Bayswater Station – Concept Design

  • Client: The Public Transport Authority of Western Australia (PTA WA)
  • Project Location: North-East Perth, Western Australia
  • Date: October 2019

The new Bayswater Station project will become a key METRONET precinct with the Midland Line, Forrestfield-Airport Link and Morley-Ellenbrook Line connections, giving people the option to travel to the Airport, Swan Valley tourist region, the CBD and beyond.

The key features of the project include:

  • constructing a new four-platform station long enough to accommodate six-car trains on a higher rail bridge over King William-Coode streets
  • Additional rail infrastructure between Bayswater and Meltham stations
  • Whatley Crescent-Beechboro Road South connection under the railway
  • Integrating bus services with the local road network
  • Building an elevated Principal Shared Path along the Whatley Crescent side of the rail bridge
  • Upgrading the pedestrian underpass at Leake Street

eTool were engaged by the PTA WA to perform a Life Cycle Assessment (LCA) at the Concept Design stage of the new Bayswater Station and surrounding railway infrastructure. The modelling helped identify key environmental impact areas for the project over its estimated 120 years lifespan.

LCA Scope

eTool was tasked to provide LCA of the station Concept Design as part of the METRONET Sustainability Strategy 2019-2022, which requires the integration of life cycle design into the planning process of METRONET projects.

The Scope of the LCA included all works associated with:

  • Entry buildings for the station, including retail tenancies and plant room
  • The station platform
  • Bridge works
  • Rerouting of the Principal Shared Path (PSP)
  • New railway infrastructure (including track, sleepers, ballast, signalling, etc.) for the station as well as a turnback facility
  • Lighting
  • Other operational energy and water
  • Additional civil works including bulk earthworks, modifications to the surrounding road network and a new bus laydown area.

Results Summary

The assessment was undertaken comparing the Concept Design against a Reference Case, or Business as Usual.  The Business as Usual is a code compliant / standard practice version of the design and represents expected normal industry practice, code compliant energy efficiency and construction techniques and common materials selection.

The LCA of the Concept Design highlighted that:

  • The project could demonstrate a reduction of life cycle GHG emissions by 3.6% through 10% improvement in energy efficiency (Green Star minimum requirements to achieve a 4 star rating)
  • 23% of emissions would be coming from recurring impacts (rail and ballast maintenance, repairs, replacement etc.)
  • 40% of embodied emissions were associated with materials used (upfront emissions A1-A5, from materials manufacturing, transport, and construction)
  • 63% of emissions are materials related (not from the operational energy, module B6)

Developing low-risk low-carbon strategies (up to 60% GHG reduction)

Using eTool’s integrated Life Cycle Design approach our specialists were able to pin-point the environmental hot spots in the design and identify several strategies that if adopted would result in up approx. 60% reduction in life-cycle GHG (CO2eq). The strategies identified included:

  • 30% Blast furnace slag cement replacement in all major concrete elements in the superstructure
  • Utilising high efficiency LED lighting for all internal areas
  • Specifying high efficiency HVAC systems for all air-conditioned areas
  • Utilising LUX sensors to control lighting for all internal areas
  • Sourcing locally produced rail ballast
  • Utilising high efficiency lighting for the station platform, the PSP and street lighting
  • The use of renewable energy generated onsite from solar PV panels

Developing moderate-risk low-carbon strategies (over 90% GHG reduction)

eTool subsequently identified several moderate-risk strategies that would provide further savings if implemented, including:

  • 30% Fly-ash cement replacement in all major concrete substructure elements
  • Using low GWP (global warming potential) refrigerant gases e.g. CO2 or R32
  • Utilising recycled aggregate as a sub-base for the new roads
  • Improved ballast lifespan
  • Smart street lighting
  • Responsible sourcing of steel products (reinforcement, structural and rail)

Low Impact Strategies in Detail

eTool Engineers suggested the following Low Impact strategies for the Bayswater station:

30% Blast furnace slag cement replacement in all major concrete elements in the superstructure

Ground Granulated Blast Furnace Slag (GGBS) is a by-product of the iron making process and is considered a greener construction method because the GGBS requires less than a fifth of the typical energy for conventional cement production, and less than a fifteenth of the carbon emissions. It also offers benefits for workability and in reduced chemical attack/degradation.

Utilising high efficiency LED lighting for all internal areas

As LED lights continue to develop they are surpassing fluorescent lighting in efficiency and provide designers with a greater array of colour and configurations.  The efficiency of LED lights now allows significant savings in electricity providing they are specified appropriately.

Specifying high efficiency HVAC systems for all air-conditioned areas

By increasing the efficiency of the air-conditioners, gains in environmental performance can be made.  Upgrading to high efficiency systems from an EER of 3.0 to 4.4 will have about a 20% saving in cooling energy.

Utilising LUX sensors to control lighting for all internal areas

Lighting systems that have LUX sensors are more energy efficient automatically providing a suitable amount of lighting in changing conditions. For this recommendation, eTool assumed a 10% reduction in lighting demand for internal areas with a high level of natural light access provided by glazed entry doors, curtain walling and windows.

Sourcing locally produced rail ballast 

The sheer quantity and weight of ballast required for the project means that its transport to and from the site has a significant environmental impact. Sourcing ballast locally has the ability to reduce the transport distance and the overall environmental impact significantly.

Utilising high efficiency lighting for the station platform, the PSP and street lighting

As with the internal areas, utilising high efficiency LED lighting for the external lit areas in place of fluorescent lighting has the potential to offer significant savings in electricity.

The use of renewable energy generated onsite from solar PV panels

With the rising price of electricity, the economics of solar are very favourable. Using solar generated power on site results in much lower emissions associated with the building compared to using the fossil fuel powered grid. Feeding out to the grid assumes a net environmental credit as the electricity will be consumed by a neighbouring consumer therefore reducing the demand on the grid. Surplus exported energy can be thought of as an offset for the carbon associated with the materials used in constructing and maintaining the asset.

Use of renewable energy

During the life cycle design process, the options for solar PV were investigated. This process began with a consideration of the operational energy profile and demand. Providing renewable energy for components of the infrastructure was considered, such as the main alignment lighting and eliminated for practical reasons. Solar power for smaller elements such as the vehicle management system and underpass lighting were also considered.

Environmental Initiatives

A number of environmental initiatives that were studied in the early stage of the design have since been implemented in the Issued For Construction (IFC) design, these include:

• Lighting controls

• Increased pavement design life

• Fuel efficiency standards for construction equipment

• Designing out of irrigated landscaping on main alignment

Materials

The Life Cycle Assessment provides a holistic assessment of the environmental impacts of the whole project over it’s whole of life. Within the LCA, all significant building products and materials are accounted for.

Key Initiatives that decrease the environmental impacts associated with the use of materials in the Project include;

• Asphalt design life of 100 years

• Noise wall design life of 100 years

• Barrier design life

• EME Asphalt pilot

• Lean design of bridges at the intersections with Collier Road, Morley Road and Benara Road

• Reduced extent of noise wall, pit and pipe, retaining walls

• Lower Impact Concrete – using Blast furnace slag to reduce Portland cement content

This assessment was conducted by Rob Campbell from eTool.