Conversion of the M/V Capt John A. Graham to a side cast dredge
IJmuiden, The Netherlands – MOTAS Dredging Solutions has supplied concept and detailed design services for the dredging installation including hardware.
Brice Civil Constructors is the operator of the dredge, which is currently in operation and doing extensive agitation dredging in the Atchafalaya River near Morgan City in the USA.
The concept was to mount a large dredge pump with two drag arms on the deck of an Offshore Supply Vessel. Rather than pumping material into the hold of a hopper dredge, the vessel would pump the material back overboard. The whole dredging process being assisted by a powerful jetwater system.
The currents in the river will then carry the agitated material further downstream. The whole dredge agitation process is repeated and the river will be opened up and can be maintained at navigational depths for vessels to reach berthing facilities upstream.
The Offshore Supply Vessel “M/V Capt John A. Graham” was selected to be the platform for the whole dredging installation.. The shipyard where the conversion took place was Halimar Shipyard in Morgan City.
We supplied the concept & detailed design services and hardware of the dredging installation.
Together with our partner Hagler Systems, the whole dredging installation was supplied to the shipyard, assembled and installed onboard.
Hardware supplied together with our partner Hagler Systems:
- The dredge pump
- Two dragheads with jetwater provision in the heel and adjustable visor
- The dredge arm
- The Turning glands
- Dredge pipes
- The gantries with several sheave blocks
- The winches
- Hydraulic installation and the Hydraulic Power Pack (HPU)
- The pump inspection piece
Significant cost savings
“We had mechanical challenges we had to overcome” said Brice Civil Constructors, “but we’ve been pumping now for nearly a year. The average volume we’ve pumped on a month-to-month basis is about 5 million cubic yards per month.
The cost savings measured per cubic yard of material pumped are significant compared to cutterhead and hopper rates.
What’s more, the system is working. Since the dredge hit its stride toward the start of the year, the dredge has been exceeding its target and steadily deepening the bar channel to a navigable depth.
Water Injection Dredger for port of Bordeaux successfully launched
MOTAS Global Dredging Solutions completes project in France
IJMUIDEN – For the GIE Dragages Ports, MOTAS Global Dredging Solutions engineered a jetwater installation and delivered key components for a Water Injection Dredger. Recently, this WID has been taken into operation and is being used by the Grand Port Maritime de Bordeaux (member of GIE Dragages Ports), France.
The sea trials of this Water Injection Dredger took place in July this year, after which the WID was handed over to the customer. “A great and challenging project has now been successfully concluded,” says Georges Teheux, General Manager at MOTAS Global Dredging Solutions at the offices of MOTAS in IJmuiden, The Netherlands.
Full package and turnkey delivery
For this project, MOTAS provided an integrated system consisting of the design and the construction of the jet arms, jet pumps, swell compensator, jet beam and hoisting gantry for the Water Injection Dredger. The hydraulic installation, the automation, monitoring and the electric systems were also supplied by MOTAS.
‘A great and challenging project has now been successfully concluded’
Georges Teheux, MOTAS Dredging Solutions
“The largest component of this system is the arm, through which jetwater can be injected into soils at depths up to 22 meters”, says Senior Project Engineer Barend de Wijn. The resulting fluidized sand mixtures than flow down slopes and are eventually carried away by tides and currents.
Challenge
The biggest challenge of the project was the design of the jet arm suspension and the hinges to the vessel. During operation the arm is subjected to dynamic movements of the vessel, upwards and sideways. For example by the swell or an uneven seabed. We have incorporated several passive and active components in the design to absorb these movements, such as an hydraulic swell compensator and others. Another unique element in this design is the jet beam, which can be tilted for optimal fluidization of the soil.
Improvements
For this project, MOTAS made a completely unique design. The installation is autonomous and is interchangeable for other vessels. MOTAS does not merely supply the hardware, but also provides the automation and monitoring.
Specifications of this project
- Several automated dredging modes.
- Jet arms
- Jet beams
- Jetwater pumps
- Jetwater nozzles
- Swell compensator
- Hoisting gantry
- Hydraulic installation
- Electrical systems
- Automation
- Monitoring
Customised Ladder and Underwater Cutting Wheel combination for ROHR-IDRECO
IJmuiden, the Netherlands – MOTAS Dredging Solutions has designed and constructed a customised Ladder plus Underwater Cutting Wheel combination for Rohr-Idreco. On the 5th of November, ROHR-IDRECO successfully launched the electrical dredger.
MOTAS Dredging Solutions designed and constructed the ladder plus Underwater Cutting Wheel (UCW), which will be used by the South American gold mining company. To increase throughput, the mining company required a new tool and a more efficient way of mining.
The integration of the UCW and the ladder into the ROHR-IDRECO dredger was done in close cooperation between the project management and engineering teams.
“The MOTAS Dredging Solutions design weighs 20% less compared to conventional Underwater Cutting Wheel designs”
(Barend de Wijn, MOTAS)
Soil expertise
Engineers at MOTAS Dredging Solutions have extensive knowledge of different excavating processes, required for different types of soil. With this knowledge, MOTAS Dredging Solutions is capable of providing the most suitable and cost-efficient solution for each mining and dredging application.
Hydraulic driven cutting wheel
During the design process of the cutting wheel, Senior Engineer Barend de Wijn noticed a compelling opportunity: “Conventional designs use electric motors and heavy gearboxes to drive the wheel, this new design has a direct drive from a hydraulic motor giving it a lighter, more reliable result”.
With a wheel diameter of 2.5 meters, the specification of the UCW is impressive. Furthermore the cutting knives of the wheel are fabricated from a wear resistant material resulting in reduced downtime. Provided with a 36 meter ladder, the UCW is able to mine at depths of up to 28 meters.
“We offer the entire process. From design and transport to installation and system integration. ”
(Georges Teheux, MOTAS)
The ladder
MOTAS built the entire ladder for this project. In order to maximise competitiveness, MOTAS devised a way to do this as timely and as cost efficient as possible. The ladder was divided into 3 sections and shipped by regular container transport from The UAE to Germany. On arrival it was aligned and welded together. It underwent further quality checks before the final painting was applied. The whole transport took MOTAS under 5 weeks; from our location in the UAE until the arrival at the yard in Wesel, Germany.
Offering turnkey solutions in this way is an important distinction of MOTAS Dredging Solutions.
Specifications for this project
- Underwater Cutting Wheel (UCW)
- A ladder of 36 m long
- A wheel diameter of 2.5 m
- Custom made
- Wear resistant knives
- Direct drive by high torque hydraulic motor
- Low spillage
- Efficient logistics by sea and by road within 5 weeks
- Co-operation with ROHR-IDRECO
APT Global certified with CE Mark for European conformity
APT Global certified with CE Mark for European conformity for its products.
APT Global RMC is certified under European Union regulation as confirming to factory production control.
The APT company was recently certified to European Standards EN 1090-1, APT RMC is now authorized to use the European conformity (CE Mark) on load bearing steel structures it manufactures to EXC3 (Execution class).
APT’s yard activity in its facility are found to be complying with Factory Production Control (FPC) requirements by the auditing body,”
The welding standard ISO 3834-1 is the most demanding standard for evaluating technical and personnel competence in welding performance which gives APT to carve a niche and a strategic advantage in the Oil & Gas Renewables industry.
“This certification is in line with APT’s long time vision of diversifying into offshore /renewables business and adding value to the service extended to existing clients. The organization is always in the forefront of quality along with delivery in line with client’s demand. We look forward to our international clients to award us more contracts in the offshore sector”. Anil Abraham, CEO has noted.
