other direction.
* If the driver changed ends and discovers a hidden fault, then delays to trains are less likely
* If the driver changed ends and discovers a hidden fault, delays are less likely.


== Disadvantages ==
=== Disadvantages ===
Disadvantages of a balloon loop include:
Disadvantages of a balloon loop include:


* Very space consuming.
* Very space-consuming.
* The sharp curves cause noise, as well as wear on wheels and rails.
* The sharp curves cause noise, as well as wear on wheels and rails.
* If the platform is located on the curve, the gap between the platform and railcar door is a hazard.
* If the platform is located on the curve, the gap between the platform and railcar door is a hazard.
* On systems where, for reasons of economy, the couplings are made non-reversible (e.g. by fitting the air brake pipe along one side of the car only), the use of a balloon loop will cause a proportion of the rolling stock to face the "wrong" way and it may not be possible to assemble a complete train in a depot, even if sufficient cars are on hand. This was the case on the [[Charing Cross, Euston and Hampstead Railway]] (now part of the [[Northern line]] of [[London Underground]]).
* On systems, where, for reasons of economy, the couplings are made non-reversible (e.g. by fitting the air brake pipe along one side of the car only), the use of a balloon loop will cause a proportion of the rolling stock to face the "wrong" way and it may not be possible to assemble a complete train in a depot, even if sufficient cars are on hand.


=== Solutions ===
==== Solutions ====
[[File:WTC site from Fast Companys offices in 7WTC - 1 - May 2008.jpg|thumb|View of the balloon loop at the [[World Trade Center station (PATH)#Temporary_PATH_station|temporary PATH World Trade Center station]] from above.]]
* On many systems with a balloon loop the couplings and brake hoses are made reversible.
* At coal ports such as [[Kooragang#Kooragang Island|Kooragang]] in [[Newcastle, New South Wales]] the space inside the balloon loops is used for storing coal, so that it is not wasted.
* On many systems with a balloon loop, the couplings and brake hoses are made reversible.
* At coal ports such as [[Kooragang#Kooragang Island|Kooragang]] in [[Newcastle, New South Wales]] the space inside the balloon loops is used for storing coal so that it is not wasted.
* At the [[Olympic Park railway station, Sydney|Olympic Park station]] in Sydney, the loop is flattened where the platforms are located, so that the platform faces are straight.
* At the [[Olympic Park railway station, Sydney|Olympic Park station]] in [[Sydney Olympic Park]], the loop is flattened where the platforms are located, so that the platform faces are straight.
* After the opening of a loop at [[Embankment tube station|Charing Cross (Embankment)]] in 1914 (replaced in 1926 by the present [[Kennington tube station#Kennington loop|Kennington loop]]) car ends were marked "A" or "B" (later, when axles were designated by letters, the "B" car ends became "D" to match the adjacent axle), and it was not permitted to couple cars together if the ends to be coupled bore the same letter. It was found necessary to provide a [[Railway turntable|turntable]] at [[Golders Green tube station|Golders Green]] depot (near the other end of the line), for use when there was an imbalance of car directions.<ref>{{cite book|last=Bruce|first=J. Graeme|title=The London Underground Tube Stock|publisher=[[Ian Allan Publishing|Ian Allan]]|year=1988|isbn=0-7110-1707-7|location=Shepperton|pages=56–57|chapter=7. The First of the Standard Tube Stock 1923/25}}</ref>
* After the opening of a loop at [[Embankment tube station|Charing Cross (Embankment)]] in 1914 (replaced in 1926 by the present [[Kennington tube station#Kennington loop|Kennington loop]]) car ends were marked "A" or "B" (later, when axles were designated by letters, the "B" car ends became "D" to match the adjacent axle), and it was not permitted to couple cars together if the ends to be coupled bore the same letter. It was found necessary to provide a [[Railway turntable|turntable]] at [[Golders Green tube station|Golders Green]] depot (near the other end of the line), for use when there was an imbalance of car directions.<ref>{{cite book|last=Bruce|first=J. Graeme|title=The London Underground Tube Stock|publisher=[[Ian Allan Publishing|Ian Allan]]|year=1988|isbn=0-7110-1707-7|location=Shepperton|pages=56–57|chapter=7. The First of the Standard Tube Stock 1923/25}}</ref>
* The former [[South Ferry loops (New York City Subway)|South Ferry]] station on the [[New York City Subway]] solved the railcar door hazard by using [[gap filler]]s that extended out to the railcar door when the train triggered a switch on the tracks. The older station had been closed, but was reopened as a result of damage to the newer station caused by [[Hurricane Sandy]].
* The former [[South Ferry loops (New York City Subway)|South Ferry]] station on the [[New York City Subway]] solved the railcar door hazard by using [[gap filler]]s that extended out to the railcar door when the train triggered a switch on the tracks. The older station was closed in 2009, but was reopened between 2013 and 2017 as a result of damage to the newer station caused by [[Hurricane Sandy]].

== Examples ==
{{further|List of locations that use balloon loops}}
{{Cleanup list|section|date=November 2021}}

=== Passenger ===
[[Image:Bowling Green-South Ferry.png|thumb|150px|right|South Ferry balloon loop]]
On a balloon loop; the platform may be either curved or straight.

