The modeling of fire and smoke spread is an evolvingfield. As knowledge is acquired and resources become available, models are enhanced to make their predictions more accurate and/or their computations faster. This paper will discuss the Consolidated Fire and Smoke Transport (CFAST) zone fire model, developed by the National Institute of Standards and Technology (NIST), and a recent addition to that model, referred to as the Corridor Flow Submodel. The goal of this new submodel is to more accurately predict the flow of smoke down a corridor which has an impact on fire protection issues such as detection and escape time. Prior to the addition of this new submodel, CFAST assumed that smoke traveled instantly from one side of a compartment to another. Development of the submodel will be discussed and then the enhanced CFAST, Version 4.0.1 (executable dated 3/8/00), will be used to model a real-scale experiment conducted onboard the ex-USS SHADWELL, the Navy's R&D Damage Control platform.