Two British Rail Class 55 "Deltic" diesel locomotives at King's Cross station in London. The Class 55 "Deltic" locomotives were built by English Electric in 1961 and 1962 and were named after the prototype locomotive, DP1 Deltic. They were designed for high-speed express passenger services, up to 100 mph, on the East Coast Main Line (ECML) between Edinburgh and London King's Cross, and were known for their distinctive "bulldog nose" styling.