Business secretary Vince Cable is at the site of an £82m development that will create hundreds of North East jobs.
The new factory, at Hitachi Rail Europe's plant in Newton Aycliffe, will be built by Darlington-based contractor Shepherd.
The firm will create 150 new jobs to construct the plant and secure hundreds more across the region's supply chain.
Vince Cable and Transport Secretary Patrick McLoughlin will open the development.
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Nigel Farage's former deputy Mr Nuttall says he's the only candidate who can rebuild and unify the party.
The 27-year-old was stabbed in Arthur's Hill, Newcastle on Monday and later died in hospital.
Newcastle get three points from the match and now three points clear at the top.