Most of the premier passenger trains including the AT&SF "Super Chief," various CB&Q "Zephyrs," Great Northern's "Empire Builder," New York Central's "Twentieth Century" and Pennsylvania Railroad's "Broadway Limited" were pulled by EMD "E" unit diesel locomotives from the 1940's to the 1970's. The E3's were introduced in 1939 and became the first "standard" road diesel locomotive that could be ordered off-the-shelf.  The E6's were essentially the same locomotives as the E3's and differed little in appearance.  Broadway Limited is releasing a variety of the shovel-nosed E6's used to pull so many popular passenger trains.  Each model will be equipped with our new Paragon2 DC/DCC Sound & Control system.