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Investing in passenger safety

Posted: 15 February 2008 | Serge Lagrange, Metro Operations Director, RATP | No comments yet

Several metro networks are progressively introducing platform screen doors, set-up at the edge of platforms to prevent passengers falling on the tracks. Platform screens remove the risk of accidental falls and prevent suicide attempts. Platform screens also improve the general sense of safety of the passengers waiting at platforms. In addition, they contribute to improving the regularity of train movements by shortening waiting times.

On the Paris network, platform screens are regarded as indispensable on lines that are automated (Line 14 was equipped at the outset and the current automation of Line 1 includes the fitting of platform screens). On non-automated lines, platform screens bring advantages in terms of safety, regularity and comfort.

Several metro networks are progressively introducing platform screen doors, set-up at the edge of platforms to prevent passengers falling on the tracks. Platform screens remove the risk of accidental falls and prevent suicide attempts. Platform screens also improve the general sense of safety of the passengers waiting at platforms. In addition, they contribute to improving the regularity of train movements by shortening waiting times. On the Paris network, platform screens are regarded as indispensable on lines that are automated (Line 14 was equipped at the outset and the current automation of Line 1 includes the fitting of platform screens). On non-automated lines, platform screens bring advantages in terms of safety, regularity and comfort.

Several metro networks are progressively introducing platform screen doors, set-up at the edge of platforms to prevent passengers falling on the tracks. Platform screens remove the risk of accidental falls and prevent suicide attempts. Platform screens also improve the general sense of safety of the passengers waiting at platforms. In addition, they contribute to improving the regularity of train movements by shortening waiting times.

On the Paris network, platform screens are regarded as indispensable on lines that are automated (Line 14 was equipped at the outset and the current automation of Line 1 includes the fitting of platform screens). On non-automated lines, platform screens bring advantages in terms of safety, regularity and comfort.

In this context, RATP is conducting a project in four stages:

  • Experiment on Line 13
  • Installation on Line 1 with the automation of the line
  • Installation on the section of Line 13 with the heaviest traffic to improve the overall reliability of operations on this line
  • Eventually, extension to other lines of the network

Objectives of fitting platform screens

Assessment of the Line 13 experiment with platform screens

During the last quarter of 2006, RATP experimented with three platform screen prototypes in the Saint-Lazare and Invalides stations. The objective of this experiment was to demonstrate the feasibility and the operational benefits of the platform screens on a non-automated line, as well as to verify the proper integration of half-eight platform screens. Line 13 stations were selected as being representative of stations that are particularly critical because of their high volume of passengers.

A poll has shown that the equipment was well received. The improved safety on the platforms is a factor of the increased peace of mind indicated by 90 per cent of passengers. Also, it was observed how parents allowed their children greater freedom of movement in contrast to those on non-equipped platforms.

The equipment has been well received by drivers, too. They have experienced no particular difficulty and recorded an improvement in the flow of passengers on the platform. The experiment demonstrated that platform screens helped drivers to supervise the closing of the doors and therefore, the actual waiting time.

To make passengers safe whilst waiting at platforms

In stations with the heaviest traffic, passengers are crowded on platforms and become aware of the risk of a fall onto the tracks. Platform screens completely remove this risk. This in turn allows passengers to freely use the entire space available on the platform, which contributes to a sense of increased comfort.

Contributes to adherence to the timetable

The risk of a passenger fall on crowded platforms leads drivers to feel apprehensive when entering the station. This in turn causes them to reduce the speed of their train, leading to delays and to a direct impact on the regularity and fluidity of traffic.

To limit accidents and trespassing on tracks

The Paris metro has 5,000 incidents each year. Incidents often require service to be discontinued. This is particularly detrimental to the operation of the lines with heavy traffic, like Line 13. Platform screens are estimated to result in a 40% reduction in these incidents.

To ensure the proper supervision of passenger transfers

Proper supervision of passenger transfer is a condition to complying with pre-defined dwell times. The variability of dwell times is extremely detrimental to operations. A train delayed at a platform has to take in a larger number of passengers at the next stations. This in turn will delay its progress along the line and also that of the following trains.

Project specifications

Reduction of the gap between train and platform screen

Feedback from the experiment with platform screen prototypes led to modifying the specifications for the layout of platform screens. The gap between train and platform screens was reduced by five centimetres compared to the best prototype. The foot of the frame of a platform screen is now along a tangent relative to the layout, and cannot be set closer to the track axis.

