Combined CRR / Metro Tunnel

[#Metro]

[#Metro]

Basics:

* Single double deck tunnel with CRR trains and standard gauge metro vehicles together
* Initial stage of the metro would be from Wooloongabba to Herston Depot
* Metro would be able to run on to the Northern Busway and SE Busways, something that Queensland Rail trains cannot do.
* Metro portal at Wooloongabba to allow exit on to the SEB.
* Preferably automatic

Tunnel built so that QR rail component has space for potential higher speed upgrade (a byproduct of Metro being standard gauge)

Funding:

* Brisbane City Council as the metro component will solve their bus problem
* Queensland Government for the rail component
* Australian Government

Bus network reform would take place and be completed before the tunnel was constructed to provide relief to the network as a stop-gap measure.

Stations:

Stations would be shared with CRR in the combined CBD Core, as seen in other metro networks where different lines converge and run together through the CBD.

* SE Busway stations (Metro Only)
* Wooloongabba (Metro, CRR)
* CBD Albert Street (Metro, CRR)
* Roma Street (Metro, CRR)
* Northern Busway (Metro Only)

Notes:

This proposal is one that has something for all levels of gov't and avoids the very expensive possibility of having to come back later and put through a separate tunnel through the CBD again for any future metro.

There is a precedent for this. The Market Street Subway in San Francisco is built to have BART regional trains on one deck of the tunnel, and MUNI Metro light rail on another deck. https://en.wikipedia.org/wiki/Market_Street_Subway

"The Market Street Subway is a double-decker subway tunnel that carries Muni Metro and BART train traffic in San Francisco, California.[1][2] It runs under the length of Market Street between Embarcadero Station and Castro Street Station. The upper level is used by Muni Metro lines and the lower level is used by BART lines. BART does not run through the whole subway; it turns south and runs under Mission Street southwest of Civic Center Station."

Nobody has demonstrated any alternative alignment anywhere for a metro that would reach the 12 000 pphd on the SE Busway currently. The SE busway is the logical place to put a metro service.

[Gazza]

I don't think you could do a 2nd deck, bigger station boxes, depot and rolling stock for BCCs $1.5 billion budget though.

[SurfRail]

A single bore is considerably more expensive than smaller twin tubes, especially if you want both decks to carry trains.  $$$.

[#Metro]

A single bore is considerably more expensive than smaller twin tubes, especially if you want both decks to carry trains.  $$$.

Examples?

Not sure I mind how it is done, so long as it is packaged together. Perth tunnels are twin in the CBD.
Two separate borers used.

[Gazza]

Yes exactly, Perth tunnels are twin bore, and so was CRR, and in fact the NWRL is twin bore too.

This is because increasing the criss cross section of a tube grows exponentially.

Eg a 6m wide tunnel: 28.27sqm
But a 12m wide tunnel 113.1sqm

[ozbob]

True, but not the only consideration.  I think it depends a little on soil type and so forth.

Cost benefits of large-diameter bored tunnels > http://tunneltalk.com/TunnelTECH-Apr2015-Arup-large-diameter-soft-ground-bored-tunnel-review.php

[#Metro]

This is possibly how a combined option could work (concept only)

The main thing is to set it up so that future stages can be set up along the SE Busway and Nth Busway.

Depending on the setup, you could have it so that cross-platform transfer was possible. Simply walk across from CRR into the SEB or Nth Busway Metro at any combined CBD CRR/Metro stations. That possibility is a powerful reason to combine the alignments through the CBD and another mark against putting in the metro as a separate alignment.



Apologies, but I can't seem to save the image in a larger format.