While researching this article we have heard from dredging contractors around the world that who have been busy naming new and larger dredgers. Although some of these dredgers were ordered before the global economic downturn, dredging contractors are confident that they can find work for them. In February, the largest self-propelled cutter suction dredger built in the Netherlands and one of the largest cutter suction dredgers in the world was named ‘Athena’ at the IHC Merwede shipyard in Kinderdijk, the Netherlands. Dutch dredging contractor Van Oord signed the contract for the design, construction and delivery of the vessel back in September 2008. The vessel will be operational in October 2011 and is equipped with the latest dredging technology, which makes it suitable for working on hard ground and rock down to a depth of more than 32m. The designers paid particular attention to ergonomics and living conditions on board. For example, the entire accommodation section is suspended in order to counteract vibrations. Once it is operational, the Athena will be provided with a Green Passport and a Clean Ship Notation, both from Bureau Veritas. It will be the first dredger in the world to be awarded a Clean Ship Notation. At the end of 2010, Van Oord awarded the contract for the construction of a second powerful, self-propelled cutter suction dredger, Artemis, a sister ship for the Athena.
Damen Dredging Equipment
Another dredger builder is Damen Dredging Equipment, the Netherlands, which reports that it has delivered from stock a CSD500 to Kazachstan. The cutter suction dredger (CSD) has started on its first job, the creation of a new irrigation channel. The standard dredger has been fitted out with several options before leaving the Damen yard. According to Damen the CSD500 is a modular-built dredger which consists of a main pontoon housing the diesel engine and the dredge pump, 2 side pontoons at both port side and starboard side, an ergonomically designed operating cabin, 2 spud poles and the cutter ladder. The pontoons are fitted out with a simple yet heavy duty coupling system enabling rapid and straightforward dismantling and reassembly on land and afloat. All elements have been designed for road, sea and rail transport – very apt as it has been delivered by rail from the Netherlands to its current remote site. The job the new dredger currently is working on is a 14km long irrigation channel, linking an artificial lake to the surrounding farmland. The channel is to be created from scratch and the total job will comprise dredging of some 2 million cubic meters of soil and the dredger will work at its maximum dredging depth of -14m. Before leaving the yard, various options were added to that standard dredger. These include a jib crane for safe handling of the dredge pump and engine room parts, a swivel hose which simplified the dredgers swing movement versus its rigid discharge piping and a rubber ring gate valve in its discharge pipe line. At the end of last year, Damen delivered the CSD ‘Amoris’ to the Port of Antwerp where it will work on the polluted silt treatment plant of SeReAnt. The stationary cutter suction dredger with its 450mm discharge diameter is fitted with 4 spuds of which 2 are placed in spud carriages to ensure a continuous and smooth dredging process. The heavy duty cutter ladder swings by means of hydraulic cylinders, instead of the traditional wide wire winches. The entire dredger including its dredge pumps is electrically driven, while the required total power on-board is 15.75kV at 1.800kVA. The dredge pump capacity for both the cutter action as well as the barge unloader is around 3.000m3/h. The fully automated dredger features for instance dredge pump capacity control, swing ladder control, and automated coupling to the shore-based treatment plant.
Ellicott Dredges
US-based Ellicott Dredges announced the delivery of an 1170 Dragon dredger to dredging contractor Cavache for use on the Kissimmee River Restoration Project. The natural flow of the Everglades is being repaired as part of the Kissimmee River Restoration Project, a partnership between the Army Corps of Engineers and South Florida Water Management District. The main objective of the project is to restore the Everglades ecosystem to its original integrity prior to the floodplain being drained in the 1960s. The dredger is being used to widen the bottom of the canal from 21m to 27m in order to maintain protection against flood damage. The dredger is a crucial component in restoring more than 40 square miles of river-floodplain ecosystem, and is equipped with fully compliant EPA engines, C-32 main and C-9 auxiliary. In addition, the dredger was supplied with bio-degradable hydraulic fluid, which is harmless to the environment if spilled. Ellicott recently designed a fully digital control system featuring PLC-based automation, fingertip controls, data logging capability, and remote control of a booster pump for its customer Alcoa World Alumina Brazil. This system easily allows the dredge operator to view extensive information on the production of the dredger. Also included is a state-of-the-art dredge positioning system, allowing the operator to capture the moves of the dredger in real time. The built-in GPS system and inclinometer provide overall dredge positioning information. The user-friendly interface also incorporates extensive alarms for the dredging system, hydraulic system, and ladder position to ensure all aspects are functioning properly.
