Question: What is the name of the designer of the locomotive used on the public rapid transit system serving London and some parts of the adjacent counties of Buckinghamshire, Essex and hertfordshire in the United Kingdom?
Sentence (from "London Underground"): The London Underground (also known simply as the Underground, or by its nickname the Tube) is a public rapid transit system serving London and some parts of the adjacent counties of Buckinghamshire, Essex and Hertfordshire in the United Kingdom.
Relevant evidence: Yes