KiwiRail expects new recruits to be sourced from the Dunedin area, with extensive training on offer as staff numbers swell from 23 to about 100.
The Government announced last week it was dedicating $19.97million of provincial growth funding to re-establish the workshop as a mechanical hub and heavy engineering facility to service KiwiRail's trains.
Most work at Hillside ended in 2012, after KiwiRail awarded an estimated $29million manufacturing contract to a Chinese company, in what was seen at the time as a terminal blow to the workshops.
The new investment meant KiwiRail would be able to earthquake-proof ageing buildings, get rid of asbestos, overhaul equipment at the site and more.
It will become a multipurpose workshop that can ramp up its maintenance and upgrades of rolling stock and possibly fit out passenger cars, as has been done in the past.
Asked if Dunedin had the skills available to fill the 40 extra jobs expected to be required in the next three years, and about 25 more in the ensuing years, Rail & Maritime Transport Union (RMTU) South Island organiser John Kerr said there were challenges.
"Skilled tradesmen are difficult to get hold of, there's no question about that."
When Hillside was "run down" prior to its 2012 closure, a lot of the pool of talent left the city.
However, quite a few tradespeople left Cadbury after its closure last year, and some were still around.
Mr Kerr said KiwiRail was committed to "bringing in new blood" and was a very good employer in terms of training.
KiwiRail had recognised one of its biggest risks was a demographic bulge of older, mostly male workers, who were going to be retiring.
Recruitment and training programmes had been put in place to deal with that, and the RMTU had worked with the company on the issue.
Mr Kerr said there would be former Cadbury staff with the necessary skills to move to Hillside.
A few had already moved to Dunedin Railways.
While there were "nuances" differentiating work in a factory from work on trains, the likes of fitters, for instance, would be able to adapt to the new workplace fairly easily, as would boilermakers, Mr Kerr said.
The combination of talent that was about, and that both the company and the union were committed to training people, meant the new jobs could be filled.
KiwiRail chief operating officer David Gordon said the company would first be working to upgrade the two main workshops and establish new facilities to undertake other types of maintenance work.
"We will be staging this work to minimise any disruption on the existing activities at Hillside.
"Once that is done we can expand operations and take on additional staff."
At least 10% of the new staff would be apprentices.
"We expect that a number of the new recruits will come from Dunedin and that clearly there will need to be extensive training for some."
