Rosangela Tsuruda is Customer Director responsible for relations with São Paulo’s two urban railways: metro operator CMSP and suburban railway CPTM. She has worked forAlstom Transport for the past 18 years.
Fernando Cirillo is Project Director of CMSP lines 1, 2 & 3 Modernisation at Alstom. He began his career working on the signalling for São Paulo Line 3 when it was being built in the late 1970s. He subsequently joined Alstom, and after eight years in France he returned as bid manager for the resignalling tender and now project director for the work.
By far the busiest metro in South America, the network in São Paulo is currently handling around 3·5 million passengers a day on a network of just 61 route-km. Despite growing levels of overcrowding, traffic is continuing to increase, but some respite is in prospect for the city’s long-suffering travellers.
According to Rosangela Tsuruda, Alstom Transport’s Customer Director, the São Paulo state government has announced ‘a huge investment plan to modernise and increase the capacity of the metro network by 2010, with a total value close to R$20bn’. Intended to deliver a significant increase in capacity on the three broad-gauge lines serving the city centre, the programme includes new and refurbished trains, a line extension, resignalling and ultimately full automation.
The first of 33 extra trains for lines 1, 2 and 3 was expected to arrive by the end of 2008, and preliminary works began in August for resignalling all three routes with communications-based train control. The introduction of moving-block signalling from mid-2011 is expected to cut peak-hour headways to as little as 80 sec, boosting train throughput by as much as 20% on some sections of the network.
Last year the state government awarded a €280m contract to Alstom for the resignalling and installation of a new voice and data communications network. It is the company’s largest-ever metro signalling contract, and follows a 2007 deal to supply 96 cars which will form 16 additional six-car trainsets.
Three varied routes
Although the three lines are connected and fully compatible, they are different in many respects. Line 1 is the oldest, dating from 1974. Now running from Tucuruvi in the north to Jabaquara in the south, it is 20 km long with 23 stations. The 23 km east-west Line 3 between Barra Funda and Itaquera, which has 18 stations, followed in 1979, and is now the metro’s busiest route. The shorter Line 2 opened in stages between 1991 and 2007, and is currently 9·6 km long with 11 stations, linking Vila Madalena with Alto de Ipiranga. A further 4 km extension of this line to Vila Prudente with three stations is currently under construction and due for completion by the middle of 2010.
All three lines are equipped with a very early form of automatic train control, based on coded track circuits, as used on London’s Victoria Line from 1968 onwards. This was adopted for Line 1 in the early 1970s and is now technically obsolete. Whereas Line 1 uses relay interlockings, Line 3 has a mix of relays and early computer-based interlockings developed locally, and Line 2 is equipped with CBI throughout. All of these interlockings are to be replaced, although the recently-modernised control centre at Rua Vergueiro will be retained. In total, the contract covers more than 57 km of double-track route, or approximately 115 track-km.
Tsuruda explains that the existing signalling allows the trains to be used interoperably between the three lines if necessary. Although this does not happen at present, metro operator CMSP wants to retain the same flexibility in case of emergencies in the future, ‘so it was an intrinsic requirement of the resignalling contract that this ability should be retained’.
Urbalis Evolution
Alstom is supplying lineside and on-train equipment for both the CBTC and a new voice/data radio network. Alstom’s Project Manager Fernando Cirillo reports that following the signing in July (RG 8.08 p480), the contract officially came into force on August 14.
The company is supplying its Urbalis Evolution equipment, which is its latest generation of CBTC for metro lines. It is an enhanced version of the equipment fitted to Singapore’s North East Line in the late 1990s, and is essentially the same as that supplied to Beijing in 2007-08 for the resignalling of Line 2 and construction of the ?automated rail link to the Chinese capital’s international airport.
Whereas Singapore uses a wave-guide throughout to ensure transmission of the radio signals, the Chinese opted to use a waveguide in the tunnel sections and free propagation of the radio signals in the station areas. São Paulo has gone one step further with free propagation throughout. The radios will be the same as those provided in Beijing, with a dedicated 5·2 GHz network using the 802.11a internet prototcol to carry the signalling and train control data. Cirillo says that the high level of redundancy provided is already giving very good performance, with Singapore and Beijing achieving a mean time between failures of around 100 000 h per unit.
A critical element of the programme is the need to ensure the reliability of the free-propagation radio signal in the tunnels, and to design the lineside transmitter stations to ensure adequate coverage. Cirillo says work will be starting ‘very, very soon’ to assess the radio coverage and install the equipment in order to conduct shadow testing during full service. This will allow Alstom to measure the effect of trains running in the tunnels, and check for interference or loss of coverage. ‘So when CBTC installation starts we will already be sure that the radio network is working properly’, he adds.
Because Urbalis is a centralised system using object controllers at the stations, Cirillo explains that the new equipment at each location will be much smaller than the existing interlockings. It can therefore be accommodated in the present equipment rooms, avoiding the need for any major station rebuilding works.
No modifications will be needed at the control centre, except for a new interface between the recently-installed workstations and the CBTC and radio communications networks.
At present train location is detected by the track circuits, which will be removed once the old signalling has been decommissioned. The moving-block CBTC relies on the reports from on-board equipment for accurate train positioning. These reports are based on odometers which are reset at regular intervals using fixed balises in the track. As a back-up for block occupancy detection, the three lines will also be fitted with axle-counters throughout.
