Senior Management

Omesh Motiwalla
Chief Financial Officer & Company Secretary 


Omesh is a Fellow of the Institute of Chartered Accountants in Australia and New Zealand with over 25 years experience in commercial and public practice specialising in mining, mining services and the oil and gas sector. Omesh was previously a Corporate Finance Partner of Deloitte in Western Australia. Omesh’s experience includes corporate advisory services having consulted on and managed numerous transactions involving private and publicly listed companies.

David Sala Tenna
Chief Operating Officer
BE (Mech Eng)

Dave co-founded GR Engineering. He is a mechanical engineer with over 30 years' experience in the mining industry as a general manager, project manager, project engineer, design engineer and construction manager. Dave has an outstanding track record in the timely and efficient delivery of many feasibility studies and design and construction contracts under a variety of contracting models for a wide range of commodities including gold, nickel, tantalum, lead, zinc and iron ore and his knowledge in all facets of project execution provides dedicated management support to project managers and execution teams.

Antonio Cinanni
Manager - Projects

BE (Mech Eng)

Antonio is a mechanical engineer with over 20 years of industry experience in the metals and mining sector having led and managed complex projects and feasibility studies. With a leadership, strategy development and investment studies background, Antonio has technical engineering expertise and a strong project and operations skill base. Antonio has predominantly worked on high value brownfield projects and studies where he managed EPCM and EPC projects and integrated project teams across the iron ore and nickel sectors. Antonio brings extensive knowledge through his management of large scale projects and development activities associated with studies, design development, estimation, schedule development, execution strategies and resource planning and management.

Aaron Dorai-Raj
Manager - Projects
BSc (Hons)

Aaron is a project manager and engineer with over 15 years of industry experience in the mining sector.  Aaron has spent the majority of his career at GR Engineering and throughout that time has been directly involved in a wide variety of roles and capabilities including project engineering, mechanical engineering and design, construction interface, commissioning and commissioning management, scheduling and project controls, cost estimation and study management, project management and peer review.   Aaron has a proven track record for the timely and successful delivery of Greenfields and Brownfields projects and studies both in Australia and overseas in commodities including gold, base metals, industrial minerals and mineral sands..

Tom Marshall
Manager - Eastern Region

BE (Civil)

Tom is a skilled manager with over 20 years' experience working in the engineering and construction fields for the mining industry. He has global project development and execution experience across Mineral Processing Plants in Africa, Australasia, South and North America. His recent experience includes strategic project assessment and development, capital estimates and contract negotiations for GRES and previously with Sedgman Limited. Tom is a Civil Engineer and Manager with broad industry experience working closely with clients to develop and build mineral processing plants globally.

Matthew Sala Tenna
Manager – Engineering
BE (Mech Eng)

Matthew is a mechanical engineer with over 12 years of experience in the design, construction and commissioning of minerals processing plants. He has experience with a range of commodities including gold, base metals, industrial minerals and paste plants both in Australia and internationally. Matthew has a proven track record in the timely and reliable delivery of both Brownfield and Greenfield projects under a variety of contracting models.

Peter Allen
Manager - Technical Services

BE (Metallurgy)

Peter is a metallurgist and member of the Australasian Institute of Mining and Metallurgy. He has over 35 years' experience in the Australian mineral processing industry, initially in operational roles at gold and base metals projects in Western Australia, New South Wales and Tasmania, before moving to JR Engineering as Process Manager and subsequently GR Engineering. Peter’s skills and expertise extend to process design, process equipment selection and evaluation, testwork initiation and development through to plant commissioning and operational support. Throughout his career Peter has been responsible for and had key input into the process engineering and design of an extensive number of highly successful minerals projects both in Australia and overseas.

Brian Masters
Manager - Project Development

NHD (Extractive Metallurgy), BComm (Operations)

Brian is a metallurgist with over 25 years’ experience in the field of metallurgical engineering both with plant operations and project implementation. He has extensive experience with the design, implementation and commissioning of capital projects as a process engineer and project manager including experience in the financial evaluation of process projects. Brian has been actively managing feasibility studies for over 15 years covering a range of commodities and project locations.

Stephen Oliver
Manager - Commercial

Stephen is a civil engineer with over 15 years experience in project execution and close out in the mineral processing, oil and gas and telecommunications industries. Stephen brings his experience from having led and managed complex projects, as well as managing the commercial function of the business, to create a unique skill set that allows for a practical approach in contract negotiation and development of commercial models to allow for the effective delivery of projects. As Procurement Manager he reviews purchases and contracts for conformance to company policy, negotiating with vendors to secure the most advantageous terms.

Ryan Hahn
Manager - HSE

Ryan has over 10 years experience working in health, safety and environmental across the construction industry. He is motivated and dedicated to provide the best systems, processes and tools to enable our people to do their work safely and holds a Diploma of Work Health and Safety, Quality and OHS Management Systems Lead Auditor and ICAM Lead Investigator. Ryan had an integral role in the development of our HSE Management systems to ISO 45001 and the Australian Government building and construction WHS Accreditation Scheme.

Adrian Federici
Manager - Human Resources


Adrian received his qualifications in Human Resources and Industrial Relations from the University of Western Australia. He is a purpose driven leader with over 20 years’ experience in operational, corporate, and executive HR and IR leadership roles. He has proven experience in driving cultural and business performance outcomes. Experienced in multiple work locations including Australia, Asia, and Africa he is a focused business leader with a proven track record in delivering practical people infrastructure and strategy in both private and publicly listed organisations.  

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