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The automation of Paris subway line 1 contributes to on-going modernisation

Posted: 25 April 2012 | Gérald Churchill, Director of line 1 Automation Project, RATP | No comments yet

The Paris subway was built between 1900 and 1935. Its Operational Control Centre (OCC), Automatic Train Operation (ATO), controlled manual driving mode and new generations of rolling stock were commissioned between 1955 and 1990. The opening of line 14 (Météor) in 1998 initiated the transition between this first wave of modernisation and the second wave programmed over the period between 2005 and 2020.

The foundations of the new modernisation programme were defined in April 2002. They were based on new technologies, equipment modularity and interchangeability and factored in the lessons learnt from the line 14 operation. Within this framework the automation of an existing line was considered. However, although the creation of an entirely automatic under – ground line did not present a particular challenge, no network had ever launched a conversion project without traffic interruption.

The choice of an automatic line depends on the benefit brought by integral automation of train movements. The three main advantages, which are universally recognised, are:

Adaptability and the potential tailoring of the offer
Increase in commercial speed
Traffic reliability improvement.

The Paris subway was built between 1900 and 1935. Its Operational Control Centre (OCC), Automatic Train Operation (ATO), controlled manual driving mode and new generations of rolling stock were commissioned between 1955 and 1990. The opening of line 14 (Météor) in 1998 initiated the transition between this first wave of modernisation and the second wave programmed over the period between 2005 and 2020. The foundations of the new modernisation programme were defined in April 2002. They were based on new technologies, equipment modularity and interchangeability and factored in the lessons learnt from the line 14 operation. Within this framework the automation of an existing line was considered. However, although the creation of an entirely automatic under - ground line did not present a particular challenge, no network had ever launched a conversion project without traffic interruption. The choice of an automatic line depends on the benefit brought by integral automation of train movements. The three main advantages, which are universally recognised, are: Adaptability and the potential tailoring of the offer Increase in commercial speed Traffic reliability improvement.

The Paris subway was built between 1900 and 1935. Its Operational Control Centre (OCC), Automatic Train Operation (ATO), controlled manual driving mode and new generations of rolling stock were commissioned between 1955 and 1990. The opening of line 14 (Météor) in 1998 initiated the transition between this first wave of modernisation and the second wave programmed over the period between 2005 and 2020.

The foundations of the new modernisation programme were defined in April 2002. They were based on new technologies, equipment modularity and interchangeability and factored in the lessons learnt from the line 14 operation. Within this framework the automation of an existing line was considered. However, although the creation of an entirely automatic under – ground line did not present a particular challenge, no network had ever launched a conversion project without traffic interruption.

The choice of an automatic line depends on the benefit brought by integral automation of train movements. The three main advantages, which are universally recognised, are:

  • Adaptability and the potential tailoring of the offer
  • Increase in commercial speed
  • Traffic reliability improvement.

Applying these criteria made it possible to shortlist several lines. Line 1 met all of the conditions.

As an essential artery of the public transport network in the Paris region, line 1 is extremely responsive to variations of transport demand due to its numerous connections and the districts it serves. The analysis of its traffic flow showed that in spite of a satisfactory average offer, line 1 was not in tune with passengers’ expectations and thus did not offer the expected service. In particular, there was an overload during morning peak hours and in the evening after 8pm. There is also a significant demand on line 1 at weekends and during holiday periods.

Like all underground lines, line 1 was affected by repetitive operational difficulties: track and tunnel intrusions, and carriage access door obstructions, which kept trains on stations. The number of such incidents, related to a more general evolution of behaviours, increased by 75% over the last 10 years. They caused almost 60% of the delays experienced on the entire network; they accounted for 72% of delays on line 1.

Platform screen doors, which are a critical component of the automation of a line, considerably reduced these kinds of difficulties. They help to avoid severe passenger accidents, such as falls on tracks and suicides.

It is with this backdrop that, in January 2003, the feasibility study of the integral automation of a Paris subway line was launched. The findings presented in December 2003 to the General Management concluded that the project was technically difficult but feasible and eco-nomically worthwhile. The investment overcosts would be offset by productivity gains.

As for the choice of line, the working group recommended line 1 which was the only line of the network for which all subsystem components making up the future automatic system were at the end of their life cycles, thus avoiding crippling overcosts of non-amortised equipment. The only contentious point of this analysis was the rolling stock which had been introduced on line 1 in 1997 but which could be transferred to line 4 – the fleet of which was roughly equivalent, thus authorising the purchase of new trains without driving cabins.

As a conclusion, the automation of line 1 was considered to be technically possible, yet complex as it deals with the busiest line on the network. The social dimension was regarded as fundamental to the success of the operation. The economic dimension was considered to be manageable.

Management structure

The automation project of line 1 was approved by the RATP Board of Directors on 30 April 2004 and by the Railways Authority (STIF) on 10 December 2004.

