What is British Rail Class 387?
{{Infobox train | background = | name = British Rail Class 387<br />''Electrostar'' | image = Reading - GWR 387162 and GTSR 387306.JPG | imagealt = | imagesize = | caption = [[Great Western Railway (train operating company)|Great Western Railway]] Class 387 units at {{stnlnk|Reading}} | interiorimage = GWR Class 387 Interior.jpg | interiorimagealt = | interiorcaption = The interior of a GWR Class 387 unit | service = 8 December 2014{{snd}}present | manufacturer = [[Bombardier Transportation]] | designer = | assembly = | ordernumber = | factory = [[Derby Litchurch Lane Works]] | family = ''[[Bombardier Electrostar|Electrostar]]'' | replaced = {{unbulleted list|{{brc|165}} (GWR)|{{brc|166}} (GWR)|{{brc|317}} (Great Northern)|{{brc|321}} (Great Northern)|{{brc|332}} (Heathrow Express)|{{brc|365}} (Great Northern)|{{brc|442}} (Gatwick Express)}} | yearconstruction = | yearservice = | refurbishment = | yearscrapped = | numberconstruction = | numberbuilt = 107 | numberservice = | numberpreserved = | numberscrapped = | predecessor = | successor = {{ubl|[[British Rail Class 700|Class 700]] ([[Thameslink]])|[[British Rail Class 720|Class 720]] ([[c2c]])}} | formation = {{ubl|4 cars per unit:|{{abbr|DMSO|Driver's cab, Motor car, Standard class, Open saloon}}-{{abbr|MSO|Motor car, Standard class, Open saloon}}-{{abbr|PTSO|Pantograph, Trailer car, Standard class, Open saloon}}-DMSO}} | diagram = | code = | fleetnumbers = | capacity = | operator = {{ubl|Current:|[[Gatwick Express]]|[[Great Western Railway (train operating company)|Great Western Railway]]|[[Govia Thameslink Railway|Great Northern]]|[[Heathrow Express]]|Former:|[[Thameslink]]|[[c2c]]}} | depots = | lines = | carbody = | trainlength = |