(Trivia) Are there any uni-directional single lines?

[TheEdge]

While driving past a helpful sign on a single line section that said "trains can run in either direction on this line" I wondered to myself if there is anywhere where that isn't true?

Obviously there are countless sections of single lines as part of a whole formation that are uni-directional but are there any areas where there is an extended single line between two geographically distinct locations where you'd have to take a totally different route to go back?

Lets disregard curves and chords where its just a matter of a short (sub mile or so) reversal to get round them.

 

[61653 HTAFC]

An obvious one is the Wirral line loop under Liverpool city centre, don't know if it has signs stating that trains only run clockwise though.

 

[pdeaves]

There's all sorts of flying junctions but you have disregarded most of them. There's the new one north of Nuneaton that's a bit longer, plus a longer bit of new formation around Norton Bridge that may count.

 

[superjohn]

The Hitchin flyover line must be in with a shot. I read an article that stated it is 2km long but I don‘t know if that includes the section before it deviates from the ECML.

The area around Ripple Lane where the LTS up and down lines split around the old depot site springs to mind as well.

 

[Freightmaster]

The area around Ripple Lane where the LTS up and down lines split around the old depot site springs to mind as well.

Healey Mills has a similar layout too.




MARK

 

[Ianno87]

Terminal 4 loop on the Piccadilly line.

== Doublepost prevention - post automatically merged: 16 Nov 2020 ==

An obvious one is the Wirral line loop under Liverpool city centre, don't know if it has signs stating that trains only run clockwise though.

Problem is that, especially in a tunnel, it is very easy to get disoriented about which way the 'correct' direction actually is.

 

[trebor79]

The Hitchin flyover line must be in with a shot. I read an article that stated it is 2km long but I don‘t know if that includes the section before it deviates from the ECML.

Thread drift, but I've often wondered if any trains are still timetabled to use the ladder junction rather than the flyover, to maintain route knowledge in case the flyover isn't available for some reason? all of the points seem to still be in place, and last time I passed there the lines didn't look completely rusted, so something must pass that way.

 

[Ianno87]

Thread drift, but I've often wondered if any trains are still timetabled to use the ladder junction rather than the flyover, to maintain route knowledge in case the flyover isn't available for some reason? all of the points seem to still be in place, and last time I passed there the lines didn't look completely rusted, so something must pass that way.

Yes, it is still used from time to time; I think it's slightly quicker than the flyover if there nothing approaching on the Up to cause a conflict.

 

[pdeaves]

Thread drift, but I've often wondered if any trains are still timetabled to use the ladder junction rather than the flyover, to maintain route knowledge in case the flyover isn't available for some reason? all of the points seem to still be in place, and last time I passed there the lines didn't look completely rusted, so something must pass that way.

When we specially travelled there to 'do' the flyover the train did the old crossovers! We ended up getting extra Letchworth-Hitchin returns for a second attempt.

Other single direction bits are the various power station loops past and present.

 

[TheEdge]

There's all sorts of flying junctions but you have disregarded most of them. There's the new one north of Nuneaton that's a bit longer, plus a longer bit of new formation around Norton Bridge that may count.

I know there is lots of those but they don't really fall under what I was thinking about. Otherwise this would just become a list of flying junctions .

The Hitchin flyover line must be in with a shot. I read an article that stated it is 2km long but I don‘t know if that includes the section before it deviates from the ECML.

The area around Ripple Lane where the LTS up and down lines split around the old depot site springs to mind as well.

I'd give the Hitchin Flyover as borderline pass for this thread as it is a fairly significant deviation from the main formation.

Thread drift, but I've often wondered if any trains are still timetabled to use the ladder junction rather than the flyover, to maintain route knowledge in case the flyover isn't available for some reason? all of the points seem to still be in place, and last time I passed there the lines didn't look completely rusted, so something must pass that way.

That sort of thing doesn't really fall under route knowledge. Anyone who signed Hitchin Junction would automatically (and be expected to) know all the legitimate routes to pass through it.

 

[30907]

When we specially travelled there to 'do' the flyover the train did the old crossovers! We ended up getting extra Letchworth-Hitchin returns for a second attempt.

Other single direction bits are the various power station loops past and present.

Is the curve at Ely still unidirectional? Not sure that quite fits the OP's definition though.

 

[TheEdge]

Is the curve at Ely still unidirectional? Not sure that quite fits the OP's definition though.

It's bidirectional isn't it? I'm sure there used to be a EMT on maybe a Sunday in each direction that went over it to maintain knowledge.

 

[Ianno87]

Is the curve at Ely still unidirectional? Not sure that quite fits the OP's definition though.

It's bidirectional isn't it? I'm sure there used to be a EMT on maybe a Sunday in each direction that went over it to maintain knowledge.

Was uni-drectional from 1992, until about 2015 or so when it was made bi-directional with the West Junction crossover finally put in.

It temporarily become uni-directional again in 2017 when the Freightliner derailment took out the crossover for a while (since re-instated)...

