Newcastle's two main railway workshops are "ready" to manufacture a new suburban train fleet despite the NSW government extending the life of the ageing Tangaras for 12 years so it can "rebuild this industry from scratch".
The Newcastle Herald understands Downer has handed the government an unsolicited bid to fast-track manufacturing the Tangara replacements at Cardiff.
Fellow Newcastle train builder UGL also is understood to be keen to construct the new fleet at the former Goninan site at Broadmeadow.
Downer chief executive officer Peter Tompkins made a direct pitch to Premier Chris Minns when the state leader visited the Cardiff workshop on Wednesday.
Mr Tompkins told the Newcastle Herald that Downer's Cardiff workforce would swell from 150 to 500 and many thousand more in an "energised" Hunter supply chain if it won the Tangara contract.
"We've got a really compelling proposal," he said.
"We've got a supply chain that's engaged and ready, so, when government policy is ready, away we go."
The Cardiff workforce stood at about 500 when Downer was assembling and commissioning the Chinese-made Waratah series of trains for the NSW government 15 years ago.
"I think we're aligned with the government on a need for a sovereign policy that allows one of the last remaining prime contractors with sovereign ownership to engage with local industry," Mr Tompkins said.
"There are others, but they are not headquartered here, and that's the difference.
"Sovereign capability means an investment in local IP, technology and manufacturing DNA, not the corporate capability of a business that is owned by an offshore conglomerate.
"Downer competes with the best international train manufacturers, and we are the only business, local or overseas-owned, that has actually delivered its past couple of projects successfully for state governments."
He said Downer's contract for the Sydney Growth Trains "has a design that is an approved platform that could allow us to go straight into local manufacturing".
The government has budgeted $447 million to upgrade the Tangaras so they can operate for another 12 years, a setback for companies like Downer and UGL which hope to build the replacement fleet.
The fleet has been upgraded several times and is now destined to stay in service until 2036, at which point some of the trains could be almost 50 years old.
The government said on June 5 that the 12-year extension would "ensure passengers have safe and reliable services until the new fleet is constructed and running".
"Upgrading the Tangaras is critical to ensure the government has the time to rebuild this industry from scratch and create a long-term pipeline of manufacturing work," the government said.
"Without life extension works an estimated five Tangaras per year are at risk of breaking down and being pulled from service, greatly impacting commuters."
Mr Minns said before last year's election that Hunter firms would be "extremely competitive" when it came to building the state's next suburban train fleet.
The Goninan workshop made the Tangara trains between 1988 and 1995.
The government has earmarked the Goninan site for housing as part of its Broadmeadow planning strategy, but UGL is understood to have five-year and 10-year options to extend its lease on the privately owned land.
The Cardiff workshop also built the Millennium train fleet in the early 2000s using about 70 per cent local content, including car body manufacturing, fit-out and testing.
A UGL spokesperson said the company was "well positioned to build the next generation of passenger rail fleet in Newcastle, where we proudly built the original Tangara fleet and currently manufacture Australia's only locally made locomotives".
"We've had a presence in the region for more than 125 years, and we look forward to continuing our relationship with the Newcastle community into the future," the spokesperson said.