The same effect is achieved by installing tweendecks that can be hoisted up to lie under the main deck or be lowered on to the tank top.
Isiphumo esifanayo sifunyenwe ngokufaka isithuba phakathi kwimigangatho enokunyuswa phezulu ize ilale ngaphantsi komgangatho ongundoqo okanye yehliselwe ezantsi komphezulu wetanki.