Herakles (pusher) the fuel supply and lubrication system due to the violent pitching of the vessel were not ruled out. On 2 March 2004 the weather in the Bothnian Sea gradually developed into a force 10 storm on the Beaufort scale, with average wind speed around and gusts exceeding . At midnight, shortly before "Herakles-Bulk" sank, the ten-minute average at Svenska Högarn was with three-second gusts of almost . The freezing temperatures combined with strong wind and high waves resulted in fast icing of the ship structures. In 1992 the Finnish Maritime Administration issued a wind limit of for "Herakles" due to
Beaufort scale Beaufort scale The Beaufort scale is an empirical measure that relates wind speed to observed conditions at sea or on land. Its full name is the Beaufort wind force scale. The scale was devised in 1805 by the Irish hydrographer Francis Beaufort (later Rear Admiral Sir Francis Beaufort), a Royal Navy officer, while serving on HMS "Woolwich". The scale that carries Beaufort's name had a long and complex evolution from the previous work of others (including Daniel Defoe the century before) to when Beaufort was Hydrographer of the Navy in the 1830s when it was adopted officially and first used