==== Australia ====
* [[Penfield railway line|Penfield]] - now closed and removed
* [[Outer Harbor railway line|Outer Harbor]] - now closed and removed
* [[Olympic Park railway station, Sydney|Olympic Park, Sydney]], [[Australia]]: platforms 1 and 4 are for boarding, 2 and 3 for alighting.
* [[Beech Forest railway station]], Victoria, [[Australia]]: single platform station on Victorian narrow gauge railway - now closed and removed.
* [[City Loop]], [[Melbourne]], [[Australia]]: Effectively four balloon loops with five stations: [[Flinders Street railway station|Flinders Street]], [[Southern Cross railway station|Southern Cross]], [[Flagstaff railway station|Flagstaff]], [[Melbourne Central railway station|Melbourne Central]] and [[Parliament railway station|Parliament]]

==== Austria ====
The tram systems in Vienna, Graz, Linz and Innsbruck employ Balloon Loops

==== Canada ====
* [[Toronto streetcar loops]]

==== France (Paris Métro) ====
* Non-passenger loops: [[Porte Dauphine (Paris Métro)|Porte Dauphine]] (line 2), [[Porte des Lilas (Paris Métro)|Porte des Lilas]] (line 3bis), [[Porte de Clignancourt (Paris Métro)|Porte de Clignancourt]] and [[Porte d'Orléans (Paris Métro)|Porte d'Orléans]] (line 4)
* Passenger loops: [[Nation (Paris Métro)|Nation]] (line 2), [[Charles de Gaulle – Étoile (Paris Métro and RER)|Charles de Gaulle – Étoile]] and Nation (line 6), [[Pré Saint-Gervais (Paris Métro)|Pré Saint-Gervais]] (line 7bis)
* The western end of line 10 is a long loop: trains arriving at [[Mirabeau (Paris Métro)|Mirabeau]] from [[Gare d'Austerlitz (Paris Métro)|Gare d'Austerlitz]] used to enter a loop with the following stations, [[Église d'Auteuil (Paris Métro)|Église d'Auteuil]], [[Michel-Ange – Auteuil (Paris Métro)|Auteuil]], [[Porte d'Auteuil (Paris Métro)|Porte d'Auteuil]] (official terminus), [[Michel-Ange – Molitor (Paris Métro)|Michel-Ange – Molitor]], [[Chardon Lagache (Paris Métro)|Chardon Lagache]] and Mirabeau again, to continue eastwards.
* There also are a few loops used for stabling trains, such as west of [[Invalides (Paris Métro)|Invalides]] and north of [[Porte de la Villette (Paris Métro)|Porte de la Villette]].

==== United Kingdom ====
{{Newcastle lines RDT|collapse=yes}}

* [[Dungeness railway station|Dungeness]], [[Romney, Hythe and Dymchurch Railway]], [[Kent]], [[England]]: single track, single platform for both boarding and alighting.<ref>{{cite map|publisher=Trackmaps|title=5 Southern & TfL|edition=3rd|date=November 2008|cartography=John Yonge|series=Railway Track Diagrams|page=18 Romney, Hythe & Dymchurch Railway|inset=E|isbn=978-0-9549866-4-3}}</ref>
* [[Merseyrail]], the Wirral Line underground loop under Liverpool, [[England]] (3 stations on loop)
* [[Ruislip Lido Railway]], a miniature railway in West London, [[England]]
* The [[Eurotunnel Shuttle]] uses balloon loops: since the two tracks cross over at the French end, the whole line forms a figure of 8 loop. This evens the wear on the train wheels.
* [[Newcastle railway station|Central station]] in [[Newcastle upon Tyne]] is on a loop, allowing trains from the South to arrive via the [[King Edward VII Bridge]] and return using the [[High Level Bridge, River Tyne|High Level Bridge]].
* [[Peasholm railway station|Peasholm]] on the [[Scarborough North Bay Railway|North Bay Railway]] in [[Scarborough, North Yorkshire|Scarborough]], [[North Yorkshire]] has a reverse balloon loop, with the "neck" of the balloon facing the buffer stop. The loop is used to allow the locomotive to run round the train and reverse at the same time.
* The first {{stnlnk|Wembley Stadium}} station in [[London]] (opened 1923, closed 1968) was on a balloon loop, but the modern-day station of that name is not.
* [[Barmouth Ferry railway station|Barmouth Ferry]] station on the [[Fairbourne Railway]] until closure due to sand movements on the loop made the loop unprofitable however the track still exists.
* [[Blackpool Tramway]] has a balloon loop at each end of the system ([[Starr Gate]] and [[Fleetwood]]) and at two intermediate points.
* The [[Charing Cross, Euston and Hampstead Railway]] (now part of the [[London Underground]]'s [[Northern line]]) constructed a single track balloon loop curving underneath the [[River Thames]] to serve its southern terminus of [[Embankment tube station]]. When the line was extended southwards to [[Morden tube station|Morden]] in 1926, the loop was sealed off.
* [[Kennington tube station#Kennington loop|Kennington station]], also on the [[Northern line]], has a balloon loop to the south of the station, which allows terminating southbound trains to turn around and reach the northbound platforms to form a return service.
* The [[Piccadilly line]] has a single track balloon loop (T4 loop) under [[Heathrow Airport]] connecting in order [[Hatton Cross tube station]], [[Heathrow Terminal 4 tube station]], [[Heathrow Terminals 1, 2, 3 tube station]] and back to Hatton Cross tube station.

