A computer program called TRUCK has been prepared for the purpose of analyzing the response of Army vehicles to blast waves. The program permits the inclusion of non-linear springs and dampers and allows large rotations, thus making it applicable to the overturning problem. The tire-ground interaction model permits the tire to leave the ground, to recontact the ground, to slide along the ground, and to stop sliding. Spring bottoming is handled as an elastic collision. A shelter mounted on the vehicle and equipment racks within the shelter are permitted to undergo motions relative to the vehicle body.