Tuesday, October 29, 2019

Cross River Rail's Achilles Heel - Part 2 - Northside

BrizCommuter recently looked at capacity constraints on the Beenleigh Line that will hinder optimal use of Cross River Rail (CRR) and restrict future capacity enhancements. Whilst the constraints on the Southside are most critical in the short term, there are also similar capacity constraints on the Northside.

There are currently 4 tracks between Mayne (the large depot near Bowen Hills) and Northgate, with a track in each direction for the Mains and Suburbans. The Main tracks are used by the Caboolture, Sunshine Coast, and Redcliffe Peninsula Lines. The Suburban tracks are used by the Shorncliffe Line (with some services terminating at Northgate), Airport Line, Doomben Line, and with the Ferny Grove Line branching off at Bowen Hills.
4 Track Bottleneck
The problem is that CRR will join the Mains at Mayne, with no additional tracks added between this location and points further North. Thus the Mains North of Mayne (does that rhyme?) will be utilised by both via CRR services, and via existing CBD Line services. This is likely to be split equally, with 24tph worth of am peak Inbound/Southbound services being split into 12tph via CRR, and 12tph via existing CBD Line. The Mains North of Mayne will thus have a very poor capacity increase from the current 20tph to 24tph. This can actually be achieved alone just through new signalling (plus more trains and drivers), and doesn't actually require CRR to be constructed. Thus the lack of additional tracks on Brisbane's Northside makes for a very poor business case for CRR.

So what can be done to make better use of the $5b CRR tunnel? There is no question that to fully unlock CRR will require additional tracks on the Northside between Brisbane and Petrie (Lawnton to be precise). The most ideal solution would be to build the Trouts Road Line, which has been discussed in detail before on BrizCommuter's blog. This would ideally run in a tunnel from Roma Street (connected to CRR), surface at Everton Park, and run along the Trouts Road / North West Transportation corridor to Strathpine. A 4th track would be required between Strathpine and Lawnton. This would allow up to an additional 24tph to run to/from the Caboolture, Sunshine Coast, and Redcliffe Lines instead of a pathetic 4tph. It would speed up journey times from Brisbane to/from Caboolture and the Sunshine Coast, and also add stations to many Northern Brisbane suburbs that are currently devoid of decent public transport. Sadly, tunnel stubs to allow the Trouts Road Line to be easily connected to CRR were left out of the design, so to make this connection will require the closure of CRR for possibly a couple of months.
BrizCommuter's proposal for the Trouts Rd Line
A cheaper, but less effective version would be for the Trouts Road Line to join the Ferny Grove Line at Alderley. The tracks could be skewed around Mayne to re-route the Shorncliffe, Airport, and Doomben Lines onto the Mains. All Mains North of Mayne services would be routed via CRR. However this would have minimal journey time advantages due to the indirect nature of the inner-Ferny Grove Line, and only allow for an additional 16tph of services from Caboolture, Sunshine Coast, Redcliffe, and Ferny Grove Lines.

A final option would be to add additional tracks along the existing North Coast Line. However with the area between Mayne and Northgate already being quite built up, this would be almost impossible.

There is no question that in the current iteration, CRR is very poor value for money. It is imperative that funding is found to build the Trouts Road Line to allow for significant train service improvements from the North, and get much better value for money from the $5b spent on CRR.

Saturday, October 26, 2019

Cross River Rail's Achilles Heel - Part 1 - Beenleigh Line Constraints

Back in July, BrizCommuter wrote about the multiple existing system constraints that may affect Brisbane's Cross River Rail (CRR) achieving the proposed service pattern, and preventing future capacity increases. These were:

  • Lack of 4th track between Dutton Park (CRR portal) and Salisbury 
  • Lack of 4th track between Salisbury and Kuraby
  • Northside capacity constraints
  • Lack of tunnel stubs to allow for Trouts Road Line/North Western Transportation Corridor
  • Lack of enhanced train turnback facilities at Salisbury, Kippa-Ring, Kuraby, Manly, and Beenleigh 
  • Lack of duplication of the Cleveland Line 
  • Multiple "dangerous" Level Crossings 
  • Lack of Trains and Drivers
In this article BrizCommuter looks at one of the more concerning constraints, the lack of tracks on the Beenleigh/Gold Coast Line corridor. 