====United States====
* [[Newark City Subway]] at [[Pennsylvania Station (Newark)|Penn Station]] and [[Hudson Bergen Light Rail]] at [[Tonnelle Avenue (HBLR station)|North Bergen]] in New Jersey
* [[Paulsboro Marine Terminal]], planned loop for dockside access<ref>{{cite web| title=Paulsboro - The New Omniport| publisher=South Jersey Port Corporation| url=https://www.youtube.com/watch?v=R2w_M4rs6l4 |archive-url=https://ghostarchive.org/varchive/youtube/20211213/R2w_M4rs6l4 |archive-date=2021-12-13 |url-status=live| format=video}}{{cbignore}}</ref>
* Formerly, the [[Streetcars in St. Louis|St. Louis streetcar system]] had several loop stations, which have left their names in city landmarks. These include the Hampton, Catalan, Wellston,<ref>{{Cite web|url=https://www.thewellstonloop.com/|title=Home|website=The Wellston Loop|access-date=2019-06-16}}</ref> and [[Delmar Loop|Delmar]] Loops. Although Delmar Boulevard now has a [[Loop Trolley|trolley route]], it no longer features a balloon loop at either end.
* [[Boston, Massachusetts|Boston]]:
** [[Bowdoin (MBTA station)|Bowdoin Station]] on the [[Massachusetts Bay Transportation Authority|MBTA]] [[Blue Line (MBTA)|Blue Line]] in [[Boston, Massachusetts|Boston]] has a wedge-shaped island platform inside a balloon loop. The boarding platform is long enough for only four cars, but all of the trains on the line are six cars so only the rear four can be boarded at Bowdoin.
** The MBTA [[Green Line (MBTA)|Green Line]], in Boston and suburbs, has balloon loops at several major stations. The loop at its [[Lechmere station]] operated from 1922 until 2020, when it was closed as part of extending the line.
** [[Mattapan (MBTA station)|Mattapan Station]] on the MBTA [[Ashmont–Mattapan High Speed Line]] in Boston, has trolley cars unload passengers at the platform, then uses a balloon loop to return to the same platform to load inbound passengers.
* [[California]]
** Union Pacific Railroad at [[Truckee, California]] - loop to avoid needing to reverse rotary snow plows<ref>{{cite web |url=http://truckeedonnerrailroadsociety.com/education/outreach/CLA.html |access-date=2012-05-01 |title=Truckee Donner Railroad Society |archive-url=https://web.archive.org/web/20120711191909/http://truckeedonnerrailroadsociety.com/education/outreach/CLA.html |archive-date=2012-07-11 |url-status=dead }}</ref>
** [[Judah and La Playa station]] is a balloon track that serves as the western terminus of the [[San Francisco Municipal Railway]] [[N Judah]] line.
** [[Wawona and 46th Avenue station]] is a balloon track that serves as the western terminus of the [[San Francisco Municipal Railway]] [[L Taraval]] line.
** The two terminal stations of [[North Hollywood (Los Angeles Metro station)|North Hollywood Station]] and [[Chatsworth (Los Angeles Metro station)|Chatsworth Station]] for the [[G Line (Los Angeles Metro)|G Line Metro Bus Transit]] of [[Los Angeles]], [[California]] have their platforms on a balloon loop.
{{multiple image
| direction = vertical
| width = 300
| footer = Grand Central Terminal track layouts, showing dual-level balloon loops
| image1 = RailUS GCT-lowerTracksPlan.gif
| alt1 =
| caption1 = Lower level (suburban)
| image2 = RailUS GCT-upperTracksPlan.gif
| alt2 =
| caption2 = Upper level (mainline)
}}
* [[New York City]]:
** [[City Hall (IRT Lexington Avenue Line)|City Hall]] [[New York City Subway|subway]] station on the [[IRT Lexington Avenue Line]] in [[New York City]] is now closed, although the loop track continues to be used to turn local trains. These trains discharge and take on passengers at [[Brooklyn Bridge – City Hall (IRT Lexington Avenue Line)|Brooklyn Bridge – City Hall]], one station to the north.
** [[South Ferry loops (New York City Subway)|South Ferry]] (see diagram) was a two-track subway loop station in New York City, with a sharply curved side platform for each track. Due to problems with train length and platform clearance, this station was replaced by a standard stub terminus with two tracks and an island platform ([[South Ferry (IRT Broadway – Seventh Avenue Line)|South Ferry]]), although the original trackage remains in use for turning trains. After the latter station was damaged in [[Hurricane Sandy]], the former station was reopened temporarily to provide service to the ferry terminal until the repairs to the latter station were completed.<ref>{{cite web|url=http://web.mta.info/capconstr/sft/|title=MTA Capital Construction - South Ferry Terminal Project|website=web.mta.info}}</ref>
** [[Grand Central Terminal]], [[New York City]] - stacked upper and lower level loops (lower loop has since been removed). The upper level loop track runs beyond track 38 (and a few others) to bring trains out on tracks 1, 2 (and others) on the East side Northbound.
** [[World Trade Center (PATH station)|World Trade Center]] station on the [[Port Authority Trans-Hudson|PATH]] subway system linking New York and New Jersey.
* [[Philadelphia]]:
** [[13th Street (SEPTA station)|13th Street]] (formerly Juniper Street) is the eastern terminus for the [[SEPTA Subway-Surface Lines]] in [[Philadelphia]], and trolleys turn on a balloon loop around [[Philadelphia City Hall]]
** [[Fern Rock Transportation Center|Fern Rock]] is the northern terminus for the [[Broad Street Line]] in Philadelphia, and rapid transit trains use a double-track balloon loop for turning & staging.
** [[Frankford and Delaware Avenue station]], also known as the Northern Liberties Loop, "temporary terminus" of the [[Girard Avenue Trolley]] while the [[Richmond-Westmoreland Streets Loop]] remains out of service.
* [[Virginia]]
** [[Broad Street Station (Richmond, Virginia)|Broad Street Station]] in [[Richmond, Virginia]] was the southern terminus of the [[Richmond, Fredericksburg and Potomac Railroad]] from 1917–1975 and had a loop that enabled RF&P trains to come in from the north, pick up / drop off passengers, and then head back north towards [[Washington, DC|Washington]]. The station closed in 1975 and the loop tracks have been abandoned.