In order to control the risks associated with the project, RATP decided to set up an innovative management structure. The automation of line 1 was a complex undertaking which was not suited to RATP’s conventional project management organisation.

The project was divided into the follow ing four technical projects and an organisational project:

  • The study and supply of new rubber-tyre rolling stock and its associated maintenance infrastructures together with the modifica – tion of existing equipment in order to be operated in conjunction with platform screen doors
  • The study and supply of an Automated System of Trains Operation (SAET), including the OCC, platform screen doors and management of gaps on curved stations
  •  The study and supply of the audio-visual media providing all the communication between passengers, the operator and the OCC
  • Studies and works to install platform screen doors and equipment required by SAET on line 1
  • The operation and maintenance organisa – tional adjustment in line with the future automated line.

A global project management structure to which five project managers reported – corresponding to the disciplines described above – was created as soon as the feasibility study was completed, by bringing together the skills required for managing the whole operation.

The global project management structure was entrusted with the responsibility of managing risk and the interfaces between projects, among other things. In this capacity, it managed the whole system’s integration. To achieve these objectives, several tools were developed, in particular with respect to project risks and interface management.

Platform screen doors and gap management (curved stations)

During feasibility studies, installing platform screen doors by retrofitting on the line was considered to be technically feasible. An operation of this nature had already been carried out on the Hong Kong network on three existing lines. However, it seemed to be a more complicated exercise in the case of line 1, as it was to be performed on century old platforms during the interruption of service. The working group thus proposed the installation of halfheight platform screen doors.

This new technology, developed in Japan in early-2000, offered the twofold advantage of allowing to be integrated on line 1 stations more easily and also making the adaptation work more simple, in particular the potential displacement of existing lights in stations. However, manufactured equipment meeting the needs expressed by RATP did not exist off-the-shelf. The height of platform screen doors used in Japan was between 1m10 and 1m20.

So, RATP decided to test 1m50-high platform screen doors on two stations on line 13: Saint-Lazare and Invalides. Three platforms were equipped with three different types of equip – ment in early-2006. After several months of trials, the technical feasibility and the benefit of the equipment for passengers were proven.

Installing half-height platform screen doors required strengthening and preparing the platforms. Of course, line 1 platforms had not been originally designed to sustain this kind of equipment and to absorb the associated pressures. Furthermore, the fact that the installation work was carried out at night meant that electrical connection fixation and passage holes were to be prepared prior to assembly in order to minimise installation time.

In spite of the trial carried out at Saint- Lazare, the lack of feedback on this type of technology led to several technical and functional amendments, in particular at the interface level between the platform and platform screen doors. Moreover, each platform was the subject of a tailor-made solution.

Also to be mentioned here is the specific case of Bastille station, which featured tight curves on entry and exit of the station, a significant difference in height between the middle and the end of the platform and the existence of a bridge rail. The overseeing authorities therefore required a specific safety features analysis for this station.

Despite all these difficulties, work pro – gressed without incident. The first platform screen doors were installed on a dead section of the platform at Porte Maillot station in November 2008 and on an operating station at Bérault station in March 2009. The final station to be equipped was Bastille in April 2011.

Installing platform screen doors generated an additional challenge on curved stations. In addition to the potential risk of falling through the gap between the rolling stock and the platform, the risk of a customer being stuck between the train doors and the closed platform screen doors was identified.

On a conventional line, these risks are covered by the driver’s vigilance. On automatic lines, it is necessary to make arrangements to allow for the detection of both issues, to prevent the departure of the train.

With respect to falls, a step known as ‘passive’ was installed 20cm under the platform head in the zone between the bottom of the carriage and the bogie. This step, made up of rubber teeth, allows for nondestructive contact with the rolling stock.

To prevent jamming, an emergency unlocking bar was installed on the track side in zones where the residual space between the train doors and the platform screen doors is greater than a reference value. In the case of some very large gaps, like those on the ends of the Bastille platforms, the unlocking bar was doubled with a presence detection system containing laser sensors.

Rolling stock

As far as rolling stock was concerned, it was decided to purchase new rolling stock adapted to the integral automatic system and to transfer existing rolling stock from line 1 to line 4.

The rolling stock fleet of line 4 was compatible with that of line 1 and was due to be commissioned between 2008 and 2011. This scenario offered the benefit of avoiding the crippling costs of modifying rolling stock and the significant investments of associated undertakings.

In accordance with the feasibility study orientations, the specifications of the new rolling stock, known as MP05, took over from the main functionalities of the driverless mode of line 14, which were tried and tested, thus avoiding rolling stock tuning interfering with that of automatisms. Leveraging the experience acquired, a number of functionalities evolved or were adapted to the characteristics of line 1.

Among the functional evolutions of MP05 were:

  • The installation of a cooling ventilation
  • The predisposition to accommodate multimedia equipment
  • The modification of the recording of operating parameters.

