Following the privatization of British Railways, Virgin Rail was given the InterCity West Coast franchise, which includes some lines between London and Edinburgh/Glasgow along the West Coast Main Line. Above all, the class 87 and 90 electric locomotives and the older passenger cars were to be replaced. For this purpose, a fast multiple unit was to be developed, which, thanks to tilting technology, should allow higher running speeds in cueves with a high level of passenger comfort at the same time.
The tilting technology comes from Fiat Ferroviaria and allows an inclination of up to eight degrees. In contrast to older systems, it is no longer hydraulic but electromechanical and thus saves maintenance costs. The pantographs are also tilted so that they are always in the correct position in relation to the catenary. The “Tilt Authorization and Speed Supervision” (TASS) system monitors the use of the tilting technology and the permitted speed. Trackside beacons transmit information to the train, for example to suppress tilting in narrow underpasses.
The majority of the trains' engineering comes from Fiat, but final assembly took place at Alstom's Washwood Heath facility. The trains were delivered consisting of eight cars each, but were soon expanded to include another car. The car bodies were mainly made of aluminum, with nose sections made of composite materials, which were nevertheless able to meet the crash standards of the time. A lot of work was put into the design to achieve a visually appealing, aerodynamic shape.
In seven of the nine cars, the inner axle of both bogies is powered. The traction motors are suspended under the frame and transmit their power via a cardan shaft. Although the trains are designed for 140 mph (225 km/h), they could only be approved for 125 mph (201 km/h). This is because the West Coast Main Line could not be upgraded as planned and thus the signaling does not allow for higher speeds.
Between 2001 and 2004 initially 53 sets were completed. Problems that arose caused the decommissioning of the classes 87 and 90 to be delayed. Soon the trains were setting new records on the 401 mile long WCML between London-Euston and Glasgow. The distance southbound was covered in 3 hours and 55 minutes and northbound in two minutes less. Meanwhile, on the non-electrified North Wales Coast Line, they were hauled by a class 57 diesel locomotive. A train was destroyed in a derailment at Grayrigg in 2007 where only one person died due to the structure.
From 2010, a total of 31 trains were lengthened to eleven carriages and then referred to as class 390/1. At the same time, four more were built in Italy, each consisting of eleven cars. When Avanti took over InterCity West in 2019, the Pendolinos went to Avanti West Coast. The trains are being modernized since 2021. A first-class car is exchanged for a second-class one and the interior is modernized and equipped with power sockets.