The rail lines in South Wales will be the latest to come under control of one of Network Rail's Rail Operating Centres. These have already opened in Manchester and York, so far without any reported trouble. The Cardiff ROC is scheduled to open in October 2017 and will eliminate the need for the facility in Port Talbot, as I read this report from Rail Technology magazine (RTM).
This reorganisation would clearly be carried out anyway, as it is part of Network Rail's programme to make job savings. However, re-signalling is also essential to the future electrified running of the Great Western main line (GWML) including that to Neath and Swansea. The RTM report has a slight sting in the tail:
The mammoth GWML electrification project recently reached a major milestone at the end of May when a section of the line was officially declared “energised” for the first time. But the project still faces major challenges, with the ORR [Office of Rail and Road] saying in its annual Network Rail assessment in July that while the infrastructure owner had improved its performance, the GWML electrification scheme remains “at risk”.
The rolling stock share of the programme is running well, however, with Great Western Railway recently ordering seven more Class 800 IEP trains from Hitachi after the first took its maiden voyage at the beginning of July.