Ridiculous dwell locations, especially at Roma St

[somebody]

Can we please abolish timetabled dwells at Roma St for train services in both directions.  Outbound trains have just had their recovery times, and inbound trains are about to have it, so why wait at Roma St?  All it does is inconvenience everyone South and West of Central.

The most glaring example of this in the bus system is at the Cultural Centre.  For inbound buses that have just joined the busway system and may be about to terminate at QSBS, it's simply absurd, and could cause completely unnecesary congestion.

[stephenk]

I think one of the reasons for extended dwells at Roma St and Central is because the services are timetabled to just use one track in each direction between Bowen Hills and Roma Street if required at weekends. Taking the full dwell time at Central would not be possible in platforms 5 and 6 as the following train would catch up, thus a couple of minutes dwell is also needed at Roma Street.

One excessive dwell time is that the pm expresses on the Ferny Grove often have to wait for 3 mins at Keperra to enter the single track section. How about making the train less express, serve Enoggera and Gaythorne again, and reduce the dwell at Keperra?

[somebody]

I think one of the reasons for extended dwells at Roma St and Central is because the services are timetabled to just use one track in each direction between Bowen Hills and Roma Street if required at weekends.

That's a pretty bad reason.  Especially on weekdays.

Taking the full dwell time at Central would not be possible in platforms 5 and 6 as the following train would catch up, thus a couple of minutes dwell is also needed at Roma Street.

Is that off peak?  Trains are only running through there every 15 minutes, so I don't think so.

One excessive dwell time is that the pm expresses on the Ferny Grove often have to wait for 3 mins at Keperra to enter the single track section. How about making the train less express, serve Enoggera and Gaythorne again, and reduce the dwell at Keperra?

Is that the 4:49 ex Central which arrives at Ferny Grove at 5:18?  The previous trains has arrived at 5:08pm and must return empty as there is no service.  Given that it's returning empty, I'd think you could do so in 7 minutes, but it would be tight.  Of course, why not do the obvious thing and have the express leave later?  I know you HATE express services, and I do agree that they are marginal on this line, but they have their good points.

[stephenk]

Taking the full dwell time at Central would not be possible in platforms 5 and 6 as the following train would catch up, thus a couple of minutes dwell is also needed at Roma Street.

Is that off peak?  Trains are only running through there every 15 minutes, so I don't think so.

There are 10tph at weekends:-
2tph Caboolture/Ipswich
2tph South Brisbane/Shorncliffe
2tph Cleveland/Bowen Hills or Doomben
2tph Gold Coast/Airport
2tph Beenleigh/Ferny Grove
10tph = 6mins frequency. If all services are limited to platforms 5&6, then even if the services are evenly spaced, this gives only 4 mins max at Central if you allow 2 mins for platform re-occupation.

As the weekday and weekend off-peak timetables are similar (so as to not confuse passengers), the same dwell times have to be applied to weekday off-peak as well as weekend off-peak.

[somebody]

Well, I still think that's a bad reason.

[mufreight]

A lot of the dwell times at Roma Street for trains going south or west should be to enable connnections with trains coming from the south or west.
No doubt the coordination could be improved but such improvements are beyond the mental capabilities of the transport planners at Translink.

[STB]

The extra minute dwell time at Roma Street was done to remove a minute of dwell time at Central, so there would be no dwelling longer than 3mins, ie: to spread the dwell time, and to attend to pax on and pax off at Roma Street.  It has nothing to do with connections.

[somebody]

The extra minute dwell time at Roma Street was done to remove a minute of dwell time at Central, so there would be no dwelling longer than 3mins, ie: to spread the dwell time, and to attend to pax on and pax off at Roma Street.  It has nothing to do with connections.

That's a worse reason!  Shouldn't they be adjusting the timetable then?

A lot of the dwell times at Roma Street for trains going south or west should be to enable connnections with trains coming from the south or west.
No doubt the coordination could be improved but such improvements are beyond the mental capabilities of the transport planners at Translink.

