The lower plate of the keel, called the flat keel plate, forms the centre strake of the outer bottom plating and is frequently fitted in two thicknesses .
Isigqumo esingezantsi sesiqu senqanawa, esibizwa ngokuba sisigqumi sesiqu senqanawa esi sityaba, esenza sesigqumi esingezantsi esingaphandle nesisoloko sifakwe kubungqingqwa obubini.