Read the latest issue of Terra et Aqua featuring articles covering dredging projects as well as the topics of safety, socio-economics, technical innovations and the environment. Individual articles can be read via this page or you can download the complete issue in PDF format.

Articles in this issue

Simulating for sustainability: alternative operating strategies for energy efficiency

In the 2015 Paris agreement, countries committed to implementing measures to reduce greenhouse gas emissions to limit global warming. For the maritime industry specifically, the International Maritime Organization (IMO) has proposed measures for energy efficiency of vessels and candidate measures regarding fuel choice and speed optimisation. This article aims to contribute to the latter by showing how logistical simulations can be used to optimise fleet operations. We will illustrate this in the form of a conceptual case using one cutter and a range of barge fleets. Running simulations with all possible fleets, we will demonstrate the value of extra energy-based alternatives to challenge the fastest, cheapest and most flexible alternatives.

Evaluation of a nature-based agitation dredging solution

The challenge of maintaining harbours and ports while conserving and sustaining coastal habitats, with all the rich resources they provide, requires that port and harbours do more to develop approaches to maintenance dredging that provide benefit to these neighbouring habitats. In this article, we describe an example from Harwich Harbour in the UK where Harwich Haven Authority (the Conservancy Authority) is looking to move to a more nature-based maintenance dredging methodology, using agitation dredging. Using the results of monitoring and sophisticated numerical modelling, we evaluate the likely benefit to the Stour/Orwell intertidal areas arising from the use of the agitation dredging.

Waste heat recovery on dredging vessels

Limiting global warming requires the maritime sector to transition to a more efficient and sustainable operation. Reducing greenhouse gas (GHG) emissions, such as carbon dioxide and methane is vital to limit the global temperature rise (IPCC, 2021). Several legislative initiatives are in effect or are being discussed, including the IMO GHG strategy and the FuelEU Maritime initiative. This article discusses the potential of waste heat recovery (WHR) technologies to reduce the fuel consumption of dredging vessels. Available WHR technologies are compared based on working principle and operational performance for different types and ratings of internal combustion engines.

Published June 2023