But was it any different in the pre-Translink days?

[Derwan]

That's a worse reason!  Shouldn't they be adjusting the timetable then?

Your whole point was, "Outbound trains have just had their recovery times, and inbound trains are about to have it, so why wait at Roma St?"

The answer is that the "recovery time" has been spread between Central and Roma St.  That is, the dwell time at Roma St is part of the recovery time. 

[somebody]

Your whole point was, "Outbound trains have just had their recovery times, and inbound trains are about to have it, so why wait at Roma St?"

The answer is that the "recovery time" has been spread between Central and Roma St.  That is, the dwell time at Roma St is part of the recovery time. 

I did also add that it inconveniences people South/West of Central.  So it wasn't my whole point.  Looked at that way, I say we should abolish that part of the recovery time then.  The dwells aren't exactly short at any point on the network, and yet reliability isn't particularly good.  CityRail might run from Campbelltown to the city and back to Glenfield via Granville with no dwell and then do a 9 minute turn which includes the entire recovery time for the route.  That's probably about the same distance as Ipswich-Caboolture, and maybe a bit more.  Now, CityRail have slowed down the whole timetable which is a much worse option, but they used to do exceedingly short recovery times.  Perhaps they aren't the best example to follow though.

[somebody]

Some other places where this applies are:
Ferny Grove
Varsity Lakes
Domestic Airport Terminal
International Airport Terminal, outbound (4 mins to get to Domestic is excessive, why not trim fat off of the timetable)
Cleveland
Caboolture

The Varsity Lakes/Airport one drives me crazy, because it applies at both ends of the run, and they could easily apply logic and shave 30mins off of the dwells between those two locations.  I'm not sure what they are thinking really.  The single tracks shouldn't prevent this.

Are the timetablers incompetent?

[Emmie]

I think the international and domestic airport dwell times are longer because of the extra time passengers may need to load baggage.  Unfortunately, as these trains run nearly empty most of the time, they probably DON'T need long dwell times at present - but it's pretty standard practice for airport railways in other cities to allow extra loading time.

[somebody]

I think the international and domestic airport dwell times are longer because of the extra time passengers may need to load baggage.  Unfortunately, as these trains run nearly empty most of the time, they probably DON'T need long dwell times at present - but it's pretty standard practice for airport railways in other cities to allow extra loading time.

It's not noticeable at SYD domestic.  Perhaps at other locations it is.

[Emmie]

SYD domestic is unusual in that it is in the middle of a suburban rail line.  Try Frankfurt or London Heathrow, and the dwell times are longer.

[stephenk]

Are the timetablers incompetent?

Not in this case. Long terminus dwells can considerably improve reliability. The running time of a service, it's frequency, and having to fit the service around other lines (critical in the case of the Gold Coast Line as it runs express) all affect the available options for terminus dwell time. The schedulers thus often have little choice of terminus dwell time when all the parts of the jigsaw are put together!

As an example, at Ferny Grove a train can arrive 19 mins late, and still depart on time. Surely that's a good thing?

[somebody]

Are the timetablers incompetent?

Not in this case. Long terminus dwells can considerably improve reliability. The running time of a service, it's frequency, and having to fit the service around other lines (critical in the case of the Gold Coast Line as it runs express) all affect the available options for terminus dwell time. The schedulers thus often have little choice of terminus dwell time when all the parts of the jigsaw are put together!

As an example, at Ferny Grove a train can arrive 19 mins late, and still depart on time. Surely that's a good thing?

Maybe, but don't you think it's a little excessive?  At the Beenleigh end the turnaround is 25mins.  I know there's an off platform turnback here, which takes time, but I'd think they could still have adequate make up time and trim the dwells by the half hour required.  Perhaps that's a bad example, it does depend on how long it takes to swap platforms at Beenleigh.

Cleveland has a 32 minute dwell, so if the outbound service is delayed by more than 2 minutes, it delays the inbound service too.  Seems odd.

