The City of Liverpool is served by Merseyrail, a suburban rail network unique in many ways and subdivided into two main routes: The Northern Line and the Wirral Line. We travel over the latter on board third rail class 507 and 508 electric multiple units. While the Northern Line serves the Liverpool side of the Mersey, the Wirral Line runs beneath the wide river separating Liverpool from Birkenhead and the Wirral Peninsula. The Wirral Line consists of two main routes with four branches covering a route mileage of 33 miles. We see all four branches from the Driver's cab in virtual real time: Highlights include the 19th century river tunnel with its 1 in 27 gradients which we see in both directions along with the 20th century single loop line. The majority of the Wirral Line is signalled from the IECC signalling centre at Sandhills and Video 125 cameras were there to follow our trains from a signallers point of view.