RE: Northern Rail
The Winderemere branch uses Transpennine Express units (class 185's I think) that come from Lancaster / Manchester Airport, go back and forth to Oxenholme a couple of times, then go back to Manchester Airport, so I suspect the only reason the lines being electrified is so TPE can use new electric trains on that route without having to cling on to a couple of diesels just to run that line. Plus Oxenholme to Windermere is a lot shorter train journey than Newcastle to Carlisle!