Tram Turnback Loops

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Western 52

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Mod Note: Posts #1 - #13 originally in this thread.

In Prague most of the tram routes end in turn back loops as most of the trams are single ended. There are also a number of intermediate turn back loops for trams which don't travel the whole route. From memory the tram routes in Oslo also have these loops on some routes.
 
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Mag_seven

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In Prague most of the tram routes end in turn back loops as most of the trams are single ended

Same in Zurich

And just to be pedantic when it comes to trams isn't the correct term "turning circle" rather than "turn back loop"?
 

Whisky Papa

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In Prague most of the tram routes end in turn back loops as most of the trams are single ended. There are also a number of intermediate turn back loops for trams which don't travel the whole route. From memory the tram routes in Oslo also have these loops on some routes.
Not all of Prague's additional turnback locations have loops. I recall killing a few minutes watching single-ended trams being shunted round this triangle at Zvonařka during planned engineering works (I think it was peak-hour route 4, but could be mistaken after 8 years!). On a more recent visit, the additional tourist service 23 up past the castle was terminating here, again using single-ended trams - actually the oldest members of the T3 fleet :D .

Edited to include GSV link - oops.
 

Western 52

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Not all of Prague's additional turnback locations have loops. I recall killing a few minutes watching single-ended trams being shunted round this triangle at Zvonařka during planned engineering works (I think it was peak-hour route 4, but could be mistaken after 8 years!). On a more recent visit, the additional tourist service 23 up past the castle was terminating here, again using single-ended trams - actually the oldest members of the T3 fleet :D .

Edited to include GSV link - oops.
Yes I'd forgotten the 23 route turning on that triangle. I think that route still uses Tatra T3 trams in near original condition, at least it did in 2018.
 

Taunton

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And just to be pedantic when it comes to trams isn't the correct term "turning circle" rather than "turn back loop"?
Certainly called loops in the USA, including by the local population.

The standard tram ("streetcar") built in the USA from the late 1930s to the 1950s, the PCC, was single-ended, so the cities that bought these (which was most significant systems) did work laying in loops at all termini and various intermediate points. The termini ones were often quite substantial, with sidings, waiting shelter, a café in the middle, and off-street provision for transfer to buses. If you wanted these waiting facilities to be in the middle the cars have to have the loop arranged to run "wrong way round" to put the doors on the correct side.
 

MontyP

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Yes I'd forgotten the 23 route turning on that triangle. I think that route still uses Tatra T3 trams in near original condition, at least it did in 2018.
Some Helsinki tram routes have them - there is definitely one at the southern end of the 6.
 

dm1

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I think if you start including tram reversing loops in the list, it will get very long, very quickly. I'd guess that a very signficant proportion of tram systems worldwide use single-ended trams, so will have numerous reversing loops (at the terminus of each line, and likely several more at strategic locations as well)
 

Whisky Papa

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Certainly called loops in the USA, including by the local population.

The standard tram ("streetcar") built in the USA from the late 1930s to the 1950s, the PCC, was single-ended, so the cities that bought these (which was most significant systems) did work laying in loops at all termini and various intermediate points. The termini ones were often quite substantial, with sidings, waiting shelter, a café in the middle, and off-street provision for transfer to buses. If you wanted these waiting facilities to be in the middle the cars have to have the loop arranged to run "wrong way round" to put the doors on the correct side.
One odd loop layout is at Divoká Šárka on the NW outskirts of Prague, where there is a double-track loop which trams from the two different terminating routes traverse in opposite directions and then load at separate stops. Most of their other loops I've been to split into two tracks that either have parallel loading stops (eg Bilá Hora) or recombine before reaching one common stop (eg Sídlišté Petřiny). Nothing much in the way of facilities for passengers you may notice, only a toilet block for the drivers.
 

Ken H

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Brussels tram line 44 has one at each end. the Montgomery ones are in tunnel. When I lived there they had one ended trams. I think some Berlin trams are one ended too.
 

edwin_m

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Evesham vale Light railway has one.

Brussels tram line 44 has one at each end. the Montgomery ones are in tunnel. When I lived there they had one ended trams. I think some Berlin trams are one ended too.


