Network Rail interviews generally test the Non technical skills, and I can't see why this one would be any different. I work in NR Operations and have had numerous interviews throughout the years for various posts and all have followed the same structure:
A few questions about yourself, your history, your suitabilty for the role, why you think you'll be a good fit/what you can bring to the role, your motivation, what you know about the role/company etc.
Then the Non-technical skills questions - generally answer these using STAR based answers - Situation, Task, Action, Result. Look at the NR website for the NTS they focus on and have answers prepared. Questions are like - tell me about a time you've had to work under pressue? How did you cope? What strategies do you use? etc.
Techy questions - I'm used to the Ops side of things so not sure what they'd ask you about asset management. I also suggest you have a read up about NR's safety vision and the tools, processess, and systems in place to promote this.
As I say, I've never been involved in that side of the company so don't know how similar it would be, although I can't imagine it would change too much... But I hope this helps!
