Focusing on Dredging Optimization

HR Wallingford – the company that provided site supervision on some of the world’s largest dredging projects, including DP World’s London Gateway Port development project and the Ichthys, Gladstone and Wheatstone LNG projects in Australia – today released an interesting article on dredging optimization.

“Since dredging often represents a significant portion of the opex and capex costs associated with maritime infrastructure, dredging optimization is something that owners, operators and developers increasingly need to focus on,” said Mark Lee, HR Wallingford’s Dredging Group Manager.

“In simple terms, optimization is about identifying, quantifying and implementing efficiency savings. Dredging is a key target for optimization because of its significance as a cost and its highly technical nature, which can make it difficult for those managing the operation of infrastructure or its construction to see efficiency gains clearly,” added Mark Lee.

What’s more, optimization often results in additional benefits such as reduced environmental impacts as a consequence of less dredging or more effective dredging. This means it is also of interest to regulators, fisheries representatives and local residents and not just the project owner.

The opportunity to optimize dredging can be identified at any stage of a project’s cycle, for example:

• At the design stage. By examining the navigational and operational requirement of the facility in order to minimize the dredging requirement. This can reduce costs and the impact footprint of the project.
• On tendering and construction. Determining the most appropriate and efficient dredging method by assessing the dredging plant type and capability, and preparing a dredging contract package tailored to the project’s specific needs. This can lead to a reduction in overall project costs, as well as ensuring compliance with any imposed regulatory conditions whilst attracting competitive bids.
• During operation. By determining the most efficient maintenance dredging strategy with respect to the project’s commercial need and timings. For example, can the area requiring dredging be reduced? Can the dredging be done better/cheaper? As well as reducing overall ongoing costs, this ensures efficient operation of the facility.

HR Wallingford, has recently completed projects for port terminal operators, where dredging optimization was vital to the overall project success. Optimization of the dredged areas’ extents and depths was performed using navigation simulations and sedimentation modelling, along with a tidal depth availability assessment and detailed analysis of historic sedimentation patterns. Support was provided through to completion of the works, with on-site support ensuring the contract, specification and schedule were met.

Mark Lee also said that in combination, these steps can ultimately lead to a significant reduction in the overall required dredge volume and improvements in dredging efficiency.

“Given that savings of the order of $4m have been realised to individual projects for individual maintenance dredges, whilst maintaining a safely navigable port, and that these savings are repeatable for future maintenance dredges, it’s understandable that dredging optimization is something that developers, operators and owners of maritime projects increasingly want to focus on,” concluded Mark Lee.