Feasibility of replacing sand with aluminium oxide for tram use

Melbourne’s trams currently use sand to stop safely, however aluminium oxide might enable better operational and sustainability performance. Its use is yet to be sufficiently examined and understood in the Australian context.

This project involves investigating the use of aluminium oxide in the following three areas:

1. Health impacts on humans and animals;
2. Environmental impacts; and
3. Track-performance impacts.

Participants

• Yarra Trams
• RMIT University

Project background

Yarra Trams would like to investigate the potential benefits of replacing the use of sand with aluminium oxide (AO) in trams in Melbourne. Sand is used in high volumes across the network whereas a lower volume of AO is reportedly required. The use of AO is reported to lead to improved brake efficiency, lower wear and tear and lower financial costs (due to lower volumes used and higher efficiency).

This project scope has been developed in collaboration with RMIT researchers and will help support Yarra Trams’ decisions towards adopting technology that will improve Australia’s transport system efficiency and sustainability.

To increase friction (track adhesion) between the wheels and tracks so that the tram can stop safely, sand is generally used by the tram either automatically or manually. Despite the removal from the tracks and the reuse or recycling of over 95% of the sand, a small portion of the sand is washed away from the tracks by rain or becomes airborne during windy and dry weather conditions.

However, the effectiveness of AO is yet to be fully examined and understood in the Australian context. Three factors are important to consider as part of the decision to replace sand with AO:

1. Health and safety;
2. Environmental impacts, including carbon footprint; and
3. Asset performance.

Project objectives

• Part A: Summarise the known and suspected impacts of AO on environment and health;
• Part B: Conduct a life cycle assessment of AO and sand;
• Part C: Summarise the published effects of AO on the rolling stock’s braking and take-off performance; and
• Part D: Trade-off and consolidate the impacts estimated in Parts A, B, and C.

Please note …

This page will be a living record of this project. As it matures, hits milestones, etc., we’ll continue to add information, links, images, interviews and more. Watch this space!