Planning Committee: National Grid index maps: Overview map sheets Maps of the Isle of Man overlaid with squares showing which National Grid map sheets relate to which area of the Island. When searching the planning application National Grid index maps in S90/3, consult these maps first in order to identify which map sheets you should view depending on which area of the Island you are interested in. There are four maps sheets: national grid 1st set (S90/3/1/1); national grid 2nd set (S90/1/3/2); national grid 3rd set (S90/3/1/3) and a final sheet showing the whole Island numbered with National grid map sheet reference numbers (S90/3/1/4). 1950s-2011