The obsolescence of components and the developments carried out on the last generations of rolling stock were also taken into account.

Automatisms

The specifications of the train operation automation system of line 1 were taken from that of line 14 with two additional functions: the creation of a reduced adherence step on the over-ground part of the line, and the ability to start and stop automatic trains for a new service anywhere along the line.

The automatisms purchase deal comprises the automatic pilot, the data transmission system, traction equipment command and the monitoring system.

The renewal of the signalling system, the audio-visual media including the audio connections between the OCC, passengers and the operating staff performed by the TETRA digital radio network, the onboard CCTV performed through Wi-Fi technology and the platform screen doors video monitoring system, were all purchased through deals. Relay interlocking was replaced by safety software interlocking.

The integration of onboard systems and audio-visual media in the rolling stock was carried out on a railway ring, at the railway testing Centre at Valenciennes (CEF) which was specially equipped for pneumatic tyre stock. This provision made it possible to reduce the number of nights required for the tuning of the system and facilitated the organisation of work on site.

The organisation of the line

As was underlined in the feasibility study findings, the social dimension of the project was regarded as fundamental to its success.

By 2002, a communication campaign was started which involved staff and trade-unions. More than 3,600 operating staff were made aware of the subway modernisation programme and invited to engage with the management teams.

The social follow-up was then negotiated with the trade-unions on the basis of evolution of professional paths and the definition of the new job profiles induced by the transformation on the organisation of transport on line 1. Those were mainly aimed at improving customer service in stations and also at strengthening local management.

An agreement protocol was signed on 12 July 2004.

In parallel with technical developments, local consultation continued under the responsibility of the line 1 Director which led to two protocol agreements; one for the organisation of line 1 transport and stations, the other on driving jobs. Both protocols were signed with trade-union representatives on 19 December 2007.

Migration to the new system without interruption of traffic

To be able to go from conventional operations with drivers to complete automatic operations (driverless) without interruption of traffic, two transitional periods were defined. The first consisted of operating line 1 with the rolling stock under manual control and platform screen doors which were gradually being installed. The second consisted in operating the line under a combination of rolling stock under manual control and automatic shuttles introduced gradually as the delivery of the new rolling stock took place.

In order to manage the risks associated with the first phase, which were linked primarily to the ability to undertake the whole work during the interruptions of service at night, RATP required the manufacturers to develop highly effective test-benches in factory set-ups, in order to minimise the on-site tests. Furthermore, it was decided to carry out dynamic tuning and integration tests at the Railway Testing Centre at Valenciennes rather than perform them on line 1 itself.

A special organisation under the project management team was to manage priorities and synergies of night works, depending on the needs of assembling the platform screen doors and automation work.

In all, approximately 13,500 on-site opera – tions were carried out from the autumn of 2007 until the commissioning of the first automatic trains on 3 November 2011. The only interruptions of traffic related to the drying of the concrete flagstone during the strengthening of platforms (one weekend per station) and the final system integration tests (closing of a number of line sections in the evening at 11pm or on Sunday mornings until 10am).

In order to negotiate these interruptions, an effective communication campaign was set up using the full range of available media supports: newspapers, posters, in-station broadcasting and the internet.

The number of passengers inconvenienced during this period, i.e. compelled to alter their trip or use an alternative means of transport such as the dedicated shuttle service, was 0.7% –which met the organising authority requirements.

In order to manage the risks associated with the second phase, the line 1 operator had to focus on staff safety while moving on the track, mainly in the terminus areas. The principle that was chosen was to set aside a number of secondary tracks for moving automatic trains. Therefore, terminus were organised in to red zones where movement was prohibited and to green zones where movement was authorised. Technical conditions and operating procedures were defined for the purpose of managing these zones. Those have evolved over time until the complete automation of the line.

Conclusion

On 3 November 2011, Pierre Mongin, Chairman and Chief Executive Officer of RATP, inaugurated the customer service of the first automatic trains in the presence of the Minister for Transport and the President of the Railways Authority. The technical challenge had been successfully addressed.

After the technical challenge, it was down to the operator to meet the challenge of mixed operation. The system training and the appropriation of the new operating procedures became quickly effective thanks to adapted training and the shepherding of the project teams. The integral automation of the entire line will be effective by the end of 2012.

With the automation of line 1, RATP has pursued its vocation of pioneering urban transport and confirmed its international leadership in the field of automatic subways. This know-how is now at the disposal of the RATP Group to develop across the world, future automation projects of existing lines leveraging the line 1 project.

 

About the author

Gérald Churchill graduated as an engineer from the Ecole Supérieure d’Electricité. He joined RATP in 1978 and occupied several posts in maintenance and engineering before becoming Head of Metro line 14 in January 2001. In March 2004 he was appointed as Project Manager for the automation of Metro line 1. Gérard has represented RATP in several European and international standards bodies and in UITP Working Groups.

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