====Other====
* Various stations of the [[Hong Kong Tramways]] and [[MTR]] [[Light Rail (Hong Kong)|Light Rail]]
* [[image:Stadtbahn Charleroi, Gleisplan 1997.png|thumb|300px|The [[Charleroi Pre-metro]] system features two balloon loops, at Beaux-Arts and Waterloo stations. This map is not current. Since 2013 there is a new connection between Sud and Park.]]In the [[Charleroi Pre-metro]], both the Beaux-Arts and Waterloo stations have balloon loops. At Beaux-arts, trains between Sud and Anderlues (line M1&M2, both directions) first run through the station on a platformless track, take the underground balloon loop then stop at the platform leading to their destination. Waterloo station service four lines (M1,2,3,4) going to three directions, on a single island platform. Trains from Gilly station either diverge to the right and end up at the station to continue to Parc station, or diverge to the left to end up on the other end of the island platform to go towards Beaux-Arts. At the station is also a bypass so trains can run from Gilly directly to Beaux-Arts, without halting at the platform. No scheduled trains thus fully run the loop (or the bypass).
* The [[Trams in Amsterdam|Amsterdam]], [[Rotterdam]] and [[The Hague]] tram systems have balloon loops at the end of nearly all lines. Amsterdam line 5 terminus at Amstelveen Binnenhof<ref>{{cite web| url=http://www.gvb.nl/english/travellers/maps/Pages/Combinomap.aspx| website=gvb.nl| title=Network plans and maps}}</ref> and The Hague lines branded as Randstadrail do not have balloon loops.(RandstadRail 4 and extra service 34 started to use turning loops later)(only in The Hague)<br />Across these cities there are several unused balloon loops that were in use until lines were extended or abolished. These loops however are still maintained for eventual purposes. But some have been removed.<br />The municipality of The Hague however plans on removing them and purchase new trams with a drivers cabin on both sides of the tram. (New trams have long since been installed and a number of turning loops have been removed) The new extension of the Utrecht Express tram has a loop at De Uithof.
* The [[Saitama, Saitama|Saitama]] [[New Shuttle]] has a balloon loop at [[Ōmiya Station (Saitama)|Ōmiya]].

