The first Inland Rail works around Forbes could go out to tender within 12 months.

Project director for the Stockinbingal to Parkes section of the project, Melvyn Maylin, gave an update to Forbes Shire Council at the December meeting.

He said the team is progressing with plans to fix the "pinch points" on the 173km of rain line between Stockinbingal and Parkes so that it will be able to take trains with double-stacked containers.

Close to Forbes, that includes introducing a 2.2km loop at Daroobalgie and lowering the track under the bridge at Wyndham Avenue to give the required 7.1m clearance.

They're still working on the best solution for the bridge over the Lachlan River in Bathurst Street, which was opened in 1914.

"Remembering that we need to get another 1.5 metres, you can't get through under those cross members on the top of the truss," Mr Maylin explained.

Options include modifying the existing truss, replacing the existing truss, or building a new bridge. Working out which of those options is best is one of the tasks for contractor WSP.

"It's quite an interesting challenging site, it's a relatively small project but because of the incised river and the location ... we have done some flood modelling though and we believe we have a solution that will work," Mr Maylin said.

The track will also need to be "slid" sideways in a few locations - including the historic Forbes railway station - to give the required horizontal clearance.

The Stockinbingal to Parkes section of the Inland Rail is currently in the "reference design" phase, with planning approval next. From there, they will be developing detailed designs that can go out to a construction contract.

"We've got a little work to do in terms of finalising solutions and seeking approvals before we go to physical works but I have a program which sees that happen mid to late next year," Mr Maylin said.

The coming months will see the team working with the council and local groups including heritage, there are community consultation sessions this week so those interested can get an update on the project.

Online events are on Tuesday at 12.30pm and Wednesday at 7pm, to find out more about those go online to inlandrail.artc.com.au/events

You can also meet the team at Club Forbes this Friday or Saturday.

Drop-in sessions are on from 6pm to 8pm on December 4, and from 9am to 11am on December 5.

Early next year there will be supplier briefings to help businesses identify the opportunities ahead.

Construction could begin in the first quarter of 2022, and continue through to the final quarter of 2023.