Whereas the existing fixed-block signalling was designed for 90 sec headways, with a standard 30 sec station dwell time, Cirillo says that Line 3 is currently operating on average headways of 101 sec at peak times, with 109 sec on Line 1 and 149 sec on Line 2. Dwell times can be as little as 10 to 15 sec at some stations, he reports.
Thanks to the ability of the moving block signalling to let approaching trains ‘close up’ behind a stationary or departing train at each station, the Alstom CBTC installation has been designed for 75 sec headways. In regular operation, CMSP expects to run at 85 sec on Line 1 and between 80 and 83 sec intervals on Line 3.
As part of the signalling package, Alstom is also supplying an independent radio network for other voice and data communications on the three lines. This is being designed to allow for both fixed and mobile coverage.
Phasing is everything
With the metro handling record levels of traffic, CMSP’s intention is to maintain the current level of service throughout the project. Both Tsuruda and Cirillo are adamant that the resignalling can be done with no interruption to regular operations. Key to this lies with the Line 2 extension and its new trains, which will provide both a test track and enough rolling stock to cover trains taken out of service for retrofitting.
The Line 2 extension will be equipped with CBTC from the outset, both to pilot the installation techniques and to provide a commissioning section for testing the converted rolling stock. On the remainder of the lines, the CBTC is to be installed in parallel with existing signalling, which will remain in operation to the point where the whole service is cut over to the new signalling.
There will be no interfaces between the two signalling systems, so Alstom will only be able to test the new equipment on the running lines during the overnight non-traffic hours. Cirillo says works will be undertaken in parallel on all three routes, with the switchover to CBTC to take place simultaneously once the retrofitting of the train fleet has been completed.
One complication is the requirement to open part of the Line 2 extension as far as the first intermediate station at Sacomã by the first quarter of 2010. The remainder of the Line 2 extension will remain available to the project team until the conversion is complete, opening with the final switch-over.
Cirillo says the target is to complete all of the lineside and on-board installation work by the end of 2010, allowing six months for testing and final commissioning before the three lines are cut over in mid-2011.
On-board equipment will be installed on 142 trainsets in total - the 109 currently in operation and the 33 additional trains. Although the new cars being built by Alstom had been ordered before the resignalling contract was placed, Cirillo says it should be fairly straightforward to fit CBTC to them, as space can be left for the onboard equipment during manufacture. With deliveries contracted to run from the end of 2008 to the end of 2009, most units will have to be delivered without the CBTC and brought back to the depot for retrofitting, although Cirillo hopes that it might be possible to equip the last few trains before delivery.
The extra trains are intended to boost capacity on all three lines, making use of the additional paths provided by the moving-block signalling. The 16 Alstom-built units are destined for Line 2, where they will more than double the current fleet of 11 sets to permit more intensive services and work the extension. Another 17 sets are being supplied by CAF, of which seven will go to Line 1, which currently has 51, and the final 10 to Line 3 which has only 47 at present.
Whilst CMSP would have liked to replace the 30-year-old trains on Line 1, the state has decided to undertake a major refurbishment which will give them another 15 to 20 years in service. Tsuruda says tenders are to be called shortly for the refurbishment programme, which will also include replacement of the chopper controls and DC traction motors by three-phase AC drives.
The aim is that this work will be done in parallel with installation of the on-board train control equipment, with each train only being taken out of service once. Cirillo admits that this adds a further complication to the resignalling project with the need to synchronise the development and delivery of all the different subsystems.
Technology transfer
The resignalling contract is being managed by Alstom’s existing business unit in São Paulo. This has already developed a strong expertise in metro and main line signalling, gained from supporting the city’s metro over more than 30 years. The unit acts as a local centre-of-excellence for the whole of the South American market, and Cirillo points out that it is currently active in both Chile and Argentina.
The core CBTC technology is new to Brazil, however, and the expertise will come from Alstom’s French signalling unit, through a form of internal technology transfer. Cirillo welcomes the fact that this step will enhance the Brazilian company’s capabilities to win similar contracts elsewhere in its region, where there is not a lot of expertise in automatic train control systems.
Some equipment will be sourced from other companies in the region, including the mobile radios and elements of the communications package. Cirillo points out that Alstom has been working with local subcontractors for many years, and has regular contact with a lot of qualified firms, who are likely to provide much of the resources needed for the actual installation work.
First steps towards automation
Although at this stage São Paulo is only replacing one form of attended ATO by another, Tsuruda confirms that the longer-term intention is to introduce fully-automatic operation on all three lines. She points out that other works will be necessary before UTO can be implemented, including the installation of platform screen doors at each station and changes to the metro’s operating rules.
As part of its contract, Alstom is providing platform screen doors for five of the six termini on the three lines. This will enable CMSP to introduce fully-automatic train reversal at these stations while the train attendant is changing ends. No screens are being fitted at the southern end of Line 2, because of the phasing of the extension works.
Completion of the resignalling will bring immediate benefits for the metro in terms of additional capacity and the reduced headways that it will make possible.
Although there is a stated intention to introduce driverless operation, the timing of this step is clearly a political decision for the state government. It will also depend on the progress of negotiations between the metro operator and its employees, and it is not clear at this stage whether CMSP envisages redeploying some of its on-train staff into other customer-facing roles. Other metros moving to fully-automated operation, such as Nürnberg and Barcelona, have reached agreement to redeploy their redundant drivers as roving attendants to provide enhanced information and security services on trains and stations.