Here's something that popped into my head based on posts by Luath and Tom_NUFC in the DBWI thread and an article in this month's Railway Magazine...
A 1960s plan for high-speed rail on the British side of the channel tunnel. Due to budget constraints, however, only the Glasgow/Edinburgh to Dover section was built. The London-Paris section was opened in 1969, with extensions to Birmingham in 1976, Edinburgh in 1980, Glasgow in 1984 and Marseille in 1993. Today, the third-generation "Silver Bullet" does the run in 5 hours and 18 minutes, and construction of a dedicated line from Lille to Berlin is 70% complete. London to Cardiff is also under construction, with 140mph "Javelin" units to operate services between the two cities. However, fares would be more expensive than those on conventional services.
Built in 1948, the CIE 001 class was built to replace steam locomotives on Irish Railways, to the dismay of rail enthusiasts on the emerald isle. Despite concerted efforts to save what they could, steam in Ireland ended in 1960. This led to large numbers of Irish railfans descending on Britain to see steam still at work. In fact, some lines, such as the Settle & Carlisle, continue to employ steam traction. [1]
One of the early successes of the Railway Preservation Society of Ireland was the salvation of the Tralee and Dingle Light Railway in the 1950s, with the help of Ivo Peters and Tom Rolt, the former of whom had photographed the line in 1947 for the
Railway Magazine and the latter of whom had helped save the Talyllyn Railway in Wales. In 2013, the Castlegregory branch was reinstated after a long rebuilding process. [2]
[1] Based on the employment of Class 37s on Cumbrian Coast services OTL.
[2] Based on the OTL histories of the Talyllyn and Welsh Highland Railways.