The proposed am peak service pattern shows the following expectations around the Dutton Park (Southern) Portal for CRR:
  • 18tph Inbound into CRR (12tph from Gold Coast, 6tph from Beenleigh)
  • 7tph Inbound via South Bank (7tph from Salisbury, eventually Beaudesert Line) 
  • 12tph Outbound via CRR (12tph presumably from Caboolture/Sunshine Coast)
  • 7tph (presumed) Outbound via South Bank 
There are proposed to be just three tracks (and platform faces at all stations) between Salisbury and Dutton Park. This is one less running track than the original plans for CRR where the tunnel surfaced at Yeerongpilly. In the am peak direction (Inbound) the via CRR and via South Bank services will be expected to use seperate tracks between Salisbury and Dutton Park to allow the ex-Beenleigh and ex-Gold Coast services to run express, and the ex-Salisbury/Beaudesert services to service all stations. Unfortunately, as there are only three tracks then 19tph Outbound services - formed from 12tph services via CRR, and 7tph via South Bank will have to share a single track. This will cause issues as the express services will get stuck behind the all stations trains. Only 4tph of these might be expresses heading to Beenleigh and the Gold Coast (see a later section as to why just 4tph), and the rest are likely to be slower all station services to Salisbury/Beaudesert, or empty trains heading to stabling at Clapham near Moorooka. A mixed bag of 18tph express and all stations services running along this section is likely to be a scheduling and reliability nightmare. The lack of 4th track along this section is a major Achilles Heel that will severely limit adding additional train services to the Gold Coast, Beenleigh, and Beaudesert Lines in the future. It is also concerning that some of the station designs between Dutton Park and Salisbury appear to make it difficult to add a 4th track when required. Turnback facilities at Salisbury and provision for a grade separated junction at Salisbury for when the Beaudesert Line opens also need consideration. 
Not much room for a 4th track at Dutton Park
Unfortunately, this isn't the only major capacity constraint on the Beenleigh Line corridor. You may have noticed the lack of proposed off-peak services patterns on CRR's website. Well, that is because it could be quite embarrassing for the authorities involved with CRR. There are only three tracks between Salisbury and Kuraby. This means that the express Gold Coast services can only overtake the all stations Beenleigh Line services in one direction, not both. This was the reason for the Beenleigh Line services being axed during the 2018 Commonwealth Games. Without a 4th track along this section (which based on the current timetables would ideally be in the vicinity of Altandi) then the Gold Coast and Beenleigh Lines may be limited to just 2tph each, the same as at present. This somewhat defeats the purpose of building a $5b+ tunnel! It may be possible to run a combined 6tph service by adjusting stopping patterns, or more by slowing down Gold Coast Line services, but that is far from ideal. 
The problem with 3 tracks
There are further capacity or reliability constraints between Kuraby and Beenleigh and at Beenleigh station. There are only two tracks on this section, with a passing place in the Inbound direction only at Bethania which is currently used in the am peak. Without track enhancements, this section may struggle to reliably handle any more than 8tph Gold Coast and 4tph Beenleigh Line services, compared to the proposed 12tph Gold Coast and 6tph Beenleigh Line services. Additionally the current track layout at Beenleigh has limitations, in particular with trains entering service from the sidings in the am peak. To retain the current 2 platform layout, then ideally the track layout would need to be re-arranged to place multiple sidings in-between the Gold Coast Line tracks. The multiple level crossings on the Beenleigh Line also need to be grade-separated to improve system reliability. 

So to conclude - changes required for the Beenleigh Line corridor to optimise CRR train services are as follows:
  • 4 tracks between Dutton park and Salisbury (with the enhanced station designs altered to allow this to occur)
  • 4 track sections between Salisbury and Kuraby
  • Grade separated junction at Salisbury when the Beaudesert Line opens
  • Turnback facilities at Salisbury until the Beaudesert Line opens
  • 3 track sections between Kuraby and Beenleigh
  • Track layout / stabling reconfiguration at Beenleigh
  • Grade-Separation of level crossings on the Beenleigh Line
A further article will look at the other major "Achilles Heel" for CRR - Northside constraints.