Efficient Dredging

Introduction
The concept of Efficient Dredging to which IHC System is dedicated, is a way to describe an ensemble of thinking, processes, hardware, software and services, aimed on assisting dredging contractors to deploy their equipment against the least possible costs and the highest possible benefits in economical and ecological terms as well as in terms of satisfaction for the people who have to work with, and to work on dredgers.

So, in general Efficient Dredging means all those measures and apparatus which aim at reduction of noise, fuel consumption, pollution, over-dredging, wear and tear, maintenance & repair-time, danger and time-losses, while simultaneously smoothening and optimisation production under optimum working conditions for dredgers and crew. All this to be performed in the harsh conditions and environment in which dredgers normally operate.


Now it is common sense that a big deal of those objectives could be fulfilled by sensible and well-organized utilization of dredgers and other equipment – for which dredging contractors are renown. Another part of these aims could be matched by the application of first-class designed dredgers, high-efficiency components and highly wear-resistant equipment – for which our IHC Merwede partners stand day after day. And then yet there remains an area where IHC Systems can specifically apply their Efficient Dredging concept, allowing contractors to provide such well-organized and well-developed, dredgers with additional ‘senses’ and ‘hands & feet’ that throw already superb vessels – or possibly not so superb ones – beyond their own borders.

In this way the concept of Efficient Dredging allows dredging contractors to cope with ever more demanding contracts and ever higher accuracy requirements for dredging jobs. As they want to do these jobs as efficient and as close to the contract as possible, relatively modest investments in instrumentation, automation and surveying techniques bring about dramatic improvement of efficiency and accuracy most times, and are widely accepted to be money well spent.


Tools, solutions and services
From another point of view, the objectives of Efficient Dredging could be realized by the application of a number of ‘tools’ or specific ‘solutions’ and ‘services’ on specific topics within the concept. They are summarized in the right sidebox, together with their main characteristics.

For more information on the concept of Efficient Dredging please read below.

 

Costs versus benefits
Investments in automation can convincingly be substantiated when the generally accepted curve of human performance is considered: human alertness decreases substantially during a working day. Computers however stay fully awake as long as power is switched on. Automation under dredging master supervision can yield improvements of 15 to 25% or even more, depending on local circumstances, and that even without counting a fully integrated systems' vastly easier fault diagnosis and possibilities to reduce wear and fuel consumption. Not to speak about cost reductions obtained by dredging at the right spot only by avoiding dredging at wrong places and over-dredging.

For each project a specific costs/benefits ratio can be worked out to find the optimum level of automation. MTI Holland, IHC Merwede's research institute, has developed a computer model to do this in a matter of seconds. Using the model, various measures have been assessed which reduce the cost per unit of volume of dredged material. The example shows that a relatively modest shortening of dredging time through instrumentation and automation, has a far greater effect in time and money than e.g. a reduction in crew.

 

Specific requirements
Naturally the Efficient Dredging concept requires specific application at each category of dredger:


Besides dredging on the right spot, the total efficiency of the dredging process on hopper dredgers is determined by the efficiency of drag head-cutting process, suction process, hopper loading & sedimentation process and sailing time as well as power limitations. An interesting study on the topic, performed by an IHC Systems crew member was granted a Ph.D.

 

Cutter dredgers, assuming they are dredging on the right spot and with the right profile, can improve efficient dredging by enhancing the efficiency of the cutting and suction process, anchoring efficiency and the pump- and delivery process. Important parameters are swingspeed, skin thickness, delivery pressure, mixture velocity and solids concentration of the mixture. An interesting project on the subject is to be read here.

 

Excavators, bucket line dredgers and backhoes, often applied when dredging needs to be very accurate, need precise monitoring systems, which have been developed to the level of full automatic position control (link follows).

 

 

Instrumentation

IHC Systems' standards for instrumentation fully comply with dredging conditions: temperature and humidity changes, shocks, dust, abrasive materials, pressure variations, mechanical vibration and the humid environment.


Automation

Automation relieves the operator of repetitive, low-intelligence tasks and continuously monitors performance of connected equipment. It provides the operator with all means to exert his core bussiness: transport soil at the lowest price possible.

Standardized automation systems imply attractive delivery, prices and availability of spares. Custom-built systems are totally integrated and fully adapted into the structure of the dredger.


Simulation

The new outside- and underwater view-supported training simulation allows crew to be trained at a realistic platform at costs far below the real thing and without capital intensive consequences of errors. As simulators have all characteristics of modern control systems, operators grow high process awareness and operational insight faster than in daily practice.


Controls for Hydraulic and Electrical Drive Systems

Years of experience with control of hydraulic and electric drive systems and electric power distribution systems guarantee smooth integration and interfacing towards a totally efficient integrated control system. The one man-operated bridge has already proven its benefits on trailing suction hopper dredgers.


Renovation and Retrofitting

IHC System's products could be installed on newly-built as well as on existing dredgers and installations for large efficiency improvements against relatively small investment.


After Sales Services and Customer Support

Field services include installation, commissioning and maintenance worldwide. of own or third-party equipment. In-factory repairs, performed when economic, often include upgrading. Renovation is in fact cost effective maintenance.

Spare parts are vital, as their value multiplies when a job depends on it. Especially rare or obsolete parts or equivalents are to be obtained best through original suppliers. IHC Systems keeps logs on all supplies and parts are kept available as best as can.

Training, advice and documentation services familiarize crew with the equipment at delivery and support crews during operation, which could make the difference between costs and benefits.


Life Cycle Support

A recent branch in assisting contractors in efficiently deploying their fleet – directed at reducing downtime of assets and so serving Efficient Dredging – is the Life Cycle Support strategy of IHC Merwede in which IHC Systems takes its share e.g. in the development of Condition Based Maintenance (CBM), jointly with MTI Holland and IHC Parts & Services.