A Sunday afternoon Norwich-Liverpool is routed that way for route knowledge retention.

 

[pdeaves]

The Sleaford avoider was unidirectional for a long time until the second track was repaired/brought back into use.

That over-mile-long curve that permits Chester-Liverpool non-Merseyrail services should surely count, though the Chester-bound direction has been reinstated now.

 

[steamybrian]

The Romney, Hythe and Dymchurch Railway have their long loop at Dungeness.

 

[sammorris]

Thread drift, but I've often wondered if any trains are still timetabled to use the ladder junction rather than the flyover, to maintain route knowledge in case the flyover isn't available for some reason? all of the points seem to still be in place, and last time I passed there the lines didn't look completely rusted, so something must pass that way.

Yes, it is. I live a few hundred yards from it, and occasionally things do go the 'other way' on the old line, usually very early or very late. I can't see anything from here but distant lights moving, but you certainly know they're doing it - it makes a screech that must be audible for miles. (Trains arriving from Cambridge did this for a while too, but presumably some improvements were made and they rarely do now).

 

[Deepgreen]

Kennington Northern line loop - edit, sorry - doesn't fit the OP's stipulations. The East Putney District line link is used very much more in one (down) direction than the other - as an ECS route to Wimbledon depot but only in times of disruption in the up direction.

 

[steamybrian]

Croydon Tramlink have a long uni-directional loop through the town centre.
East Croydon station- George Street- Church Street- Centrale- West Croydon- Wellesley Road- East Croydon

 

[swt_passenger]

...The East Putney District line link is used very much more in one (down) direction than the other - as an ECS route to Wimbledon depot but only in times of disruption in the up direction.

The normal (pre COVID) timetable did include a couple of daily up trains in passenger service however...

 

[A Challenge]

Not sure whether The Forest to Wilkinson Street on the Nottingham Trams is long enough to count, but will say that anyway

 

[paul1609]

The Chiltern main line splits in to 2 distinct single lines for over 2 miles south of Princes Risborough.

 

[Whistler40145]

The Chiltern main line splits in to 2 distinct single lines for over 2 miles south of Princes Risborough.

Is that around Saunderton?

 

[paul1609]

It's the majority of the section between Princes and Saunderton. When the line was doubled they didn't open out the existing earthworks and short tunnel but built another single line alongside.

 

[Andyjs247]

It's the majority of the section between Princes and Saunderton. When the line was doubled they didn't open out the existing earthworks and short tunnel but built another single line alongside.

Actually the down line is the original single line. The newer up line was built to be less steeply graded and passes through a cutting and short tunnel and is on a different alignment.

 

[Watershed]

It's the majority of the section between Princes and Saunderton. When the line was doubled they didn't open out the existing earthworks and short tunnel but built another single line alongside.

Actually, it was the other way around - the line had originally been built as a relatively minor branch line from High Wycombe to Thame, and so it traversed the Chiltern escarpment on a steep 1:88 gradient to avoid either extensive earthworks or a tunnel.

When the line was repurposed as the Great Central Main Line at the turn of the 20th Century, this gradient was deemed too steep for the heavy freight traffic the line would see, and so instead of doubling the line along the existing steep bank, a second, shallower alignment was built at the line's new ruling gradient of 1:176. This necessitated the earthworks and (short) tunnel the Wycombe Railway had avoided originally.

Thus the 1:88 bank is now only used by down trains and there is no signalled move in the up direction. With the tracks running on separate formations for approximately 2 miles (if defined by the points between which there is no ballast in the "six foot") this is possibly a decent contender.

 

[alangla]

If light rail is included, there’s the loop round Fleetwood town centre.

 

[fairysdad]

Heathrow Terminal 4 on the London Underground if we're including metros.

Also, and I know this is technically a flying junction, but the lines around Hinchley Wood station are quite significantly separate from each other - a quick measure on Google Maps indicates that the down is about 1km from the junction to the station, while the up is 1.25km, and a good 350-400m between the two lines with a small housing estate in the middle!

 

[L401CJF]

An obvious one is the Wirral line loop under Liverpool city centre, don't know if it has signs stating that trains only run clockwise though.

Pretty sure although its only ever used in a clockwise direction, the line is signalled both directions so can be ran anticlockwise although it never is.

Sometimes when there are works ongoing in the loop they use the inbound platform at James St as a terminus, and trains head out "backwards".

 

[najaB]

If we stretch the OP's definition, the lines into Booths/EMR/etc: trains go in, but they don't come back out.

 

[Ianno87]

Pretty sure although its only ever used in a clockwise direction, the line is signalled both directions so can be ran anticlockwise although it never is.

Sometimes when there are works ongoing in the loop they use the inbound platform at James St as a terminus, and trains head out "backwards".

No, it's only the platforms (1&2) at James St that can be turned back in - the rest of the loop is uni-directional. See https://www.opentraintimes.com/maps/signalling/wirral