The optimal control of an offshore operation is analysed: a hideck which is at rest on a barge is lifted from the barge by means of a partly submerged frame that receives buoyancy by pumping water out of three cylinders connected to the frame. Air is pumped into the cylinders in order to maintain a positive difference between the internal air-pressure and the external water-pressure: ... https://allfixelectricales.shop/product-category/dryer-drum-support-bush/