A research crash simulator is described which is located at the Liberty Mutual Research Center in Hopkinton, Massachusetts. A seven-foot sled is accelerated by compressed air at speeds up to 60 mph, and then decelerated by a combination of aluminum honeycomb and a hydraulic energy absorber. Normally the sled carries an automotive seat, with some type of restraint system, and an anthropometric dummy. Information concerning collision events in the simulator is obtained from electronic transducers and high speed motion pictures. A number of car occupant protection systems have been tested on this simulator, and typical data are presented to illustrate its performance.