How did they build Bell Rock lighthouse?

Bell Rock was notorious for the danger it posed to ships, as it lies just under the surface of the water for all but a few hours at low tide. In one storm alone during the late 17th century, 70 ships were lost. Also known as Inchcape Rock, Bell Rock received its name after the Abbot from Arbroath tried to install a warning bell during the 14th century. Within a year, the bell was taken by a Dutch pirate. The only method if installing a permanent warning involved the construction of a lighthouse.