Coomera-Helensvale duplication

[somebody]

Went searching on the internet for a price estimate for this project, and found this: http://www1.fidic.org/conference/2007/talks/tue/sol1/walsh.pdf
Page 7 clearly shows $43m for this project, with an anticipated start in 2008.

I think for this sort of money, they should just get on with doing it, and then no longer have to consider the constraint of the single track in timetabling.

[ozbob]

Interesting, thanks for the post.

Here is the line diagram for that section.



From http://www.qrnetwork.com.au/Networks/South-East-Queensland/Beenleigh-Gold-Coast-line.aspx

[beauyboy]

I find it more interesting the projects that are spose to be underway already.

Donald

[stephenk]

Is this project required? Yes.
Is this project the most urgently required rail infrastructure in SE Queensland? Probably not.
Discuss 

[somebody]

Is this project required? Yes.
Is this project the most urgently required rail infrastructure in SE Queensland? Probably not.
Discuss 

CRR is the most important project, but it's bigger bucks for bigger bang.  You'd probably think that Ferny Grove-Keperra duplication is more important or more bang for buck.  I'm not convinced, Coomera-HV causes huge trouble for timetabling, in particular the way it combines with the Airport single track.  FG-K means it can't be done the way you would like, and a bit of an excess dwell at FG.

[Jon Bryant]

I want it all...and I want it now!!!!!

[somebody]

Discuss 

I was very interested to hear your rebuttal and how Ferny Grove-Keperra duplication is more urgent than this project.

[stephenk]

Discuss 

I was very interested to hear your rebuttal and how Ferny Grove-Keperra duplication is more urgent than this project.

Sorry, I've been a bit busy lately 

Well if we look at real overcrowding figures (i.e trains that are nearing full capacity, rather than a couple of people having to stand for more than 20mins), then the Gold Coast Line would be well down the list. Ipswich, Caboolture, Beenleigh, Ferny Grove Line, Cleveland, and even the Shorncliffe Line all have services that are near capacity. Shouldn't these lines have capacity enhancements before the Gold Coast? There are serious capacity constraints on branches that affect half-decent timetabling, which as a result contributes to overcrowding. Whilst the Coomera to Helensvale single track section is one of these, so is Ferny Grove to Keperra, 3rd platform at Manly, Cleveland Line duplications, 4th platform Kuraby, 4th track Fairfield to Banoon, stabling in various locations, etc, etc. Many of these infrastructure constraints affect multiple lines, some more than others. This is not forgetting the requirement for more trains which is also $$$ spending that has to be weighed up against infrastructure spending.

So as I mentioned above. Is it required, yes. Is it highest priority, probably not (unless you happen to be one of the few people who have to stand on the Gold Coast Line).

[somebody]

I would argue that the current timetable has exceedingly long dwells at Beenleigh, Ferny Grove, Domestic Airport and Varsity Lakes.  That means that at the end of every FG-B & VL-D run the crew must wait an additional 15 minutes on average on what they could be relatively easily doing if this constraint was addressed.  So, it's not really needed for capacity constraints, but to make timetabling much easier.  Perhaps the sums work out that the costs of doing this project are more than the savings.  Just done some calculations, and the way I figure it, they need to have a crew cost of just over $70/hour/person for this project to pay for itself in terms of the crew's time.

So, then yes. I guess I have to concede that this project is not the biggest priority.  The priority is to actually run more services rather than fix any infrastructure constraint, and it C-H single track is here to stay for some time, then that makes the incremental cost of a greater off peak Ferny Grove service pretty marginal.

[Derwan]

I live on the Shorncliffe line so I think the Sandgate-Shorncliffe duplication should take priority!   

[somebody]

I live on the Shorncliffe line so I think the Sandgate-Shorncliffe duplication should take priority!   

Can't they run 6tph without it?

Not sure if there is any other place on the line they can use as a turnback.

