Damen has built more than 20 DOP dredgers on a one-off basis and at least 380 DOP pumps. The DOP submersible dredge pump has been such a great success over the last 25 years because of its simple concept, which is based on a well-proven dredge pump, directly driven by a hydraulic or electric motor, assembled in a rigid housing with the ability to attach all kinds of specialised suction devices, such as mining heads or cutter units. Moreover, the DOP can easily be connected to excavators, cranes, etc.
Olivier Marcus, Damen Product Director Dredging, explains: “In the past we have had many requests for ‘ad hoc’ dredgers using a DOP pump. So we have listened to our clients and learnt from that. They told us mobility and a deep, dredging depth were vital. The knowledge and experience we have gained over the years has now led to the development of a new standard series of DOP Dredgers focusing on maximum sand production at significant depths and practical transport and assembly due to the limited unit weights.”
Dams, mining and sand winning
In recent years there has been more demand for specialised dredgers from hydroelectric dam/water reservoir operators, sand mining companies, and dredging companies carrying out sand winning for reclamation projects, he adds. “There are probably tens of thousands of hydropower dams and water reservoirs in the world built in the last decades. As the flow of the river is dramatically reduced, the sediment it carries settles by the dam. The DOP dredger is ideal to tackle dam maintenance work.”
DOP dredgers are also very good for deep sand winning. “Mining companies are going deeper and deeper for minerals. And separately, there is a lot more land reclamation taking place. The DOP dredger, with the submerged DOP pump, can go much deeper to win sand when compared to a Cutter Suction Dredger.”
Depths to 100 m
The new Damen DOP Dredger Series makes use of the standard DOP 150, 200, 250 and 350, which have a mixture capacity ranging from 600m3/h to 2,400 m3/h. Due to the use of a submerged dredge pump, the DOP Dredger is simply able to reach depths other dredgers cannot, with an ability to dredge to 100 m. Damen is also introducing an all-electric version of the DOP Dredger, which is particularly appealing for maintenance dredging at hydroelectric dams.
Often projects are taking place in very remote areas, Mr Marcus adds, in the case of hydroelectric dams, high up in the mountains where road access is not easy. Here, the DOP Dredger is ideal because it is easily dismountable and transportable because even its largest components are never bigger than a standard container size. It also has a limited weight, so can be assembled with a small crane.
Quick delivery times
The Damen DOP Dredger Series can be delivered at very short notice. The DOP pumps, power packs and pontoons are standard and therefore in stock. “We can have a fully built up dredger ready for the customer within a few weeks or if customers prefer, it can be built on-site or at a location of their choice.”
It is also possible to change the suction head depending on the project, giving a lot of flexibility, he points out. For example for compact material, a cutter can be installed, or a water injection head to boost production in free flowing sand.
Mr Marcus concludes: “The DOP Dredger client benefits from Damen’s standardised products, which offer a well proven design and provide guaranteed performance, and on top of that the dredgers can be delivered promptly to the customer, no matter how remote they are.”
For more information please look at www.damen.com.