Industrial control systems employ a variety of hardware, software and network protocols to control physical processes that are critical to societal functions. It is vital that industrial control system operators receive quality training to defend against cyber attacks. Hands-on training exercises with real-world control systems enable operators to learn defensive techniques and understand the real-world impacts of their control decisions. However, cyber attacks and operator actions have unforeseen effects that can take a significant amount of time to manifest and potentially cause physical harm to systems, making high-fidelity training exercises costly and time-consuming.This chapter presents a methodology for accelerating training exercises by simulating and predicting the effects of cyber events in partially-simulated control systems. A hardware-in-the-loop simulation comprising a software-modeled water tank and a commercially-available programmable logic controller are used to demonstrate the feasibility of the methodology. The experimental results demonstrate that the effects of cyber events can be accurately simulated at speeds faster than real time, significantly enhancing operator training regimens.