First introduced in the late 60s, the ACF 2 Bay Centerflow was designed to carry heavy, dense materials such as sand, concrete and bentonite, unlike larger Centerflow hoppers which are used to transport lighter materials such as grain and plastics. The design proved to be very successful, with thousands being built and production lasting into the 1980s. Examples of the ACF 2 Bay Centerflow can still be found in service today.