The M1 Tank Driver Trainer (TDT) is an excellent example of how computer-based simulators can provide training that is less expensive, safer, and more flexible than training conducted with operational equipment. The TDT uses computer-generated imagery and a six-degree of freedom motion base to provide training for the driver of the M1 Abrams main battle tank. The TDT facility at Ft. Knox, KY can provide training for 18 drivers simultaneously, all running independent scenarios. The TDT will save millions of dollars over its life cycle. Unfortunately, as with many simulators that depict movement, simulator sickness is a concern because it can potentially degrade training effectiveness and affect the well-being of trainees.

At the request of the U.S. Army Training and Doctrine Command (TRADOC), the U.S. Army Research Institute for the Behavioral and Social Sciences (ARI) conducted research to determine if TDT training was being affected by simulator sickness and, if so, ways to either prevent or alleviate it. ARI collected baseline data on the incidence and severity of symptoms reported by a One Station Unit Training company during their first and some subsequent training sessions. Symptoms were measured using questionnaires, interviews, and a test of balance. For comparison purposes, symptoms were measured following field driving sessions with actual M1 tanks. In addition, Instructor/Operators (I/Os) were interviewed concerning their observations on simulator sickness, and I/O records were tabulated for companies that had previously trained with the simulator. This paper provides background information on simulator sickness, discusses the incidence and severity of symptoms experienced by TDT trainees, changes in symptoms over time, recommendations for alleviating simulator sickness, and how the Ft. Knox User benefitted from those recommendations. In addition, suggestions are presented for simulator sickness research to guide the future design and use of Virtual Environments for training.