Over nearly 50 years of publication, Terra et Aqua has benchmarked innovative maritime solutions through more than 150 issues. Articles are available here as well as in IADC’s Knowledge Centre.

“Dilution”, A New Technology Used at the Pearl River Estuary Pipeline Installation Project, Management of Contaminated Mud in Hong Kong, The Sweep Dredge: High Accuracy Dredging Trials Continue, New Developments in Environmental Dredging: From Scoop to Sweep Dredge
65
Published December 1996

Terra et Aqua 65 – complete issue

Read the complete issue containing articles, upcoming events, an interview and book review.

New Developments in Environmental Dredging: From Scoop to Sweep Dredge

Authors: Stefaan Vandycke

The winner of the 1996 IADC Award, this paper describes one of the recent dredging techniques tested on the Ketelmeer and now being used in the Port of Nieuwpoort, Belgium.

The Sweep Dredge: High Accuracy Dredging Trials Continue

Authors: T. Arts

More techniques for dredging thin layers in contaminated waters have been tested on the Ketelmeer in 1996. A summary.

Management of Contaminated Mud in Hong Kong

Special pits dredged beneath the seabed and then capped with clean sand and mud are proving a solution to dredging contaminated waters in Hong Kong.

“Dilution”, A New Technology Used at the Pearl River Estuary Pipeline Installation Project

Authors: Noël Pille

Unable to excavate a conventional open trench because of dumping limitations, a new technique was developed to install the pipeline through “diluted” soil.

Calculation of Sand Losses During Hopper Loading Process in Trailers, Turbidity Caused by Dredging; Viewed in Perspective, Assessment of Offshore Sand and Gravel for Dredging
64
Published September 1996

Terra et Aqua 64 – complete issue

Read the complete issue containing articles, upcoming events, an interview and book review.

Assessment of Offshore Sand and Gravel for Dredging

Authors: Ian Selby | Klaas Ooms

Offshore sand and gravel at depths of -60 metres form an important economic resource. Accurate assessment of these offshore deposits are important to prevent environmental problems, conflicts and delays.

Turbidity Caused by Dredging; Viewed in Perspective

The environmental impact of turbidity depends upon the dredging technique used; the ease with which the sea bed material becomes resuspended; and the condition of the surface water. An on-site analysis is advisable.

Calculation of Sand Losses During Hopper Loading Process in Trailers

The process that takes place in the sedimentation tanks of water treatment plants is similar to the hopper loading process and can provide a theoretical model for trailing suction hopper dredgers.

The Role of Education and Training in Dredging, A Training Simulator for Cutter Suction Dredgers: Bridging the Gap between Theory and Practice, Construction of a Pilot Project Island in IJ-meer, The Human Factor
63
Published June 1996

Terra et Aqua 63 – complete issue

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The Human Factor

Authors: Walter Moret

High-tech dredging companies are thinking as much about investing in “human capital” as they do in materials and equipment.

Construction of a Pilot Project Island in IJmeer

To create new land new techniques have been developed for the placement of sand in thin layers. They have proven both incredibly accurate and economical.

A Training Simulator for Cutter Suction Dredgers: Bridging the Gap between Theory and Practice

Computer simulations are becoming a significant, controllable and safe way of getting theoretical knowledge out of the “labs” and onto the dredge sites.

The Role of Education and Training in Dredging

Authors: John Riddell

At the WODCON XIV, ten panelists from various educational institutions and the dredging industry discussed the need for improved training opportunities.

Solids Transportation in a Long Pipeline Connected with a Dredge, Sydney Airport's Parallel Runway: The Beneficial Use of Sand Dredged in Botany Bay, An Evaluation of the Behaviour of Pollutants During Dredging Activities
62
Published March 1996

Terra et Aqua 62 – complete issue

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An Evaluation of the Behaviour of Pollutants During Dredging Activities

Two main classes of pollutants, heavy metals and organic micropollutants, are evaluated to determine the extent of environmental risks when dredging and how these can be controlled.

Sydney Airport’s Parallel Runway: The Beneficial Use of Sand Dredged in Botany Bay

Alternative sources of bulk filling for the runway were considered, but dredging sand in Botany Bay was the most cost-efficient and environmentally sound.

Solids Transportation in a Long Pipeline Connected with a Dredge

Authors: Vaclav Matousek

Prediction of the aggregation process and an accurate estimate of the critical velocity in a pipeline may lead to more effective control of the diesel engines and other types of drives.

High Accuracy Sanitation Dredging Trials, The Roman Harbour of Velsen, Beneficial Use of Dredged Material from the Firth of Clyde
61
Published December 1995

Terra et Aqua 61 – complete issue

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Beneficial Use of Dredged Material from the Firth of Clyde

Authors: Martin J. Allen

Research has proven that most material dredged from Scotland’s Firth of Clyde is clean. By dumping it at sea, port authorities are missing the opportunity to use this clean dredged material for beach nourishment and coastal erosion prevention.

The Roman Harbour of Velsen

Authors: Pauline van Rijn

The Dutch pride themselves on their dredging history and technology, but archeologists have proven that the Romans dredged the Lowlands first.

High Accuracy Sanitation Dredging Trials

Private dredging companies and government have joined forces to develop environmentally sound techniques for dredging thin layers in the highly contaminated Lake Ketelmeer, The Netherlands.

The Wear Sensitive Cutting Principle of a Cutter Suction Dredger, Privatisation of Ports in New Zealand, Besòs Long Sea Outfall, Barcelona, A Tale of Two Dredgers
60
Published September 1995

Terra et Aqua 60 – complete issue

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A Tale of Two Dredgers

Authors: Adrian Hunt

A look at the joys of working for a high-tech private dredging company versus the difficulties of an underfunded state-run organisation.

Besòs Long Sea Outfall, Barcelona

To satisfy EC bathing water quality directives, a new, longer outfall was needed. Dredgers had to reckon with the recreational importance of Spain’s beaches, plus the existence of an operative gas pipeline.

Privatisation of Ports in New Zealand

Authors: Heini Evers | Roy Weaver

By shifting from port-operated dredging to privatised contract dredging, three New Zealand ports have moved from world-ranked laggards to the top echelon of international ports in terms of profitability and performance.

The Wear Sensitive Cutting Principle of a Cutter Suction Dredger

Authors: Jan Reinout Deketh

Laboratory experiments demonstrate from a wear point of view the inefficiency of cutting tools on a cutter suction dredger. Recommendations are made to optimise the cutterhead design and cutting process.

59
Published June 1995

Terra et Aqua 59 – complete issue

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Reclamation and Restructuring of Santa Gilla Lagoon

Authors: Daniele Defendi

A stagnated lake is rescued from an ecological disaster by a system of underwater and circumference canals which keep the waters circulating.