The two large objects that look a bit like funnels are the counterweights. Perhaps they are intended to look like lilies or ear-trumpets. The movement is controlled by a single hydraulic cylinder and piston. Two more pictures are shown below. Still others have a vertically lifted section.
Transporter bridges have a high gantry from which a movable platform is suspended.
An earlier method is to sling a rope across the river, and to pull a boat across by hand. An ingenious variation is to provide a rudder, with which the boat can be steered at an angle to the current. The boat is linked to the transverse rope by a rope with a pulley at the end, which runs along the transverse rope. The bridge makes a sweeping curve across a bay or estuary, pushed by the flow of the tide or the river. Had the builders tried to make it straight, the tension would have been too great.