I've looked at the Airport one in finer detail and it seems pretty difficult to avoid the dodgy cross at International with the constraints of the two single track sections.  But you could cut a half hour out.  And the dodgy cross applies now anyway.

[stephenk]

Are the timetablers incompetent?

Not in this case. Long terminus dwells can considerably improve reliability. The running time of a service, it's frequency, and having to fit the service around other lines (critical in the case of the Gold Coast Line as it runs express) all affect the available options for terminus dwell time. The schedulers thus often have little choice of terminus dwell time when all the parts of the jigsaw are put together!

As an example, at Ferny Grove a train can arrive 19 mins late, and still depart on time. Surely that's a good thing?

Maybe, but don't you think it's a little excessive?  At the Beenleigh end the turnaround is 25mins.  I know there's an off platform turnback here, which takes time, but I'd think they could still have adequate make up time and trim the dwells by the half hour required.  Perhaps that's a bad example, it does depend on how long it takes to swap platforms at Beenleigh.

Cleveland has a 32 minute dwell, so if the outbound service is delayed by more than 2 minutes, it delays the inbound service too.  Seems odd.

I've looked at the Airport one in finer detail and it seems pretty difficult to avoid the dodgy cross at International with the constraints of the two single track sections.  But you could cut a half hour out.  And the dodgy cross applies now anyway.

If you shortened Beenleigh's dwell time then you will affect the dwell times at Ferny Grove, Varsity Lakes, Airport, and possibly other termini as well. It all has to fit in like a jigsaw, otherwise you will end up with Gold Coast trains catching up with Beenleigh Trains etc etc.

[somebody]

True, but you could fix Airport/GC & probably Cleveland and slave Beenleigh/FG to them at whatever dwell times work out.  Two out of three ain't bad, and even one is better than none.

[somebody]

Further to my last post, I figure an 11 minute dwell at Domestic, a 19 minute dwell at Varsity Lakes, a 10 minute dwell at Ferny Grove and a 12 minute dwell at Beenleigh would work out based on current running times, except for 3 minutes (not 5) Varsity Lakes-Robina in both directions, and 2 minutes International-Domestic northbound.  But going back to the currently timetabled times makes little difference here.

The Cleveland line trains could just slot in anywhere that inner city capacity allows.

I suppose that is much tighter than present for the Ferny Grove-Beenleigh trains.  Leaves only a small amount of time for a loo stop and reversing the Beenleigh train in the siding.

The main constraint is the Airport & Coomera-Helensvale single track.  The latter could be duplicated much more cheaply, so perhaps that should be done as a bit more of a priority.  This would also allow a modest amount of recovery time at the Airport, which is not possible now.

If you want proof I can post my timings.

[stephenk]

Further to my last post, I figure an 11 minute dwell at Domestic, a 19 minute dwell at Varsity Lakes, a 10 minute dwell at Ferny Grove and a 12 minute dwell at Beenleigh would work out based on current running times, except for 3 minutes (not 5) Varsity Lakes-Robina in both directions, and 2 minutes International-Domestic northbound.  But going back to the currently timetabled times makes little difference here.

At 30 min frequencies, I doubt the above terminus dwell times would allow for a robust reliable operation.

The main constraint is the Airport & Coomera-Helensvale single track.  The latter could be duplicated much more cheaply, so perhaps that should be done as a bit more of a priority. 

The Coomera to Helensvale section requires a long river crossing. This is actually relatively expensive to build!

[somebody]

The Coomera to Helensvale section requires a long river crossing. This is actually relatively expensive to build!

I'd still expect it to be a fair bit cheaper than duplicating the viaduct at the airport though.

Regarding Beenleigh/FG dwells, I'm not sure.  I presume that's the part where you have a problem, as I think 19 minutes at Varsity Lakes would be more than adequate.  It would be really nice if there was a third platform at Beenleigh and you didn't have to reverse in a siding.