I thought of that one, and looked on google maps. i think its gone.
Most trams in mainland Europe are probably single-ended so require turnback loops. They never caught on in the UK, though Rotherham had some that looked like trolleybuses on rails. Newer tramways tend to use double-ended trams instead, probably because it's difficult to provide loops everywhere they might be needed and modern systems have to be accessible so can't get away with a tightly-curved platform on the loop.
 
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Most trams in mainland Europe are probably single-ended so require turnback loops. They never caught on in the UK, though Rotherham had some that looked like trolleybuses on rails. Newer tramways tend to use double-ended trams instead, probably because it's difficult to provide loops everywhere they might be needed and modern systems have to be accessible so can't get away with a tightly-curved platform on the loop.
I suspect another reason for using double-ended trams is that segregated tracks (e.g. underground sections) may require doors on both sides of the vehicle for maximum flexibility in the design of the stops/stations, and once you accept that, it removes a major advantage of single-ended vehicles.
 

edwin_m

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I suspect another reason for using double-ended trams is that segregated tracks (e.g. underground sections) may require doors on both sides of the vehicle for maximum flexibility in the design of the stops/stations, and once you accept that, it removes a major advantage of single-ended vehicles.
Indeed. Vehicles for pre-metro and networks more towards the light rail end of the spectrum are pretty universally double-ended. I believe Hannover has (or had) some single-ended vehicles with doors both sides, but these run in pairs coupled back to back.
 

dm1

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The main advantage of single-ended trams over double-ended (very, very broadly speaking) is the additional seating capacity you can get by placing seats where the doors and rear cab would otherwise be. Modern low-floor trams tend to have comparatively few seats inside, so this does make a noticable difference.

However, for the reasons stated above, new-built systems don't tend to use them nowadays.
 

vlad

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I suspect another reason for using double-ended trams is that segregated tracks (e.g. underground sections) may require doors on both sides of the vehicle for maximum flexibility in the design of the stops/stations, and once you accept that, it removes a major advantage of single-ended vehicles.

Things may have changed since I was there last but...:

Trams in Volgograd are single-ended with the doors on the right-hand side, similar to pretty much all trams in Russia. However, one of the lines runs in tunnel under the town centre. As the stations have island platforms (again, similar to stations on "real" metro systems), trams have to run on the left-hand side through these stations so the doors can actually be used!
 

MarcVD

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Brussels tram line 44 has one at each end. the Montgomery ones are in tunnel. When I lived there they had one ended trams. I think some Berlin trams are one ended too.
The whole tram network in Brussels used to be operated with single ended trams, so each line had a loop or a triangle - usually named ”chapeau de curé” in french - at each end. Today, all Brussels trams are bi directional so those loops and triangles disappear. Lines 39 and 44 were the last ones to use the series 7000 single ended trams so even today there is still a loop in Montgomery and Tervuren, and a triangle in Ban Eik.

The main advantage of bi directional trams is ease of operation. Not only you can board the tram from both sides, so when the line runs on a separate reservation, you can have stops with a common platform between the two tracks, but also you can reverse with just a pair of switches, which are much simpler and cheaper to install than a reversing loop, and you can use them in both directions. Its even possible to install temporary switches that you lay on top of the running rails just for the time of an interruption for engineering works.

And finally, the single ended trams were also preferred in the US because it seems culturally unacceptable over there to travel seating backwards. Single ended trams can have all seats facing forward. This was, and still is, the case of the Belgian coastal tramway which is still using terminal and intermediate loops.
 

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There are many of these loops in Amsterdam, one at each end point except those on the lines to IJburg and Amstelveen which are operated by bi-directional trams. Also Rotterdam and The Hague have many loops as I believe all trams in Rotterdam are unidirectional and most in The Hague are.
 

plugwash

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I would think another issue with single ended trams is what happens if there is a line blocking incident in a non-street running area, or worse a tunnel and want to reverse back to a more suitable location for evacuation.

Though I guess single locomotive hauled heavy rail trains suffered from the same issue.
 

jamesontheroad

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This could quickly become a one-way thread where people list examples without much interaction with one another. At this of making this worse I can share this page on Wikipedia which lists (in very precise detail, down to the decimetre of each loop radius) all the turning loops of the TTC Streetcar system in Toronto.

