Air blast injuries killed the crew of the submarine H.L. Hunley

The submarine H.L. Hunley was the first submarine to sink an enemy ship during combat; however, the cause of its sinking has been a mystery for over 150 years. The Hunley set off a 61.2 kg (135 lb) black powder torpedo at a distance less than 5 m (16 ft) off its bow. Scaled experiments were performed that measured black powder and shock tube explosions underwater and propagation of blasts through a model ship hull. This propagation data was used in combination with archival experimental data to evaluate the risk to the crew from their own torpedo. The blast produced likely caused flexion of the ship hull to transmit the blast wave; the secondary wave transmitted inside the crew compartment was of sufficient magnitude that the calculated chances of survival were less than 16% for each crew member. The submarine drifted to its resting place after the crew died of air blast trauma within the hull.

H.L.亨利号（H.L. Hunley）潜艇是首款在实战中击沉敌方舰船的潜艇，但其沉没原因却成为了跨越150余年的未解之谜。该潜艇曾在距艇艏不足5米（16英尺）的位置，引爆了一枚重达61.2千克（135磅）的黑火药鱼雷。研究人员开展了缩放比例模型实验，对水下黑火药爆炸、激波管爆炸的特性，以及爆炸冲击波在模拟舰体中的传播过程进行了测量。该传播实验数据结合档案留存的实验资料，被用于评估己方鱼雷爆炸对艇员造成的风险。本次爆炸大概率引发舰体屈曲变形，进而传递冲击波；艇员舱室内传播的次生冲击波强度足以造成致命伤害，经计算每名艇员的生存概率均不足16%。艇员因艇内空气冲击创伤身亡后，该潜艇最终漂流至其沉没停泊处。