'''Multiple stations on a balloon loop:'''
* [[Heathrow Terminal 4 tube station|Heathrow Terminal 4]] and [[Heathrow Terminals 1, 2, 3 tube station|Terminals 1,2,3]] stations on the [[Piccadilly line]] of [[London Underground]].<ref>{{cite map |publisher=Trackmaps |title=5 Southern & TfL |edition=3rd |date=November 2008 |cartography=John Yonge |series=Railway Track Diagrams |page=43 Piccadilly line: South Harrow & Heathrow - Acton Town |inset=D |isbn=978-0-9549866-4-3 }}</ref>
* The [[LACMTA]] [[A Line (Los Angeles Metro)|A Line]] has four stations on its loop through downtown [[Long Beach, California|Long Beach]] ([[California]]).
* In [[Liverpool]], [[England]], on the [[Wirral Line]] of the [[Merseyrail#Lines|Merseyrail]] network, trains arriving at Liverpool through the [[Mersey Railway|Mersey Tunnel]] fork left at Mann Island Junction onto a balloon loop, before reaching [[Liverpool James Street railway station|James Street]] (platform 1); they then call at deep-level platforms at {{stnlnk|Moorfields}}, {{stnlnk|Liverpool Lime Street}} and {{stnlnk|Liverpool Central}} before reaching James Street again (platform 3), then rejoin the original route at [[Mann Island]] Junction and then pass back through the Mersey tunnel.<ref>{{cite map |publisher=Trackmaps |title=4 Midlands & North West |edition=2nd |date=March 2005 |cartography=John Yonge |series=Railway Track Diagrams |page=40 Hunts Cross - Moorfields |isbn=0-9549866-0-1 }}</ref>
* The [[City Loop]] or [[MURLA|Melbourne Underground Rail Loop]], Melbourne, Australia, has five stations. There a four loops, one from the north east and three from the south west, on two levels. The loops are bi-directional. A connection enables one of the south east loops to be used as a circle line. There are no connections between the four loops.
* In the city of [[Vantaa]], [[Finland]], in the [[Greater Helsinki]] area, the [[Kehärata]] or [[Ring Rail Line]] of [[Helsinki commuter rail]] built between an existing branch at [[Vantaankoski railway station|Vantaankoski]] and the main line at [[Tikkurila railway station|Tikkurila]] opened on July 1, 2015. The line primarily serves the [[Helsinki Airport|airport]] which was before only accessible by road, and new suburbs and working areas being built along the line. An existing stopping service to Vantaankoski station was replaced by a service which traverses the whole loop and returns to [[Helsinki central railway station|Helsinki]], stopping twice on opposite sides of [[Pasila railway station|Pasila]] station. Five new stations were built, but the loop has a total of 22 stations, not counting Pasila or Helsinki. Roughly half of these stations are on the northbound and westbound mainlines, the loop line leaving them via [[flying junction|diving junctions]] at [[Hiekkaharju railway station|Hiekkaharju]] and [[Huopalahti railway station|Huopalahti]].
* [[Rapid Metro Gurgaon]] in India.
* [[Minami-Kōen Station|Minami-Kōen]], Naka Futō, and Kita Futō stations on the [[Port Island Line]] in [[Kōbe]].
* The [[Yamaman Yūkarigaoka Line]] has three stations on its balloon loop: Joshidai, Chūgakkō, and Ino.
*In [[Singapore]], the [[Bukit Panjang LRT line]] has 7 stations from [[Petir LRT station|Petir]] to [[Senja LRT station|Senja]] on a bidirectional balloon loop emerging from [[Bukit Panjang MRT/LRT station|Bukit Panjang station]], with alternate trains plying each direction of the loop.

'''With balloon loop:'''
The balloon loop is past the station.
[[Image:City Hall station plan.jpg|thumb|300px|right|Brooklyn Bridge and City Hall stations in New York City.]]

* [[Bad Herrenalb]], Albtalbahn, Germany: the train passes the loop before arrival
* [[Bowling Green (IRT Lexington Avenue Line)|Bowling Green]] on New York City's IRT Lexington Avenue subway line is the southern terminus for '''{{NYCS Lexington South Ferry}}''' service in the evenings & on weekends, with the South Ferry inner loop (see previous section) used to turn trains.
* [[Brooklyn Bridge – City Hall (IRT Lexington Avenue Line)|Brooklyn Bridge – City Hall]], also on New York City's IRT Lexington Avenue Line, is the southern terminus for Lexington Avenue local service (the '''{{NYCS City Hall}}''' trains), with the City Hall loop (see previous section) used to turn trains.
* [[Howard (CTA)|Howard Station]] on the [[Red Line (Chicago Transit Authority)|CTA Red Line]] in [[Chicago]] uses a balloon loop to turn a northbound train back south. Because the other end of the line does not contain a loop, the wear on the wheels is evened out after two trips.
* The [[Irish Steam Preservation Society|Irish Steam Preservation Society's]] line at [[Stradbally]], [[County Laois|Co.Laois]], [[Ireland]] consists of a balloon loop: trains operate from the station and back again via the loop.
* [[69th Street Terminal]], the western terminus of the [[SEPTA]] [[Market–Frankford Line]] in [[Philadelphia]]: westbound trains discharge passengers at the platform and go around the loop to one of two eastbound platforms to pick up passengers.
* [[Gateway Center (PAT station)|Gateway Center]] in Pittsburgh used to be the north/west end of the [[Pittsburgh Light Rail]] line. Westbound trains would discharge passengers at the inbound platform, then go around a loop to the outbound platform to pick up passengers. When [[North Shore Connector|the subway was extended]] in 2009–2012, the loop was removed; while the original outbound platform under Liberty Ave was left intact, the inbound platform was demolished and moved.
* [[Kennington tube station]], on the [[London Underground]]'s [[Northern line]]: trains from the Charing Cross branch can terminate at Kennington and then run around a loop to return north. Trains from the Bank branch cannot use this loop.
* [[Stuttgart Schwabstraße station|Schwabstraße station]] on the [[Stuttgart S-Bahn]]: the loop is south of the station and completely underground
* [[Tonnelle Avenue (HBLR station)]]: the loop is to the west of the station.

==== Tram systems ====
Balloon loops are used extensively on [[tram]]way systems with single-ended trams. Usually located at termini, the loop may be a single one-way track round a block. Single-ended trams have a cab at only one end and doors on one side, making them cheaper and having more space for passengers. On tram systems with double-ended trams balloon loops are not required but may still be used as they can provide greater turn-around capacity than a stub terminus; the [[Birmingham Corporation Tramways]] terminus at [[Rednal]] had a balloon loop in addition to the conventional stub tracks, providing extra capacity to handle weekend and bank holiday crowds visiting the nearby [[Lickey Hills]].
The [[Milan]] interurban tramway network, although using double-ended trams, had balloon loops at termini within the city limits so that they could be used as backup termini by the single directional trams used on urban service.
Another example is in [[Potsdam]], [[Germany]].

