Electrostar train - cramped seating , originally uploaded by Henry░Law . Electrostars, the EMU originally developed by AdTranz before it was taken over by Bombardier, are a mixed bunch. The first entered service around 2000 and comprise classes 357, 375, 376, 377, 378 and 379. Originally they were quite unreliable but they are now in the same league as the EPB units which they replaced, dating from the 1960s. Variations include alternative seating layouts, sliding or plug doors, full width cabs or half-cabs with gangways (top picture), and AC, DC or dual voltage types. Probably the most successful version is the class 378 for London Overground (second picture), which has sliding doors and longitudinal seating, an ideal layout for the type of service for which they are used. Some versions are very comfortable, for example the end cars in the units operating on the Southern main lines (third picture) have 2+2 seating with tables, all aligned to the windows. Much less satisfactory are the...