A WA parliamentary question seeks specific financial impact data for several initiatives aimed at minimising METRONET project cost escalations, focusing on ballast spreaders, spoil reuse, solar-battery systems, and hydrogen fuel alternatives. The answers provide some data on material savings, recycled content, diesel reduction and carbon emission savings, but not direct financial figures.

AnsweredQoN 737Legislative Council
Asked
16 October 2025
Portfolio
Transport

QuestionView source ↗

I refer to the Minister's answer to Estimates pre-hearing questions in relation to METRONET cost escalations in which it was stated "numerous initiatives have been undertaken over the life of the METRONET program to minimise the impact of external factors that have pushed project costs up", and the Minister's response to follow up questions in question on notice 600 in which a list of initiatives taken to minimise factors pushing project costs up was provided, and I ask: (a) in relation to "using cutting-edge Reptail ballast box spreaders on the Morley-Ellenbrook Line project, improving efficiency and reducing the amount of equipment needed", what was the positive financial impact on the project in dollar terms as a result of this initiative; (b) in relation to "sourcing and reusing on site over 3 million tonnes of spoil on the Yanchep Rail Extension", what was the positive financial impact on the project in dollar terms as a result of the initiative; (c) in relation to "used solar-battery systems at a number of site offices to reduce diesel use", what was the positive financial impact on the project in dollar terms as a result of the initiative; and (d) in relation to "using hydrogen as a diesel alternative on the Byford Rail Extension, which lead to a 19 per cent increase in fuel efficiency", what was the positive financial impact on the project in dollar terms as a result of the initiative?

AnswerView source ↗

Answered
18 November 2025
Responded by
Parliamentary Secretary to the Minister for Transport
Response time
7 days
(a)        The Reptail box spreaders resulted in zero ballast material waste compared to the usual 20 per cent, providing a saving of 38,079 tonnes of material during construction and 152,316 tonnes over the lifespan. It also resulted in a 50 per cent decrease in labour and equipment, and a saving of 1,660 tonnes of carbon dioxide emissions over the lifespan.
(b)        The 3 million tonnes of spoil re-use on the Yanchep Rail Extension contributed to an overall 90 per cent recycled content rate.
(c)        The Morley Ellenbrook-Line project used WA’s first 50kVa hybrid solar battery to power the Whiteman Park Station site, saving an estimated 23,530 litres of diesel. This contributed to a saving of 67 tonnes of carbon dioxide emission on the project. The Byford Rail Extension also used a hybrid solar battery system, with the lifecycle study of this project yet to be completed.
(d)       The use of the renewable biofuel HVO100 (100 per cent Hydrotreated Vegetable Oil) resulted in a saving of approximately 7.9 tonnes of carbon dioxide emission on the Byford Rail Extension.

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