Platform screen functions

RATP has decided to retain the 1.70 metre high platform screen – known as the half-height platform screen – for implementation. This is considered better adapted to the existing infrastructure of the Paris metro and has some additional advantages, such as:

  • A reduction is costs compared to full-height platform screens
  • Faster installation
  • Better technical and visual integration in the Paris metro

Design and materials

Considering the technical and functional constraints, the main characteristic of the platform screens is the high level of transparency retained. This effectively preserves the perception of space for passengers and the visibility of passenger information and advertisements located on the opposite platform or wall. Although platform screens have a height of 1.70m, the absence of glass bead – a small moulding that secures glass to doors – in some of the upper parts of the window pane contributes greatly to this perception.

Unlike the prototype installed in 2006 at Invalides station, platform screens, (as they will be deployed on Line 13), have essentially become a platform fixture occupying a natural space within the platform area. The platform screen panels are, for the greater part, windowed panels covered with film to protect against graffiti. The support structures are in anodised aluminium and the vertical round profiles framing the platform screen, like the tops, are made in composite material.

Description of the platform screen system

Platform screens completely separate the platforms from the tracks, while allowing the transfer of passengers at platform doors which open in line with the doors of the train. A platform screen is made of platform doors alternating with emergency doors, as well as fixed elements and a side door to access the tracks at both ends of the platform.

Movable parts include:

  • Platform doors; sliding power-driven doors providing a 2.15 metre wide opening
  • Emergency doors positioned between the platform doors enabling passengers to exit a train not properly berthed in front of the platform doors. These are also equipped with a panic bar, enabling passengers to open the doors manually. The dimensions ensure that whatever the particular location of the train or platform, emergency doors provide a passage at least 80 centimetres wide
  • Platform side doors are installed at both ends of a platform to enable staff and emergency forces to access the tracks, as well as give passengers access to the platform from the tracks during an evacuation

Installing platform screens

Installing platform screens requires specific civil engineering, for example:

  • Reinforcing the platform edge to withstand the increased efforts sustained due to the platform screen, such as the weight of the platform screen and crowds pushing on the screens
  • Working within the tympanum at some stations when the platform is not long enough to install the platform side doors at the ends of the platform which would normally facilitate the evacuation of passengers when a train is blocked inside a tunnel

The layout of platform screens ensure that train doors come in front of the platform doors when the train is properly berthed at the normal stopping point. However, while this stopping point is usually the one used prior to fitting the platform screen, it can be changed at short platforms to give room for installing at least one platform side door while avoiding extensive tympanum works. Thus, only one opening is made inside the tympanum at the other end of the platform, to provide proper access to the tunnel. The platform is also extended by a light metallic structure and the stair between platform and track is moved. The works are carried out at night and therefore have no impacts on the service to passengers.

Stations are equipped with platform screens in a continuous way along the line. Once a platform has been made ready, installing the platform screens does not require shutting down the station. A platform screen is put into service as soon as it is installed and as a result, platform screens along an un-interrupted section of the line are in full operation even before all the platform screens are installed.

For a station with two platforms, 32 nights are required for completing the installation and putting into service 30 platform doors, as well as the accompanying platform side doors. A specific organisation of the work teams makes it possible to install the two platforms simultaneously.

Prospects of equipping the metro network

It is possible to consider the equipment of the whole network over time and line by line by fitting each line with platform screens. This ensures that passenger safety is improved for the whole line rather than just on some sections. Fitting platform screens also improves the supervision of passenger transfers and therefore compliance with timetable dwell time. It also prevents intrusions on the track. This removes two causes of timetable irregularity which are otherwise difficult to justify. This considerably improves the regularity of traffic on the line, particularly at peak hours. To equip all the lines with platform screens, as on Line 1 and 13, would extend to them the benefits observed on Line 14. This is considered an effective answer to the difficulties experienced on metro lines in Paris.

Parameters to take into account for extending platform screens to the whole network

Automation of existing lines

Installing platform screens on a line does not incur costs that would prevent later automation. Platform screens can be installed on lines that are not expected to be automated. However, should a line already equipped with platform screens be automated, the only change to the platform screen control system would be to interface it with the new automatic system operating the trains.

Renewal of rolling stock

The layout of train doors determines the location of the platform doors. Conversely, once the platform screens are installed, it is impossible to switch to rolling stock with a different door layout.

RATP has engaged in a renewal programme where the MF67 rolling stock will be replaced by MF2000 rolling stock that has a different door layout. In this case, the platform screens will only be installed once the new rolling stock has arrived. Similarly, the rolling stock equipped with rubber-tyred wheels will be replaced with rolling stock that has a different door layout. Finally, the MF77 rolling stock will be renovated rather than renewed, which solves the issue of the layout of the doors.

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