This work investigates crew opinions about manual intervention on board submarines and planned new solutions on the new submarine, the A26. The planned solutions include an unmanned aft and the installation of water mist instead of Halon 1301 as fire suppression system. Literature, survey and interviews were used to gather information. The crew routines and previous fire incidents were determined. The survey shows that many crew members have not experienced fire on board and that in many cases they start a manual intervention later than as prescribed in the regulations. Interviews and survey show that the crew is sceptical towards the planned changes but that information could change this. This work has contributed to the design and construction of the next Swedish submarine, the A26.