=== Freight ===

====Australia====
; Queensland
* [[Port of Brisbane]]: Freight, [[dual gauge]]
* [[Pinkenba]] Freight and special steam services.
'''''Loading loops'''''
; New South Wales
* Coal
** [[Camberwell, New South Wales|Camberwell]]: Coal
** [[Craven, New South Wales|Craven]]: Coal
** [[Fassifern]]: Coal - has triangle as well, so trains can go north or south
** [[Gunnedah]]: Coal
** [[Boggabri]] Coal
** Maules Creek
** Boggabri Coal Terminal East
** Mount Thorley: and other mines - coal
** Newdell Junction: Coal - has two balloon loops for different coal mines
** Newnes Junction coal loader
** [[Tahmoor, New South Wales|Tahmoor]]: Coal - due to change in operational requirements, the balloon loop now points the wrong way, and requires trains to be [[top and tail]]ed.
** [[Ulan, New South Wales|Ulan]]: Coal
** Wilpinyong: Coal
* Wheat
** Penny Road, near [[Moree, New South Wales|Moree]]: Wheat

; Queensland
* [[Owanilla]], Maryborough South;<ref>{{cite magazine| magazine=Railway Digest| date=October 2014| page=14}}</ref> includes a circle inside the balloon to allow inspection before unloading/loading!<ref>{{cite web|url=http://www.railpage.com.au/f-p1941766.htm#1941766|title=Owanilla Balloon Loop|website=Railpage}}</ref>

; South Australia
* [[Marree railway line]] at the [[Telford Cut]] coal mine, [[Leigh Creek, South Australia|Leigh Creek]] until 2016
* [[Wirrida]], [[Adelaide-Darwin Railway]] - iron ore<ref>{{cite magazine| magazine=[[Railway Digest]]| date=February 2013| page=54}}</ref><ref>{{Cite web |url=http://www.sa-trackandsignal.net/Pdf%20files/SACountry/NT1811.pdf |title=Map: Standard gauge track Northgate-Wirrida|access-date=2015-02-02 |archive-url=https://web.archive.org/web/20160304080706/http://www.sa-trackandsignal.net/Pdf%20files/SACountry/NT1811.pdf |archive-date=2016-03-04 |url-status=dead }}</ref>
* [[Mallala, South Australia|Mallala]] AWB Grain Loop
* [[Crystal Brook, South Australia|Crystal Brook Grain Loop]]<ref>{{cite web| url=http://www.sa-trackandsignal.net/Pdf%20files/ARTC/AR079.pdf| title=Map: Standard gauge track Crystal Brook| website=SA Track and Signal}}</ref>

; Western Australia
* Koolyanobbin East (iron ore)<ref>{{cite web| url=http://www.sa-trackandsignal.net/Pdf%20files/Brookfield/BR856.pdf| title=Map: Standard gauge track Koolyanobbing East-Koolyanobbing| website=SA Track and Signal}}</ref>

----
'''''Unloading loops'''''
; New South Wales
* [[Eraring]] - power station
* Vales Point: power station ; Coal unloader
* Port Waratah: Coal & Wheat unloader at port
* [[Kooragang#Kooragang Island|Koorang Island]]: Coal unloader at port
* Port Kembla - coal and wheat

; South Australia

* [[Whyalla]] iron ore export [[dual gauge]]<ref>{{cite web| url=http://www.railexpress.com.au/archive/2012/november/november-7th-2012/top-stories/arrium-calls-for-interstate-track-upgrade/?searchterm=None| title=Balloon loop| archive-url=https://web.archive.org/web/20131203010002/http://www.railexpress.com.au/archive/2012/november/november-7th-2012/top-stories/arrium-calls-for-interstate-track-upgrade/?searchterm=None | archive-date=2013-12-03 }}</ref>
*[[Port Augusta, South Australia|Port Augusta]] coal power stations until 2016

; Victoria
* [[Geelong]] dual-gauge grain loop at [[Port of Geelong|port]]<ref>{{cite web|title=Grain Loop|url=http://www.railgeelong.com/location/grain-loop|publisher=Rail Geelong|access-date=2013-12-28}}</ref>

; West Australia
* Yarrie: Iron ore<ref>{{cite web|url=http://www.street-directory.com.au/sd_new/mapsearch.cgi?star=5&heading=&x=120.27979366673421&y=-20.581211070081974&level=4&StateID=3|title=Australia Map Directory of Western Australia WA of Street-directory.com.au|website=www.street-directory.com.au|access-date=2010-08-04|archive-url=https://web.archive.org/web/20110611134107/http://www.street-directory.com.au/sd_new/mapsearch.cgi?star=5&heading=&x=120.27979366673421&y=-20.581211070081974&level=4&StateID=3|archive-date=2011-06-11|url-status=dead}}</ref>
* Koolyanobbing: Iron Ore
* Pinjarra: Alumina<ref name="auto">{{cite magazine| magazine=[[Railway Digest]]| date=October 2014| page=38}}</ref>
* Kwinana: N/A<ref name="auto"/>
* Bunbury: N/A<ref name="auto"/>

