Alcázar de San Juan Rail Collision in Spain

On December 20, 1973, a serious accident occurred near Alcázar de San Juan in Castilla-La Mancha, a critical junction in the RENFE network. Two trains—one a passenger service and the other a freight consist—collided after a signaling error led to conflicting movements on the same track. The impact caused multiple coach derailments and resulted in nine deaths and dozens of injuries. Emergency services and RENFE crews worked through the night to rescue passengers and clear the wreckage. The accident prompted internal reviews of signaling procedures and crew communication protocols across the Spanish state railway. Although smaller in scale than later Spanish rail disasters, the Alcázar de San Juan collision played an important role in accelerating RENFE’s modernization of block signaling and dispatch coordination during the 1970s.