High Quality Content by WIKIPEDIA articles! The Electro-Motive Diesel (EMD) Class 66 (or JT42CWR) is a series of Co-Co six axle diesel locomotives built by EMD for the European heavy freight market. Originally designed for use in Great Britain as the Class 66, a development of the Class 59, they have since been adapted and certified for use in other European countries. Outside Europe, 40 locomotives have been sold to Egyptian Railways for passenger operation.