Introduced in 1981, the Amfleet II (sometimes affectionately called Amtube by enthusiasts due to its distinct, rounded form) was introduced right in the middle of the EMD F40PHs life cycle in Amtrak service. Boasting larger windows and more comfortable seating conditions, the Amfleet II was designed for longer distance travel than its predecessor, the Amfleet I, while still retaining the versatility that its single-level height could provide over its taller, double-decker Superliner brethren.