==== Africa ====
* [[Catete (Bengo)|Catete]], [[Angola]]
* Klipdale, South Africa, on the [[Overberg branch line]], to allow trains from [[Cape Town]] to continue to [[Bredasdorp]] (and vice versa) without shunting.
* [[Port Pepel]], [[Sierra Leone]] - proposed iron ore export<ref>{{cite web|url=http://www.african-minerals.com/operations/maps|title=african-minerals.com - african-minerals Resources and Information.|website=www.african-minerals.com|access-date=2014-03-28|archive-url=https://web.archive.org/web/20140328084111/http://www.african-minerals.com/operations/maps|archive-date=2014-03-28|url-status=dead}}</ref>
* [[Dimbokro]], [[Ivory Coast]] {{coord|06|38|42|N|04|42|22|W}}<ref>{{cite web|url=http://www.mapquest.com/ivory-coast/dimbokro-283509398|title=Dimbokro - MapQuest|website=mapquest.com}}</ref>

==== Germany ====
* [[Selke Valley Railway]] (German: Selketalbahn): Part of the {{RailGauge|1000mm}} gauge [[Harz Narrow Gauge Railways]] (German: Harzer Schmalspurbahnen). A balloon loop has been constructed at [[Stiege]] to allow freight trains between [[Nordhausen, Thuringia|Nordhausen]] and the power station at [[Silberhütte (Harzgerode)]] to make their journeys without the locomotive having to [[Headshunt|run round]]. Passenger trains continue along the branch beyond [[Stiege]] to [[Hasselfelde]] where they reverse.

==== Iran ====
Has several balloon loops and triangles.

====New Zealand====
* [[Dargaville Branch]]: Balloon loop providing access to Kirikopuni, 2&nbsp;km north of the main line. This was eliminated by a bypass in 1943.
* [[Woodville, New Zealand|Woodville]]: Balloon loop linking the [[Wairarapa Line]] and the [[Palmerston North - Gisborne Line]] so that trains running between the [[Wairarapa]] and [[Hawke's Bay]] do not have to reverse. Unlike a triangle, the balloon loop enables these trains to serve Woodville station.
* Lyttelton Coal unloading rail facility.

====United Kingdom====
There are several balloon loops at [[power station]]s in the UK; these have been provided so that [[coal]] trains may unload without stopping (known as the ''[[Merry-go-round train|merry-go-round]]'' system). Examples include [[Cottam Power Station|Cottam]], [[Didcot Power Station|Didcot]], [[Drax Power Station|Drax]], [[Eggborough Power Station|Eggborough]], [[Ferrybridge power station|Ferrybridge]], and [[Ratcliffe-on-Soar Power Station|Ratcliffe-on-Soar]].

Also, the [[Fife Circle]] line between [[Edinburgh]] and the county of [[Fife]] acts like a giant balloon loop, branching off after Inverkeithing and connecting again at Kirkcaldy.

Also, two [[London Underground]] lines have balloon loops; the [[Northern Line]] has one at [[Kennington tube station|Kennington]], where trains can terminate, drive around the reversing loop, and then start again whilst others can pass through; whereas the [[Piccadilly Line]] has one serving Terminal 4 of [[Heathrow Airport]] (half of all trains use this loop to return eastwards back into London, while trains terminating at Terminal 5 must halt and reverse).

====United States====
* Louisa Generating Station: Coal unloader, south of [[Muscatine, Iowa]]
* [[National City, California]]: Balloon Loop near San Diego Bay
* [[San Francisco Transbay Terminal]] was a balloon loop for the [[Key System]] before it was abandoned
* [[Marias Pass]], [[Montana]]: balloon loop on the [[BNSF]]'s [[Northern Transcon]] line. It replaced a wye at the same spot.
* [[Donner Pass]], [[California]]: there is balloon loop on either side of the pass. One is in [[Truckee]] and the other near [[Blue Canyon, California|Blue Canyon]]. They are primarily used to facilitate snow removal, allowing the plows and blowers to easily be returned over the pass.
* [[Grayling Army Airfield]], [[Grayling, Michigan]]: Balloon loop to support logistics moves of Army units training at [[Camp Grayling]].

====Other====
Both the French and the British terminals of the [[Eurotunnel Shuttle]] service through the [[Channel Tunnel]] consist of balloon loops, in opposite directions to even out wear on the wheels.

Occasionally, balloon loops are used for reversing trains on lines with heavy grades and tight curves to equalise wear on both sides of locomotives and rollingstock. Such a balloon loop was constructed at Beech Forest on the {{RailGauge|2ft6in}} Victorian Railways line from Colac to Crowes.


== References ==
== References ==

Latest revision as of 20:58, 21 September 2024

Balloon loop at Linnéplatsen at the tramway in Gothenburg, Sweden.
Double sided island platform on a balloon loop - Olympic Park, Sydney, Australia
P1 & P4 departures
P2 & P3 arrivals
Maules Creek & Boggabri Coal Terminal East balloon loops

A balloon loop, turning loop, or reversing loop (North American Terminology) allows a rail vehicle or train to reverse direction without having to shunt or stop. Balloon loops can be useful for passenger trains and unit freight trains.

