Sydney Metro: Enhancing a Global City

Since 2014, WSP, in partnership with Aecom and their architectural subconsultants Cox Richardson and Hassell, have been the technical advisor to Transport for NSW (TfNSW) for the AUD11.5–12.5b project. The team is working collaboratively across a number of disciplines to provide engineering, rail infrastructure and architectural design support to develop the reference design, tender documentation and final business case.

Resilience has been at the forefront of the Sydney Metro design – from station space proofing and land acquisition in the early stages of a project to station planning, station and urban design and integration, and drainage and flooding. Considering these key aspects both independently and together has helped to create a sustainable transport solution. 

Station Planning and Pedestrian Modelling

Sydney stations such as Town Hall and Wynyard face issues of inadequate pedestrian infrastructure which has a knock-on effect across the network. Platform congestion hinders boarding and alighting, and increases dwell times, which leads to delays up- and down-stream of the stations. With this in mind, the design team for the Sydney Metro City and Southwest stations saw resilience as a vital consideration. 

With many Sydney stations designed in the early 20th century, it is no surprise that station infrastructure is limiting the ability of the rail line to move people efficiently. Since the turn of the century, there have been significant advances in signalling and train technology, allowing for train frequency to increase significantly beyond anything previously envisaged. Yet station layout has remained largely unchanged with operating capacity placing significant pressure on the infrastructure.

To minimise issues and costs relating to any future redesign of our Metro stations, the new stations have been modelled to cater for any demand or frequency the service requires. This enables passenger flow to be maintained and Metro services to remain unaffected during peak periods. 

This was achieved using modelling to optimise the location of station elements including escalators, gate lines and walkway configurations. The design was tested against a ‘resilience scenario’ or ‘stress test’ that takes into account a theoretical ‘maximum line’ capacity. 

The benefit of this type of testing is to ensure that line capacity is the limiting factor rather than station infrastructure. While the modelled combination of high frequency and high demand is unlikely to actually occur, performing the exercise ensures the design remains relevant and resilient in the long-term.

To minimise issues and costs relating to any future redesign of our Metro stations, the new stations have been modelled to cater for any demand or frequency the service requires. This enables passenger flow to be maintained and Metro services to remain unaffected during peak periods. 

This was achieved using modelling to optimise the location of station elements including escalators, gate lines and walkway configurations. The design was tested against a ‘resilience scenario’ or ‘stress test’ that takes into account a theoretical ‘maximum line’ capacity. 

The benefit of this type of testing is to ensure that line capacity is the limiting factor rather than station infrastructure. While the modelled combination of high frequency and high demand is unlikely to actually occur, performing the exercise ensures the design remains relevant and resilient in the long-term.

Station and Urban Design

The architectural vision for Sydney Metro stations and precincts addresses five project objectives:

1. an easy customer experience
2.  a fully integrated transport system
3.  responsiveness to distinct contexts and communities
4.  a catalyst for positive change, 
5.  delivering an enduring and sustainable legacy for Sydney

These objectives are aligned to deliver a resilient transport solution that offers a world-class customer experience, transforming Sydney’s transport and enhancing the city’s global and local identity.

Local Heritage

The design of Sydney Metro mirrors some of the distinctive characteristics of Sydney’s heritage and culture, and its other iconic projects such as the Sydney Harbour Bridge, Sydney Opera House and Sydney Olympic Park. Meanwhile, the design allows for flexibility at each station, so each sits in the context of the wider network. 

Seamless Integration 

Sydney Metro has been designed to seamlessly integrate station concourse and entrances with potential future developments, improving customer and pedestrian access, and minimising disruption to the surrounding city, while delivering a functional and economically viable design solution.

Community Legacy and a Design for the Future

The aim is for Sydney Metro to leave a community legacy by creating a simple, flexible design that is sustainable in the long-term and will provide a benchmark for future local and international Metro projects. 

Drainage and Flooding

Resilience in flooding and drainage refers to the ability of infrastructure to be immune to a major storm event and to ‘bounce back’ if any adverse impact occurs. 

For Sydney Metro, flooding would pose a significant issue, as any water entering underground stations would damage station infrastructure. This would cause knock-on effects such as delays, disruption and potential security issues. In addition, there are socio economic impacts resulting from repair works and down time caused when trains are inoperable. 

In designing for resilience, there are two major criteria the Sydney Metro drainage design is based on:

1. Probable maximum flood (PMF), which is defined as the largest flood that could conceivably occur at a particular location
2. A 100 year storm event plus 0.5m of additional height to account for freeboard and climate change (100 year + 0.5m).

Both criteria address the effect of climate change. For Sydney Metro, emergency access to the underground stations has been designed to be above the highest level across the two criteria, while all other entrances incorporate automatic flood barriers that activate when flooding occurs.

Level sensors installed in the drainage system activate the barriers, which eliminates the need for a person to operate them, and eliminates flooding risk during a major flood event where a rapid response time is required.

Open drainage

Open drainage has been designed based on available space. Where there is space, open channels and basins are integrated into the surrounding urban design and are situated at a shallow level with a flat side slope.

Where space is more limited, deeper channels with steep side slopes have been designed, complete with barrier fencing for safety. At an aesthetic level, drainage collection pits also house plants so they can blend in with the urban design of the surrounding areas.  

All design decisions for Sydney Metro have been assessed from a value engineering perspective. A number of alternative solutions have been arrived at to ensure the infrastructure is safe and is resilient as far as reasonably practicable, while also remaining cost effective.

Extensive stakeholder consultation has also allowed for the community — a key stakeholder group and the ultimate end user — to have a major say in the design and future-proofing of the Sydney Metro infrastructure.

Designing for Future Environmental Issues and Climate Change

The project addresses environmental resilience through:

• comprehensive shading of station concourses for summer and winter
• weather protection to meet Sydney Metro requirements
• secondary canopies at stair, lift and concourse entry points
• inclusion of a drought tolerant tree canopy at station plazas
  integrated photovoltaic systems producing a minimum of 20% of annual low voltage operational energy required for large concourse canopies
• rain water harvesting for reuse in bathrooms and on landscaping
• high efficiency fixtures and fittings
• design aligned to the Department of Planning and Environment’s urban renewal strategy
• corridor land freed up for use as public open space
• space reserved for an active transport corridor
• active and public transport options prioritised over private vehicle use.