Aviation fuel
Aviation fuel delivery and stowage systems were extremely vulnerable. The Royal Navy stowed aviation fuel in cylindrical tanks, that in turn were surrounded by seawater. RN aviation fuel lines were purged with carbon dioxide when not in use. The USN used a similar system, which was further improved after the two navies began exchanging information in 1940. Pre-war USN and IJN carrier designs used a fuel stowage system which was not as secure as that used by the RN, but allowed for much greater stowage capacity. Several USN and IJN carriers were lost due to aviation gas fume explosions.