IMS Dredge
Ryan Horton, Director of Sales at IMS Dredge, US informed WPD that the Water Resources Department in India has begun using their dredger on an experimental basis to de-silt South Buckingham canal. The de-silting and widening is part of the improvement work being undertaken on the 13km canal stretch
between Okkiyam Madu and Muttukadu under the Jawaharlal Nehru National Urban Renewal Mission (JNNURM) in India. About 200m of the canal near Sholinganallur is being cleaned on a trial basis using machinery from IMS Dredge. Normally, three excavators are used to deepen and de-silt the canal. The machine is used to deepen the canal from the existing three feet to nearly eight feet. A similar dredger has already been used for a project in Neyveli. Once successful, the machine would be used on the entire stretch of the canal. The de-silting work is set to be completed in a few months. The work to widen the canal from the present 20m to 100m will be finished in a year. Simultaneously, six small causeways across the canal would be reconstructed and made into single-lane bridges.
Ravestein BV
Ravestein BV, the Netherlands has announced that it has been awarded a contract by DEME (Dredging, Environmental & Marine Engineering) for the design and construction of a Backhoe Dredger, type Ravestein 900B, at the end of November 2010. The delivery of this turn key project is scheduled on 15 December 2011. The dredger has two fixed spud legs, one hydraulically operated spud carrier with spud leg and an excavator. Each leg can press 340 tonnes and has a holding force of 640 tonnes. They will have a diameter of 1.6mx1.6m. The excavator is a Liebherr P 995 Liptronic type which is specifically designed for a maritime environment.
Watermaster
Watermaster is a versatile environmental dredger especially designed for challenging shallow water environments, such as waterways, small rivers, lakes, ponds, basins and sea shores. In addition to suction dredging and backhoe work, Watermaster can be used for instance for pile driving in water or on-shore lines. Transporting the dredger is easy; it is movable as a complete unit on a standard trailer. When the machine arrives to the site it can unload by itself and “walk” in and out of the water without crane assistance. It ‘cruises’ to the work site using its own propeller system and anchors independently by using its rear legs and front spuds. This means that there is no need for wires, anchors, hydraulic winches, tugboats or service boats for moving or working. These benefits simplified the decision for the City of Sipalay in the Philippines to opt for a Watermaster. In view of continued and worsening problem of flooding and devastation in the City it needed to act by dredging the Sipalay River channel from its mouth up to about a kilometer and a half upstream in order to increase the present capacity of the channel to facilitate more efficient transport of water towards the sea. The dredging component of the project was the biggest challenge because of an instant high capital financial outlay requirement, but the Watermaster came up trumps.To date Watermaster has already logged-in over 11.000 working hours and has dredged vast amount of silt and sand. It is still continually on its maintenance dredging operation in the bay area at the mouth of the river.
IHC Merwede
IHC Merwede, the Netherlands is delighted to announce that alternative fuels have been used in the dredging process for the first time. The company ran a pilot test in which energy derived from hydrogen was the sole source used to power the electrical equipment on board a dredger. The sustainable energy test took place at the Haringvliet estuary in the Netherlands with one of the latest generation of standard cutter suction dredgers: the IHC Beaver 40. Connecting a fuel cell to a dredger had not been tested previously and it needed to operate under the difficult conditions that are typical of the dredging process – vibrations, dust, water, frost and wave motion. The fuel cell successfully powered the dredger for approximately 120 hours. “The pilot test demonstrates that alternative energy sources can be applied to power dredgers,” said Marcel Boor, Manager of Projects & Development at IHC Merwede. The electrical equipment on the current line-up of ships is powered by diesel generators, which results in the emission of harmful substances. The use of fuel cells is emission free, as the hydrogen is converted into heat, electricity and clean water. One of IHC Merwede’s main aims is to construct sustainable vessels. The new IHC Beaver 40 for example has been fitted with LED lighting and the use of high-grade materials means that these ships require less maintenance. IHC Engineering Services, part of IHC Merwede, and Liebherr-France (Mining and Marine Excavators division) also announced that they have entered into a cooperation agreement. Both parties signed a memorandum of understanding (MOU) regarding joint activity in relation to product development, sales and global service of IHC backhoe dredgers. The range of IHC backhoe dredgers comprises stationary dredgers that can be used for a wide range of marine operations fitted with Liebherr excavators and fully adapted for continuous use in maritime environments. The pontoon can be partially lifted out of the water so that the dredger is firmly held in place by the ground. The pontoon is equipped with three spuds for lifting and positioning the IHC backhoe dredger: two fixed spuds are positioned close to the excavator; and the third spud, together with a hydraulically operated spud carrier, is positioned on the opposite side of the dredger. The collaboration between these market-leading partners confirms Liebherr-France’s (Mining and Marine Excavators division) and IHC Merwede’s combined ambition to design and deliver backhoe dredgers for their customers with the lowest cost of ownership. With their respective global presences, both partners offer their customers a worldwide service network.