A Russian bucket dredger which would occasionally dredge the channel did not appear on a reliable basis.

Dragon Oil already owned a pontoon with a crane and proposed that its crew would also operate the new dredger, but as they had little dredging experience DDE sent a consultant to precisely determine their needs. This resulted in a design for a 30m long dismountable pontoon with a DOP2320 submersible dredge pump working with a swell compensator. The pontoon was designed to be positioned in the wave direction so that it would always rest on the tops of two waves, thus moving vertically only, with dredging unhampered by rolling on the waves.

The DOP submersible dredge pump is suspended on a hoisting wire running over a swell compensator. In this flexible configuration, the jetwater assisted dredge pump easily removes the fine sand and silt from the channel.

The dredger is equipped with four 6 ton winches for secure mooring in heavy seas and its own 10kVA genset allows continuous round the clock operation. The dredge pump, winches and jetwater pump are hydraulically driven by a 314kW Scania power pack mounted on the deck, with the 200m 3/h, jetwater pump feeding the suction head.

The dredger is built of standard containerised pontoons joined by a simple and proven coupling system. These shortened delivery time as they could be transported by rail. Other dredging components such as the DOP pump, gantry, winches and operating cabin are also stock items which fit in standard transport containers to further minimise delivery times.

Upon arrival in Turkmenistan, the dredger and its 500m floating pipeline were assembled by its crew and a Damen field service engineer within two weeks. The crew was trained for another two weeks and the DOP plain suction dredger is already performing beyond expectations, achieving continuous high production in the perpetual swell.

MJ Information No: 20503