Braxton-Smith said the new cost included $175 million for 12 new three-car electric trains.
He defended the cost blowout, telling the committee the $615 million price tag announced by the former Labor Government “could hardly be taken as a lifetime comparison”.
“You have to bear in mind that when it was originally procured, the electrification was procured only through to Salisbury and without any electric trains,” he said.
“Any other previous budget was not based on what you would call a reliable cost estimate.”
The State Government this morning announced the project would now not be competed until April, with a full shutdown of the state’s train network also required for two days next month.
Transport Minister Corey Wingard said the Gawler line would reopen in April following the completion of commissioning activities of the signalling system.
The train line, which services the northern suburbs around Playford and Salisbury, has been closed for electrification works since December 2020.
The project was first announced in 2008 by the Rann Government.
The Marshall Government attributed the latest delays to border restrictions making it difficult to access skilled workers interstate.
Wingard, who last year stated the project would be completed in late 2021 or early 2022, apologised for the “further short delay” but said the State Government was doing “all that we can” to get the line running again.
The transport minister also announced that the final stage of works will necessitate “impacts” to “the entire Adelaide Metro Network during the period 18-21 February, with all lines closed on 19 and 20 February”.
Opposition transport spokesman Tom Koutsantonis labelled the latest delay “sheer incompetence”.
“Long suffering residents of the northern suburbs have been without a train line for more than a year and still don’t know the exact date of when services will resume,” he said.
Asked when full services would resume on the Gawler line, Braxton-Smith said the department was “yet to finalise the precise date” because of “uncertainties”.
“But we have a target of the last week of April so it is late April when we expect to commence revenuexjmtzyw services and have a timetable,” he said.
“That’s still to be determined. That will be a function of the progress of the project in the intervening period and how quickly we can get the training done of the drivers that are necessary in order to run a timetable.
“So introduction of services available to the public is last week of April and the final setting of the initial timetable will be done, I would say, in the last four weeks having taken account of the extent to which there are impacts on train driver availability by virtue of COVID-19 outbreak and the ability to sustain revenue services on the remainder of the network and drive test trains and train the remaining drivers.
“So it is foreseeable that there may be a staged introduction of services if we are further impacted by COVID outbreaks.”
Braxton-Smith told the committee there were issues with the original design and construct contract entered into by the previous government in 2018.
“The contract that was executed included incomplete schedules for scope and standards that had not been agreed with the contractor,” he said.
“It had been tendered in mid-2017 with only a high level concept design several years old rather than the fully developed reference design and a detailed specification to a standard customarily used for a design and construct contract.
“This subsequently gave rise to delays in finalising an agreed specification and scope and approved design for construction and an achievable delivery program.”
Braxton-Smith said the project budget was “reset” in late 2020 to $715 million “with an increase of $100 million in total which includes $175 million for 12 new electric trains that were ordered in June 2019”.
Braxton-Smith said work has progressed on the upgrade “however further challenges arose in the course of 2021”.
“In addition to adverse weather and latent ground conditions, most significantly there was a liquidation of a major component supplier – SA Structural Steel – and the impacts of the COVID-19 outbreak and the management response to it across the state and in other states,” he said.