Senior Mechanical Engineer

ACCIONA is a global company, leading in the development of regenerative infrastructure that creates a positive impact on society. Our workforce consists of more than 65,000 professionals, present in more than 40 countries across the five continents, all contributing in our mission to design a better planet. Are you a passionate individual who wants to make a difference, promote sustainable development, and find solutions to the biggest global challenges including climate change, overpopulation, and water scarcity? Come and join us in building the infrastructure our planet needs to achieve a sustainable future.

The Project

ACCIONA has been selected to deliver Western Harbour Tunnel – Stage 2, Sydney’s third harbour crossing. The new Western Harbour Tunnel (WHT) will connect to WestConnex at the Rozelle Interchange, cross underneath Sydney Harbour between Birchgrove and Waverton, and connect with the Warringah Freeway near North Sydney.

Project scope includes:

• Construction of approximately 4.8 kilometres of mainline tunnels with three lanes in each direction
• Civil, Mechanical and Electrical fitout of Stage 1 and Stage 2 tunnels
• Surface level work, including on and off ramps and tie-in work to the Warringah Freeway

The Opportunity

In line with the above, ACCIONA are now looking for a Senior Mechanical Engineer within the engineering support team. As the Senior Mechanical Engineer you will play a critical role in the delivery phase of the Western Harbour Tunnel project. You will provide expert technical guidance and engineering support to the construction team, ensuring that mechanical systems are delivered to specification, on schedule, and in compliance with relevant standards and project requirements.

Key accountabilities for the position:

• Respond promptly and accurately to queries raised by the construction team, providing clear and practical engineering solutions.
• Review and interpret design documentation, specifications, and construction drawings to support on-site execution.
• Take ownership of existing mechanical designs by conducting thorough review and familiarisation, enabling informed and confident advice to the broader engineering and delivery teams.
• Liaise with design consultants, contractors, and internal stakeholders to resolve mechanical engineering issues during construction.
• Ensure all mechanical works comply with project standards, relevant codes (e.g. AS/NZS), and safety requirements.
• Contribute to risk assessments, change management processes, and engineering reviews.
• Maintain accurate records of technical decisions, correspondence, and engineering changes.
• Provide mentoring and technical leadership to junior engineers within the support team.

Capability & Experience you will need to have:

• Bachelor’s degree in Mechanical Engineering.
• Prior experience in Mechanical engineering, ideally within transport infrastructure or tunnel projects.
• Strong understanding of construction methodologies, mechanical systems (e.g. MVAC, ventilation, fire safety, hydraulics), and relevant standards.
• Proven ability to manage technical queries and interface with multidisciplinary teams.
• Excellent communication, documentation, and stakeholder engagement skills.
• Experience working on major infrastructure projects in Australia is highly desirable.