The interchange at Union Station is one of the most interesting, since streetcars on 509 and 510 use an underground loop which allows fairly easy connection to the passage between the train station platforms.

I only used it once, just after arriving in Toronto, and I wasn’t quite sure what was going on. The platform is a gracious curve, with bright colours painted on the floor to stop you standing where the overhanging front or back of the turning tram could smack you on its way it out.
 

Austriantrain

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I would think another issue with single ended trams is what happens if there is a line blocking incident in a non-street running area, or worse a tunnel and want to reverse back to a more suitable location for evacuation.

Single-ended trams are still able to go backwards. Vienna e.g. is all single-ended with tram loops, but of course they can reverse and sometimes have to; mostly in depots. They have „emergency driving controls“ on the rear end which can be used for this.
 

edwin_m

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Single-ended trams are still able to go backwards. Vienna e.g. is all single-ended with tram loops, but of course they can reverse and sometimes have to; mostly in depots. They have „emergency driving controls“ on the rear end which can be used for this.
Even when they can be crossed to the correct track they have the problem of doors on the wrong side, so it's generally impossible to run a "part route" with single ended trams unless there is a turning circle at the temporary terminating point, or at least a street layout that allows trams to be turned easily. Some tramways that normally run all routes with turning loops each end have a small number of double-ended trams, which form part of the normal fleet but can be used when a route is temporarily part-closed.
 

Gag Halfrunt

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Things may have changed since I was there last but...:

Trams in Volgograd are single-ended with the doors on the right-hand side, similar to pretty much all trams in Russia. However, one of the lines runs in tunnel under the town centre. As the stations have island platforms (again, similar to stations on "real" metro systems), trams have to run on the left-hand side through these stations so the doors can actually be used!

The line now has bidirectional trams. Here's a photo showing right-hand running at a station with an island platform.

 

Taunton

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As the stations have island platforms (again, similar to stations on "real" metro systems), trams have to run on the left-hand side through these stations so the doors can actually be used!
That's been an approach at various places round the world.

The downsides of double-ended trams are the waste of space on the offside and rear end of the vehicle, and the need for twice as many expensive and fragile items; the doors; the driving cab, etc. Notably nobody has ever seen the need for double-ended buses.
 

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The Belgian Coastal Tram used to be operated solely by single ended trams, and there are still turning circles at Knokke and De Panne.

However new bi-directional low floor trams have been introduced, and eventually the single ended trams will all be replaced.
 

edwin_m

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The downsides of double-ended trams are the waste of space on the offside and rear end of the vehicle, and the need for twice as many expensive and fragile items; the doors; the driving cab, etc. Notably nobody has ever seen the need for double-ended buses.
Which has to be set against the cost and space needed for turnback loops, plus the risk of noise as the vehicles make these tight turns which can't be used for accessible platforms. To realise the cost saving from single-ended trams every turnback location on the route, and ideally in the whole city, needs to find a solution to these problems.

Space on the offside isn't really wasted, as it can be used by standing passengers. And the cost of a second cab may not be that high considering that the tram has to have all the controls and their circuits anyway, for reversing in emergency or within the depot.
 

Taunton

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This sounds like the traditional approach, where the infrastructure provider does their own cheapest solution, and sticks the resulting issues on the vehicle providers and the operators.

To avoid doubt, the purpose of the whole system is to transport passengers - and among them a key concern is commonly "getting a seat". It's all very well for the transport management bubble to eulogise about "well you can stand there", forgetting the bit about having to hold on tightly to whatever handholds the budget ran to, while it lurches along. The single car PCC in the USA used to typically have 61 seats, to get to the length of a typical European 2021 unit just multiple two together. 122 seats. You are lucky to get half that number of seats however in a current LRV.
 

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This sounds like the traditional approach, where the infrastructure provider does their own cheapest solution, and sticks the resulting issues on the vehicle providers and the operators.

Infrastructure and operation, in most tram networks, are the same company.
 

JonasB

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Indeed. Vehicles for pre-metro and networks more towards the light rail end of the spectrum are pretty universally double-ended. I believe Hannover has (or had) some single-ended vehicles with doors both sides, but these run in pairs coupled back to back.

