VOSTA LMG has delivered, assembled and commissioned a cutter suction dredge to be used for the Potash production in the Dead Sea by her owners Arab Potash Co. Ltd. from Jordan. The design is specific for the harsh corrosive environmental conditions in which the dredge has to operate. This implies the use of specific materials, adequate cooling capacity and cleaning devices for coolers. Due to the location of the Dead Sea, the dredge was transported by sea and land to her final destination. This is why the dredge was made dismountable. The use of digital technology and modular design allowed easy disassembly and assembly.

The dredge is a stationary dredge and equipped with two spuds on the aft side which can be hoisted and lowered in a controlled manner. The bottom part of the spuds are weighted to increase impact during controlled lowering and penetration of the ground. One of the spuds is installed on a spud carrier which is moved by means of a horizontal hydraulic cylinder. The swing is done via two side winches installed on the ladder, under the control cabin. The anchors are placed by two anchor booms, located on the forward pontoons on starboard and port side.

The cutter is driven by a hydraulic motor. For maintenance purposes a cutter platform is provided. The dredge excavates at an average depth of 2 – 3 meters. To optimise the evaporation of water, a deeper dredging depth is not required. To be able to dredge at this shallow depth the draught is kept to a minimum. The dredge pump is located in a separated pump room. The VL 550 dredge pump is made of white iron and equipped with a mechanical seal which does not require fresh or gland water, because it is resistant to the abrasive mixture of water and solids.

Dredge pump drive

The dredge pump is driven by a Caterpillar 16 cylinder V diesel engine type 3516 with 1825 kW continuous power via a reduction gearbox.

Cutter head

The cutter head is a VOSTA type SC 25 which has changeable teeth. The teeth can be changed based on the function required. The assortment allows installation of wide chisels, narrow chisels and pick points.

Main particulars

The dredge “PETRA”, is a type CSD 600S salt mushroom and reef dismountable cutter suction dredger.

Principal Particulars:

Length o.a. (incl. cutter ladder)      72 m

Length over pontoon                    59 m

Beam o.a.                                   12.4 m

Depth  main pontoon                    2.90 m

Dredging capacity:

Suction tube diameter                   600 mm

Discharge tube diameter                600 mm

Cutter power                               600 kW

Cutter speed                               0-30 rpm

Dredge pump engine power            1825 kW

Deck equipment

The ‘PETRA’ is equipped with a number of winches which are essential for her operations:

     -    two side or swing winches for positioning

-          one ladder winch for lifting and lowering the ladder

-          two anchor boom winches to lift the anchors

-          two anchor boom guy winches

-          one cutter platform winch

Electrical Installation

Two generating sets, each capable of providing the electric power required, have been installed. The main electrical functions are handled via a dual redundant PLC system and the monitoring is done via a SCADA system, presented in the wheel house on TFT screens. Furthermore telemetrics have been installed to allow maintenance and guidance access from remote locations. The specific dredge monitoring system installed is integrated in the SCADA system and provides the operator a complete overview of the operations.

The dredge has been produced, assembled and tested to its full extend in Amsterdam. The dredge has been disassembled and transported by heavy lift carrier to Aqaba, Jordan. From port to the Dead Sea the dredge has been transported on heavy carrier trucks. Assembly and Commissioning have taken place at the dredging site.

The design of the dredge allows coupling of its main components in a dry and wet environment, creating the opportunity to launch the equipment in remote locations where the right equipment is.

Within three weeks the dredge has been assembled in the Dead Sea and is now operating in its operational environment.