Balloon loops are common on tram and streetcar systems. Many streetcar and tram systems use single-ended vehicles that have doors on only one side and controls at only one end. These systems may also haul trailers with no controls in the rear car, and, as such, must be turned at each end of the route.

History

[edit]

Balloon loops were first introduced on tram and, later, metro lines. They did not commonly appear on freight railways until the 1960s, when the modernising British Rail system introduced merry-go-round (MGR) coal trains that operated from mines to power stations and back again without shunting.[citation needed]

Tramways

[edit]
Light-rail train using the balloon loop at Lechmere station in Cambridge, Massachusetts, US in 2020

On the former Sydney tram system, loops were used from 1881 until the second-generation system's closure in 1961. Initially, the Sydney system was operated by single-ended steam trams; then from the 1890s by double-ended electric trams. Lines were looped in the Sydney CBD and the other busiest areas of operation, such as the eastern suburbs lines, as they provided greater turn-around capacity on the crowded system. The Sydney system was the first example of a tramway system using loops and has continued to build them up to 1997 (third-generation system). [citation needed]

Later in the 19th century, looped streetcar (tram) lines also began to appear on systems in the US, and soon looped operation with single-ended streetcars became widely used on many North American streetcar systems. European systems were almost universally converted to looped operation in the early 20th century, and most also adopted single-ended trams.[citation needed] Loops were also used on some tramways in Asia, South America and New Zealand, as well as on other Australian systems in addition to Sydney. Looped operation with single-ended trams is still the predominant method of tramway operation in the world[citation needed], in spite of the recent construction of some new, typically smaller, stubbed systems with double-ended trams.

Usage

[edit]

Balloon loops are used extensively on tramway systems with single-ended trams. Usually located at termini, the loop may be a single one-way track round a block. Single-ended trams have a cab at only one end and doors on one side, making them cheaper and having more space for passengers. On tram systems with double-ended trams balloon loops are not required but may still be used as they can provide greater turn-around capacity than a stub terminus.

Balloon loops enable higher line capacity (faster turnaround of a larger number of trams) and allow the use of single-ended trams which have several advantages, including lower cost and more seating. However, double-ended trams also benefit from the capacity advantage of balloon loops.

Occasionally, balloon loops are used for reversing trains on lines with heavy grades and tight curves to equalize wear on both sides of locomotives and rollingstock. Such a balloon loop was constructed at Beech Forest on the 2 ft 6 in (762 mm) Victorian Railways line from Colac to Crowes.

Advantages

[edit]

Advantages of a balloon loop include:

  • Smooth operation
  • Trains can arrive and leave simultaneously, as long as an open platform exists.
  • Reversal allows even wear and tear on the wheels.
  • Eliminates the need for brake test if locomotives uncoupled to carry out run around the move.[clarification needed]

Compared to stations with stub platforms, balloon loops allow:

  • Fewer tracks and platforms are required.
  • Arrivals into some platforms do not block departures from other platforms.
  • Time is not lost while drivers change ends and reset the train for the other direction.
  • If the driver changed ends and discovers a hidden fault, delays are less likely.

Disadvantages

[edit]

Disadvantages of a balloon loop include:

  • Very space-consuming.
  • The sharp curves cause noise, as well as wear on wheels and rails.
  • If the platform is located on the curve, the gap between the platform and railcar door is a hazard.
  • On systems, where, for reasons of economy, the couplings are made non-reversible (e.g. by fitting the air brake pipe along one side of the car only), the use of a balloon loop will cause a proportion of the rolling stock to face the "wrong" way and it may not be possible to assemble a complete train in a depot, even if sufficient cars are on hand.

Solutions

[edit]
View of the balloon loop at the temporary PATH World Trade Center station from above.
  • On many systems with a balloon loop, the couplings and brake hoses are made reversible.
  • At coal ports such as Kooragang in Newcastle, New South Wales the space inside the balloon loops is used for storing coal so that it is not wasted.
  • At the Olympic Park station in Sydney Olympic Park, the loop is flattened where the platforms are located, so that the platform faces are straight.
  • After the opening of a loop at Charing Cross (Embankment) in 1914 (replaced in 1926 by the present Kennington loop) car ends were marked "A" or "B" (later, when axles were designated by letters, the "B" car ends became "D" to match the adjacent axle), and it was not permitted to couple cars together if the ends to be coupled bore the same letter. It was found necessary to provide a turntable at Golders Green depot (near the other end of the line), for use when there was an imbalance of car directions.[1]
  • The former South Ferry station on the New York City Subway solved the railcar door hazard by using gap fillers that extended out to the railcar door when the train triggered a switch on the tracks. The older station was closed in 2009, but was reopened between 2013 and 2017 as a result of damage to the newer station caused by Hurricane Sandy.

References

[edit]
  1. ^ Bruce, J. Graeme (1988). "7. The First of the Standard Tube Stock 1923/25". The London Underground Tube Stock. Shepperton: Ian Allan. pp. 56–57. ISBN 0-7110-1707-7.
[edit]
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