There is a part of the Gothenburg tram system that was built as a premetro and still very much looks like it. But Gothenburg until recently only had single-ended trams with doors on the right. So in the premetro part of the line, the trams run on the left.

One of the premetro stations, and where the trams change from driving on the right to the left.

Hammarkullen, the most metro-like station on the network. Note the slope between the end of the platform and the exits, the station was designed to be converted to a metro station with a much higher platform.
 

Austriantrain

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Infrastructure and operation, in most tram networks, are the same company.

And mostly, the decision between single-end and double-end trams is a historic one. I know of no new single-end tram system.

In effect, the debate has been won. New systems are invariable laid out for double-ended trams.

However, if you had a single-end ystem all along, there are quite good reasons not to change it, especially as all the infrastructure is already there.

The reason why Germany, Austria and Switzerland mostly have single-ended systems is because we are slow movers, not very modern and thus didn’t close down our trams in the 1950s and 60s. With hindsight, a good decision;)
 
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DanielB

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There are many of these loops in Amsterdam, one at each end point except those on the lines to IJburg and Amstelveen which are operated by bi-directional trams. Also Rotterdam and The Hague have many loops as I believe all trams in Rotterdam are unidirectional and most in The Hague are.
Regarding Rotterdam you're right, they only have unidirectional trams. In The Hague however more and more trams have become bidirectional: all RegioCitadis trams at RandstadRail (between The Hague and Zoetermeer) are, as well as the relatively new Siemens Avenio trams. There still are routes which are operated with the old GTL stock which is unidirectional however, which obviously have loops at the end.

The remarkable thing in The Hague is however that they also have quite a few loops at routes only served by bidirectional trams:
- Route 11 has a loop both in Scheveningen Haven and at Den Haag Hollands Spoor station, in both cases there is no space for tailtracks
- Route 2 has a loop in Kraayenstein (but a tailtrack in Leidschendam)
- Route 9 also has a loop at both Vrederust and Scheveningen Noorderstrand, for the obvious reason it shares the loop in Scheveningen with route 1 (ran with unidirectional trams)
- Route 34 (peak-hour service) has a loop at its The Hague terminus, although the remainder of the tram lines it runs on was rebuilt to bidirectional operation.
- The brand new terminus at Delft University (not yet in service) has a loop, although route 19 which will eventually serve it runs with bidirectional trams (and cannot do otherwise, as its other terminus doesn't have a loop)

Several of the mentioned routes by the way have island platforms, so despite having a loop cannot be served with unidirectional trams.
 

edwin_m

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Regarding Rotterdam you're right, they only have unidirectional trams. In The Hague however more and more trams have become bidirectional: all RegioCitadis trams at RandstadRail (between The Hague and Zoetermeer) are, as well as the relatively new Siemens Avenio trams. There still are routes which are operated with the old GTL stock which is unidirectional however, which obviously have loops at the end.

The remarkable thing in The Hague is however that they also have quite a few loops at routes only served by bidirectional trams:
- Route 11 has a loop both in Scheveningen Haven and at Den Haag Hollands Spoor station, in both cases there is no space for tailtracks
- Route 2 has a loop in Kraayenstein (but a tailtrack in Leidschendam)
- Route 9 also has a loop at both Vrederust and Scheveningen Noorderstrand, for the obvious reason it shares the loop in Scheveningen with route 1 (ran with unidirectional trams)
- Route 34 (peak-hour service) has a loop at its The Hague terminus, although the remainder of the tram lines it runs on was rebuilt to bidirectional operation.
- The brand new terminus at Delft University (not yet in service) has a loop, although route 19 which will eventually serve it runs with bidirectional trams (and cannot do otherwise, as its other terminus doesn't have a loop)

Several of the mentioned routes by the way have island platforms, so despite having a loop cannot be served with unidirectional trams.
There are still sometimes good reasons for loops, as they allow more efficient turnback when services are frequent. Blackpool has several as mentioned above, but its only single-ended trams were some of the special cars for the Illuminations. And if the loop is there already there's probably no good reason to spend money taking it out!
 
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