CP (Caminhos de ferro Portugueses EP ), the Portuguese State Railway, has modernized two commuter lines in two different networks, both having the same vehicle platform. The new broad-gauge vehicles are in operation in the capital of Lisbon , on the route between the exclusive suburb of Cascals, Lisbon and Azambuja, as well as in the suburbs of the harbour city of Porto in northern Portugal .
Although Lisbon uses 1.5 kV direct-current technology and coaches are built to meet a platform height of 1,080 mm, the suburbs of Porto are served with 25-kV alternating current. In addition, two different platform heights, different from those in Lisbon, have to be accommodated there. Here is an excellent opportunity for project engineers to demonstrate the versatility of modular construction methods.