This group of pages provides an overall commentary on some of the principal routes or those with particular historical significance. Information is drawn from a variety of sources but the Post Office Engineer in Chief’s Annual Reports contain a great amount of detail on the earlier routes in particular. Once the commissioning of new routes became a matter of routine there was, of course, less reason to report in depth.

The pioneering routes such as London to Birmingham and Manchester to Kirk o’Shotts were documented in IEE Proceedings and articles in the Post Office Engineers’ Electrical Journal. Full references will be added to each route in due course, to allow further study if required. I regret that due to copyright restrictions I am unable to make the full texts of these articles available.