The Class 378
Capitalstar is a dual-voltage
electric multiple-unit (EMU), designed to be supplied via either the 750
V DC third rail or the
overhead lines. It is a customised version of Bombardier's
Electrostar family, aimed at the short-distance mass-transit end of the market. Following completion of five-car upgrades in 2016, each unit is formed of a driving motor vehicle and an intermediate motor vehicle either side of an intermediate trailer. In Class 378/2 units, the intermediate trailer carries the pantograph and electrical transformer. The interior of the train was designed to maximise passenger capacity. Traditional seating was eliminated and longitudinal seats adopted instead, along with wide areas around the doors to speed the entrance and exit of passengers. Furthermore, a significant portion of each car is intended for use by standing passengers, and thus have grabrails and other holding points for such passengers to steady themselves, broadly similar to a
London Underground tube train. The trains lack toilets, as the whole NLL line takes a little more than one hour to traverse from end to end. In conjunction with the base internal configuration, the cars were outfitted with numerous modern amenities aimed at improving passenger comfort, such as
air conditioning, real-time
passenger information systems, wheelchair accessibility (including the facilitating of level access), and different seat
moquette colours to highlight priority seating. after deployment from the nose door. The spotlight above the headlight cluster on the non-driving side provides illumination for the area at the foot of the steps. To facilitate safe use in the narrow single-bore tunnels on the
East London Line, the units are provided with a
detrainment device at each driver's cab in the form of folding stairs that deploy from the cab's nose door. The train is equipped with sensors to detect how many people are in each coach, and automatically adjust how much energy is expended on heating a particular carriage based upon this capacity, among other intelligent management functions that are performed. External
CCTV is displayed automatically on releasing the doors via an in-cab monitor, removing the need for
Driver-Only Operation (DOO) equipment such as monitors/mirrors at platforms. A somewhat similar arrangement to this had already come into use on
Southern's Electrostar units. Furthermore, in the event of a passenger operating an emergency alarm, the internal CCTV is automatically displayed on the in-cab monitor, allowing the driver to view the affected area of the train, while an
intercom allows the driver to speak to the passenger. == Operations ==