Apologies, i thought you were referring to platforms on the existing lines - that said, i still dont see how the cost could be justified.
Chris
Ok, here's what I had in mind.
There would be 6tph from the 3 local platforms, a combination of existing services diverted from New Street and new services.
These would be:
1tph XC to Nottingham, calling: Kingsbury, Tamworth, Burton, Willington, Derby, Long Eaton, Beeston, Nottingham.
1tph XC to Stanstead Airport (calling patten as at present).
1tph XC to Leicester (calling patten as at present, except only calls at Water Orton in peaks and hourly call at South Wigston).
1tph XC to Tamworth, calling: Kingsbury, Wilncote, Tamworth).
2tph LM to Wolverhampton, calling Walmley, Sutton Town, Streetly, Aldridge, Walsall, Pleck, Darlaston James Bridge, Willenhall, Wolverhampton.
My thinking when formulating this idea was to see how local platforms at Curzon Street could be utilised whilst still maintaining some cross-city connectivity on the Cardiff/Worcester-Tamworth/Nuneaton axis as suggested in the West Midlands RUS. The hourly Cardiff - Nottingham service would continue to run through New Street, and so would a new hourly Worcester - Coventry service.
This would provide 2tph from Worcester to New Street and would give Coleshill and Nuneaton 3tph to Birmingham (as well as an hourly service at Water Orton and a direct hourly service to university) as well as a direct Birmingham service for Bedworth and the new stations on the Coventry - Nuneaton line.
I've added an extra 1tph to Tamworth as the RUS suggests, but this terminates at Curzon Street instead of going cross city. My thinking for this is that Tamworth already has an hourly service to Univeirsty, so if the other cross city service per hour went to Coleshill and Nuneaton, it would give those stations an hourly university service too.
I've mentioned the new station at Kingsbury, but not at Fort Parkway, as having looked at the detailed maps for HS2 in the area, a don't think enough land will be available for the construction of a station.
My reasoning for the Sutton Park line passenger service is based on very rough journey time calculations. Under the proposed Birmingham - Walsall - Aldridge service, a Birmingham - Aldridge journey would take 36 minutes, but a DMU service going via Sutton could get from Aldridge to central Birmingham in just 29 minutes (36 minutes from Walsall). This is based on the rough assumption of a 14 minute journey time from Curzon Street to Walmley, 5 minutes Walmley to Sutton Town, 5 minutes Sutton Town to Streetly, 5 minutes Streetly to Aldridge and 7 minutes Aldridge to Walsall.
I believe this would be more cost effective than building a terminus station at Aldridge and electrification for a Birmingham service via Walsall and would provide a rail service for other parts of north Birmingham as well as a usefull Sutton - Walsall service.
Now the paths that have been freed at New Street would allow for a 3tph service to operate on the Camp Hill Line to King's Norton, meaning that the Bordesley Cord would not be needed. I've calculated them to depart New Street at xx18, xx39 & xx57 once minor re timings to other services have been taken into account. That does of course depend upon freight traffic being removed from the Camp Hill line onto the re-opened South Staffordshire line (Stourbridge - Walsall) and assuming that the Sutton Park line will be able to handle additional freight traffic and a 2tph passenger service. It will probably require re signaling of the line from Saltley to Water Orton and the re-doubling of the cords at the eastern end of the Sutton Park Line.
I believe the Sutton Park service should extend onto Wolverhampton with local stations at Pleck, Darlaston James Bridge and Willenhall as a cheaper alternative to extending the Midland Metro to Walsall.
And the central Birmingham HS2 station needs to be called Birmingham Eastside, not Birmingham Curzon Street, to refer to the more general part of the city in which it will be located.
