  the british rail class 166 turbo express is a fleet of diesel multiple units (dmus), originally specified by and built for british rail, the then united kingdom state owned railway operator. they were built by abb at york works between 1992 and 1993. the trains were designed as a faster, air conditioned variant of the class 165 turbo, intended for longer distance services, and, like the 165s, belong to the networker family of trains. they were originally known as networker turbos to distinguish them from the electrically propelled members of that family. the class is still in service, and is operated by first great western on its services out of london paddington station. the trains, along with that operator's class 165 trains, are often known as thames turbos. ==description== these units are a modification of the class 165 design. they have a top speed of  (suitable for mainline use), are carpeted throughout and have air-conditioning. externally, the class 166 can be distinguished from a class 165 by having a first class section at each end of the tr
British_Rail_diesel_multiple_units