My posted dwells would also only work out at FG so long as the frequency didn't up to 15 minutes before they put in the FG-Keperra duplication.  So I suppose that's something we shouldn't be suggesting.  Make FG 15 minute frequency and you could do it reasonably easily with more slack dwells.

[stephenk]

The Coomera to Helensvale section requires a long river crossing. This is actually relatively expensive to build!

I'd still expect it to be a fair bit cheaper than duplicating the viaduct at the airport though.

Regarding Beenleigh/FG dwells, I'm not sure.  I presume that's the part where you have a problem, as I think 19 minutes at Varsity Lakes would be more than adequate.  It would be really nice if there was a third platform at Beenleigh and you didn't have to reverse in a siding.

There was a Gold Coast train running 22mins late this am. If it only had 19mins dwell, it would depart Varsity Lakes 7-11mins late. This in turn would either have to delay the following ex-Beenleigh Line train (which would have a delayed departure from Beenleigh), or further delay itself (as it would run behind the ex-Beenleigh Line train.

If and when the Beenleigh Line gets a 15mins frequency to Kuraby, delays will be even more critical.

I cannot see much advantage of a 3rd platform over a reversing siding - it would not be worth the construction costs!

[somebody]

The Coomera to Helensvale section requires a long river crossing. This is actually relatively expensive to build!

I'd still expect it to be a fair bit cheaper than duplicating the viaduct at the airport though.

Regarding Beenleigh/FG dwells, I'm not sure.  I presume that's the part where you have a problem, as I think 19 minutes at Varsity Lakes would be more than adequate.  It would be really nice if there was a third platform at Beenleigh and you didn't have to reverse in a siding.

There was a Gold Coast train running 22mins late this am. If it only had 19mins dwell, it would depart Varsity Lakes 7-11mins late. This in turn would either have to delay the following ex-Beenleigh Line train (which would have a delayed departure from Beenleigh), or further delay itself (as it would run behind the ex-Beenleigh Line train.

If and when the Beenleigh Line gets a 15mins frequency to Kuraby, delays will be even more critical.

I cannot see much advantage of a 3rd platform over a reversing siding - it would not be worth the construction costs!

One would hope such occurances are fairly isolated.  And if it had been a northbound GC train, the following southbound train would have been delayed by 22 minutes. (Unless that's enough to get out of the single track first)

Don't you think there is a limit to how much recovery time is appropriate?  Otherwise we'd be having 25 minute dwells everywhere possible.

If Kuraby trains start running, reliability is likely to be worse than present due to the tight nature of the timetable.

You can't do much worse than the Airport or Cleveland, the latter has: 32 minute dwell, 2 minutes of recovery time.  I suppose if the outbound train is really late, the inbound train could enter the single track first.

[somebody]

I've noticed in the journey planner that the northbound Ipswich-Caboolture services on Sunday are now adding dwells at Corinda and Bowen Hills, not just Roma St.  On the same overall timings as previously, but still, isn't it annoying?  Probably there was always the dwells, it's just that it was hidden.
Link: http://jp.translink.com.au/TransLinkTripTimetable.asp?Origin=CORINDA+RAILWAY+STATION&Destination=BOWEN+HILLS+RAILWAY+STATION&Date=29/8/2010&TripKey=264707&DepartTime=4.43pm

[Derwan]

I've noticed in the journey planner that the northbound Ipswich-Caboolture services on Sunday are now adding dwells at Corinda and Bowen Hills

Dwell times were added at Bowen Hills a while ago.  Not sure about Corinda though.

The dwell times are required at Bowen Hills for crew changes.

[STB]

You can't do much worse than the Airport or Cleveland, the latter has: 32 minute dwell, 2 minutes of recovery time.  I suppose if the outbound train is really late, the inbound train could enter the single track first.

That's exactly what happens.  The Cleveland line is unique in the sense that a train can run up to 20mins late and still depart on time when it does it's turnback.  In this circumstance the cross usually occurs at Wellington Point.