Politicians are often only focused on the current election cycle.
The diesel railcars can seat 40-65 people per carriage, perhaps up to twice that standing. The 2700s are currently being withdrawn as they are the least reliable. So likely minimum train size is two carriages. http://www.irishrail.ie/index.jsp?p=123&n=210
Roughan & O’Donovan / AECOM http://www.roughanodonovan.com/proje...-Rail-line.asp
have the documentation substantially progressed.
Depending on external factors, primarily the economy, it might be worthwhile. In the recession, the high cost of borrowing and with the M3 in place it is unlikely to be worthwhile.
If someone has €300-500 million, things can move forward.
In the current environment, the best that can be hoped for is improving existing lines - signalling, level crossings, stations, etc.