The Rail, Tram and Bus Union wants the NSW Premier to stop the state's new intercity trains from entering service after a review of the $2 billion fleet's operating model flagged safety concerns.
RTBU state secretary Alex Claassens said the report, which the union commissioned last year, confirmed "the long-held concern" of rail workers "that the [New Intercity Fleet] is a safety disaster waiting to happen".
The report, titled Independent Safety Evaluation of the New Intercity Fleet and by Klaus Clemens Engineers, described the model as "not safe so far as is reasonably practical" because "all material hazards" had not been identified nor assessed "to the degree necessary".
"Particular concerns are raised with the CCTV view being obstructed by the open saloon door, shortcomings with the CCTV technology and the lack of monitoring of the platform gap," it says.
The South Korean-made trains are designed to operate without a guard, with drivers using CCTV to monitor the train's passenger doors.
Guards will no longer monitor the gap between the train and platform at stations under changes to their role.
"The limitations of the CCTV technology have not been documented, assessed and tested to demonstrate that those limitations will provide a fit-for-purpose replacement to the eyes and ears of the guard and [right of way] staff," the report says.
The first of the 55-trains ordered have been in testing and are due to enter service on the Central Coast-Newcastle line next month.
Mr Claassens said he had written to the premier warning her that the proposed operating system was "unsafe" and that the government "must not allow" the trains to enter service until the "dangerous" model was "fixed" and the fleet "proven safe".
"The design of this train risks commuters falling through the gap between the train and platform, resulting in injury or death," he said. "I can't stress enough that public protection must be the first priority. Trains must not hit service until passenger safety is guaranteed."
The release of the union-commissioned report comes close to a year after the government released the findings of a review it ordered into the operating model.
It concluded the model was "safer than comparable rail operations around the world" and the procedures had been "applied internationally for many years with acceptable levels of safety".
A Transport for NSW spokesman said on Friday that the agency was reviewing the union-commissioned report and its findings would be "taken seriously".
"The CCTV technology will provide the driver and the customer service guard with a clear view of the entire platform in all conditions and platform configurations," he said.
"The train is also equipped with sensitive door edges meaning doors will re-open automatically when an object is detected, and the train will not be able to move unless all of the doors are closed."