the class 378 capitalstar is a type of electric multiple unit used on the london overground network. the class is derived from the class 376 trains currently used by southeastern, and are also part of the electrostar family, but featuring significant differences. primarily, the class 378 features fully longitudinal seating similar to that used on london underground rolling stock, which is necessary for the high passenger volume services run on london overground. the units were constructed by bombardier transportation, and were delivered in two separate batches.