Sorry I missed the livestream. Really great summary of Irish rail history. I feel it ended one slide too early, and 4-tracking of the line out of Heuston really deserved a photo (even though it got a mention). I think it's the most significant development of the last 20 years (well, 19, it probably ties with the arrival of the ICR stock in 2005). There's some other stuff that's happening but hasn't actually happened yet, so looking forward to future episodes.
Excellent first part of the mini-series. I realise how little I knew about the railways of the island of Ireland. Re DART and 1500V DC, I worked on the electrical equipment for the LHB trains in Preston in 1982 - it was GEC Traction's first production DC Chopper using thyristors and analogue control. The French use 1500V DC extensively for their suburban networks in Paris and Lyon, and most French electric trains are dual voltage 1500V/25kV. The new BEMUs for Irish Rail are being built by Alstom in Katowice (Xtrapolis standard with level boarding), but the bogies will come direct from the bogie factory and be fitted in Ireland.