One is Cylinder & Pin type which has the holes on the leg pipe and these holes are engaged by pins

 from the traverses in the jack house. The other is Rack & Pinion gear type Jacking system which has

 the rack gears on the leg pipe in a row.

 Its advantage compared with Cylinder & Pin type is that the pontoon can be lowered or lifted

 continually without any interrupted operation.

   * Cylinder & Pin type

     - The Jacking system of each leg consists of six hydraulic cylinders which by means of pins effect

        the relative motion of the platform in respect of the leg.

    * Rack & Pinion type

     - The jacking system of each leg consists of several numbers of hydraulic operated planetary

         reducers and the rack gears are welded in two rows on the leg pipe.

    * Jacking operation is adopted semi or fully automatic control.