Hey guys,
Since there has been a lot of talk on various topics regarding Shorncliffe, Airport line duplication, Northgate-Indooroopilly shuttle, and the fate of the Doomben line, I decided to create a thread regarding the infrastructure and operations on Sector 2 post-CRR.
Does anyone know if there will actually be much of timetable increase on sector 2 post CRR? Seems most of it will be concentrated on sector 1, especially considering they are only getting 65 QTMP’S. Also if QR really wanted to increase capacity off peak and on weekends is that realistically something that they could implement tomorrow as long as they were willing to pay for extra staff?
There definitely will be an increase in service on Sector 2 (especially northside). There is one major obstacle for the current suburban sector where GC trains have to headbutt Beenleigh trains on the tri/double track corridor from Boggo Road to Beenleigh, causing restriction on how the current suburban sector is timetabled. With the northside Sector 2 lines being paired with a functional quad-track from Corinda to Roma Street, the hurdle of ensuring express Ipswich trains don’t headbutt into all-stop Springfield trains has already been resolved. Just gotta figure out what to do with the Corinda-Darra tri-track.
Funny enough, with the incongruent planning of CRR, it has provided the additional capacity to Sector 2 instead of 1 as intended, so it would be easier for a timetable increase on Sector 2 compared to Sector 1.
Baseline: policy goal of 15 minute frequency all day on each branch, more in peak as needed for capacity reasons.
This is achievable to the Airport, to Springfield, to Rosewood (15 minutes to Wulkaraka) and (98% sure) to Shorncliffe also.
Doomben would require partial duplication (I’d suggest the Ascot side of the Hendra LX to Doomben - the platforms are already there and the remaining 6-minute single track section can be adequately timetabled around).
If trends continue, the next problem is the Westside hitting peak capacity (see the Inner City Rail Capacity Study 2008). This seems potentially addressable in the short term by running say 8tph of Corinda starters/finishers all stops sector three, while the T1 and T2 run semi-express Corinda-Indro-Toowong-Milton. (I’m not sure how you’d number the Corinda peak services, they presumably wouldn’t continue to Doomben unlike their off peak counterparts.)
I’m not sure how you’d number the Corinda peak services
Lower-case letter suffixes? (T1a etc)
About that track layout at Oxley, I have drawn a diagram that shows how the train lines could run on that corridor.
One positive about this possible arrangement is that it fully segregates the all-stops T2 trains from the express T1 and T3 trains on the quad-track from Corinda to Roma Street.
However, platform 3 at Darra station remains unused. The platform can only be used by upward T1 and T3 trains since it only leads to the up track to Ipswich and Rosewood, but up T1 and T3 trains would have to share the same track as the down T2, causing conflict on the middle track at Oxley.
As a result, the upward express and all-stop trains cannot be segregated on the tri-track corridor while the downward express and all-stops trains remain fully segregated, causing an imbalance in capacity for each direction.
And this is why we need that little piece of track at Oxley to be electrified once and for all…
It’s going to need a little bit more than electrification of the fourth track since that track is completely isolated from the rest of the tracks (i.e. there are no switches). Furthermore, the track layout between Corinda and Oxley is a complete dog’s breakfast.
