The difference with South Wales is TfWs main Depot at Canton is located there, so unit failures can be recovered by other units either on depot or by utilising other units in the area.Are the cancellation % figures really any worse than those in South East Wales?
The Bidston line is unique in that it only really has the 230s planned for it and it's rare to see more than 3-4 of the fleet of 5 available. So there's fewer options to replace them with. On a number of occasions 197s have stepped in at short notice or been pre-planned to cover but they aren't always available to do that.