The Bordesley train is a 'Parliamentary' to use the jargon, ie. required to comply with an Act of Parliament. There are also however a few trains that call there on Saturdays when Birmingham City play at home - though I'm given to understand that next to nobody uses them.

The proposal in the Network Rail Strategic Business Plan (summarised here by Simon Felton) to start passenger services on the Camp Hill line (between Kings Norton and Moor Street) and the inner part of Tamworth line (which passes Fort Dunlop) would require the closure and/or relocation of Bordesley. This is to accomodate two short new curves (known as chords) from the Camp Hill Line onto the main line into the disused terminal platforms at Moor Street

However, don't get your hopes up. Firstly, this project is at least a decade away from happening. Secondly, the diagram in the business plan shows the possible relocation of Bordesley in between the two chords, which would site it south of the existing station, possibly with the street exit onto Bordesley Middleway.

So there is the official position as it stands. Note that this relocated Bordesley station would still be served by the existing Shirley/Stratford services, not by the new lines.

Now, you could argue that a Custard Factory station could take the place of Bordesley. However, this would just clog up the existing line into Moor Street, which doesn't have the capacity for a service like this, handling as it does fast Chiltern trains plus the London Midland services to Shirley/Stratford. Similar problems would almost certainly occur if you tried to fit a new station into the proposed Camp Hill or Tamworth services, not least because various junctions between Bordesley and Moor Street would be required for operational flexibility on the use of the platforms.

Moreover, the real problem here is that the Custard Factory is simply too close to Moor Street to justify an additional rail station. The Jewellery Quarter station is twice as far from Snow Hill, and Five Ways is about the same distance from New Street. The comparable case in terms of distance is not actually Jewellery Quarter but St Pauls - but that's on the Metro line. Metro services are much more suited (for both technical and timetabling reasons) to short distances between stops.

Sorry to pour cold water on the idea, but I think it's a non-starter - getting BCC to make the walking route from the Bull Ring more appealing would be a much more feasible way ahead.

Is Bordesley Station still operational? There could be a case for closing it down and opening a CF station in its place. There should be room on the viaduct as it used to be four tracks and also housed a cattle station near Adderley Street.