Introduction
Automatic platform screen doors also known as platform edge doors, are automated doors installed at metro or subway stations which separate the platform from the train corridor or tracks. These doors help prevent accidental entry and exit from the platform area and provide a physical barrier between commuters and moving trains. In recent years, more and more metro rail networks across the world have started implementing automatic platform screen doors for enhanced safety and improved passenger flow.
Need for Platform Screen Doors
With increasing ridership numbers, overcrowded platforms and rushing commuters have posed safety challenges for metro rail operators globally. Each year hundreds of accidents occur worldwide where passengers accidentally fall onto the tracks due to overcrowding or negligence. Platform screen doors act as a physical barrier which prevents such accidents. They efficiently control passenger movement and avoid dangerous situations of people inadvertently walking onto the tracks. These doors also make unauthorised access to tracks very difficult which enhances security. For commuters, they provide a psychological feeling of safety while waiting or boarding trains.
Advantages of Automation
Earlier, many metro networks used manually operated sliding doors as platform barriers. However, these manual doors had limitations in terms of operation speed and coordination with train arrival/departure timings. Automatic platform screen doors overcome these limitations through sensors and programmable logic controllers. Their key advantages include:
– Faster operation: Automated doors open and close much quicker in sync with train arrival/departure schedule ensuring smoother passenger movement.
– Increased Uptime: Compared to manual doors, the uptime of automatic screens is higher since they have less mechanical wear and tear.
– Remote Monitoring: Sensors and controllers allow centralised remote monitoring of door status for preventive maintenance.
– Energy Efficient: New generation door panels use light weight materials and efficient control systems resulting in lower energy consumption.
Platform Screen Door Designs
Platform screen doors come in various designs suited for different metro rail network specifications:
– Half Height Screens: Consisting of doors extending only partially above platform level, mainly used where platform space is limited. However, they provide lesser safety.
– Full Height Screens: Full height clear polycarbonate screens extending from floor to ceiling of the platform provide maximum safety but require more space.
– Single & Double Leaf Doors: Single leaf or biparting doors used depending on volume of passenger traffic and station infrastructure.
– Frangible Design: Newer screen designs use frangible or break-away panels that give way on slight impact preventing entrapment between train and screen.
– Curved Door Panels: For stations with curved platform edges, door panels have a contoured design following the curve of platform.
Installation and Integration Challenges
Retrofitting automatic platform screen doors in existing metro networks is a complex undertaking due to various infrastructure constraints. Stations may need modifications for proper door alignment and integration with other station systems. Project scheduling becomes crucial to limit disruption of train operations during installation work. Other challenges include:
– Space Constraints: Integrating large full height screens within limited space of older stations requires structural modifications.
– Signalling Integration: Door control systems need tight integration with train signaling, telecommunication and SCADA systems.
– Platform strengthening: At some locations, platform slabs may need reinforcing to bear increased load of screen installations.
– Platform alignment: Door positions have to precisely match dynamic train-platform gaps requiring high-degree alignment accuracy.
– Interchange stations: Coordination of door operation across multiple intersecting lines pose additional technical challenges.
Case studies of Platform Screen Door Implementations
Let us look at how some of the major metro networks across the world have implemented automatic platform screen doors:
Tokyo Metro, Japan:
Tokyo Metro was one of the early adopters of automatic platform screen doors way back in the 1960s. Currently, all 206 metro stations under Tokyo Metro are equipped with full height frangible screen doors. The doors have reduced accidental deaths to almost zero.
Seoul Metro, South Korea:
Seoul became one of the first Asian cities to install platform barriers in the 1980s to address high passenger volume. Its current Phase 1 and 2 lines consist of 251 stations with proper integration of automatic screen doors.
MTR, Hong Kong:
The metro network in Hong Kong upgraded platform barriers to automatic screens in the 1990s and completed work across 79 metro stations by 2004. Its new Canton metro line also features full height automatic doors.
Singapore MRT:
Platform screen doors were installed by Singapore in 1987 to prevent passenger fall incidents. The initial phases used full height rigid screens which were later upgraded to break-away frangible panels across the network.
Delhi Metro, India:
Delhi Metro started retrofitting its oldest stations with automatic screens from 2012 onwards and completed work across 191 stations by 2018. Stations on its Phase 4 expansion are also equipped with full height platform screen doors.
Conclusion
As metro rail ridership numbers continue to surge worldwide, implementation of Automatic platform screen doors has become imperative from safety perspective. While upfront capital investments are high, their long term benefits far outweigh initial costs by preventing accidents, controlling passenger flow and enhancing security in a hassle-free manner. As technology keeps advancing, design and size of these safety barriers will continue to evolve as per network requirements. Well planned door installations will play a key role in securing the future of urban mass transit systems globally.
*Note:
- Source: Coherent Market Insights, Public sources, Desk research
- We have leveraged AI tools to mine information and compile it
