An Overall Applicable Strategy for Optimising Maintenance Dredging Works, a Case Study for the Port of Bayonne
Type:
Presented during:
WODCON XX: "The Art of Dredging" - 2013, Brussels, Belgium
Authors:
De Wit K, Fages S
Abstract: Almost all port authorities worldwide sooner or later ask themselves the question whether or not their port nautically is maintained in the best possible way, both result-oriented as economically. In an objective decision process several parameters should be evaluated. In general, a complete analysis includes the following steps:
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Identification of the quantitative dredging needs of the port
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Identification of the qualitative constraints of the dredging area(s)
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Based on 1 and 2, identification of the most suitable dredging equipment(s) and methods
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An estimate of the yearly cost for the port for the most attractive solutions. In this calculation 2 options are considered: subcontracting partly or completely to a third party or organising the works with own (existing or newly-purchased) equipment.
In this paper, a profound insight in the above mentioned steps is given. The whole process is illustrated by the presentation of a case study for the Port of Bayonne, a medium-sized port situated at the south of the French Atlantic Coast. In 2009, the French Region d'Aquitaine together with the Chamber of Commerce of Bayonne ordered a dredging optimization study to check the viability of the way their maintenance dredging was organized at that time and to investigate possible improvements on the long term.
After going through the first 3 steps, a highly flexible tool was created specifically for the port. It allowed the stakeholders to compare different dredging method options financially for varying economical input parameters like fuel price, personnel cost, depreciation options and interest rates but also operational parameters like working hours and exploitation levels. As a basis for the cost calculation, cost standards for dredging equipment, collected by CIRIA, were used for the main equipment. Where necessary, these basic data were completed with constructor's and suppliers' info for the more custom built equipment.
Keywords: maintenance dredging, optimisation, cost calculations, dredging equipment, dredging methods