[stephenk]

Going back to Somebody's Ferny Grove duplication vs Coomera to Helensvale duplication discussion:

Coomera to Helensvale requires 12 mins for opposing trains to run through that section. The current am peak frequency is 15-16 mins in peak direction, and 25-36mins in counter-peak direction. Thus there thus some spare capacity through this section, including space for another counter peak service which probably cannot run due to lack of infrastructure between Brisbane and Beenleigh. There is at the minimum, a 3 min operating margin for trains passing at Helensvale in the am peak.

Keperra to Ferny Grove requires 9 mins for opposing trains to run through that section. The current am peak frequency contains 3 departures 10mins apart from each other, with inbound to Ferny Grove services (some empty) at similar frequencies. This is 1 min operating margin!

As you can see, it is pretty obvious which infrastructure requirement is required first. It is thus no surprise that planning work is well under way for Keperra to Ferny Grove. However, I find it very concerning that there is little mention in SEQIPP of when the Coomera to Helensvale duplication will occur, and SEQIPP rail seems to currently have it opening between 2016 and 2026! Once the triplication from Kuraby to Loganlea allows for further peak capacity increase on the Gold Coast Line, then I would think that duplicating Coomera to Helensvale will then be essential. 

[Derwan]

Can't they run 6tph without it?

I'm not sure what the actual limitation is.  I think the shortest gap between timetabled services at the moment is 14 minutes.  There is a single platform at Shorncliffe so a train has to get between Sandgate and Shorncliffe, switch ends and get back to Sandgate before the next service can go through. 

Not sure if there is any other place on the line they can use as a turnback.

There isn't anywhere at the moment.  Even if you were to use one of the main platforms, there are no crossovers between Northgate and Sandgate.  If you were going to spend money on infrastructure on this line, it'd have to be the duplication and Shorncliffe Station upgrade.

That said, my comment was in jest, and other projects certainly take priority at this stage.

[somebody]

That said, my comment was in jest, and other projects certainly take priority at this stage.

I took it as somewhat in jest, partly serious.

In fact, any way I turn things, I can't see that any proposed rail infrastructure project is more important than increases and improvements in services to be run on existing or future infrastructure.

For the Shorncliffe line, a double ended train north of Sandgate should allow 8tph or greater.  Besides margin, it's a 4min run.

Keperra to Ferny Grove requires 9 mins for opposing trains to run through that section. The current am peak frequency contains 3 departures 10mins apart from each other, with inbound to Ferny Grove services (some empty) at similar frequencies. This is 1 min operating margin!

I would blame the timetabling for that, really.

[stephenk]

Keperra to Ferny Grove requires 9 mins for opposing trains to run through that section. The current am peak frequency contains 3 departures 10mins apart from each other, with inbound to Ferny Grove services (some empty) at similar frequencies. This is 1 min operating margin!

I would blame the timetabling for that, really.

Well the alternative to running trains to Ferny Grove at 10mins frequency, is to turn more trains at Mitchelton, which also has operational issues due to lack of 3rd platform. Again, another reason why duplication Keperra to Ferny Grove is in the latter stages of planning.

[somebody]

Well the alternative to running trains to Ferny Grove at 10mins frequency, is to turn more trains at Mitchelton, which also has operational issues due to lack of 3rd platform. Again, another reason why duplication Keperra to Ferny Grove is in the latter stages of planning.

Yes.  When you say operational issues with turning at Mitchelton, I take it you mean the need to use the wrong direction platform for Mitchelton starters?

[stephenk]

Well the alternative to running trains to Ferny Grove at 10mins frequency, is to turn more trains at Mitchelton, which also has operational issues due to lack of 3rd platform. Again, another reason why duplication Keperra to Ferny Grove is in the latter stages of planning.

Yes.  When you say operational issues with turning at Mitchelton, I take it you mean the need to use the wrong direction platform for Mitchelton starters?

They can reverse in either track, and Ferny Grove bound services can run through either platform, but ex-Ferny Grove services can only use the City bound platform. However, the time in which a track is blocked by a reversing train further adds to timetabling constraints and decreases operating margins.

[#Metro]

I want it all...and I want it now!!!!!

Is it really worth building single track and then going back at some time in the future and duplicating it?