The go-ahead for the Scheldt deepening work was officially given on 12 February in a ceremony at the Antwerp North Sea terminal, by Flemish minister-president Kris Peeters, Flemish government minister Hilde Crevits (Transport & Public Works), the Dutch secretary of state Tineke Huizinga (Transport & Canals) and the alderman for the port of Antwerp Marc Van Peel. The current round of deepening is a continuation of the work that already started on the Flemish side in 2007. The deepening offers great advantages for the accessibility of the port of Antwerp. Apart from permitting wider tide windows, it is expected that container ships with greater draughts will be able to sail downriver after the deepening work, so that vessels will be able to leave the port with a draught of 15 m or more, depending on the ship.

The treaty entitled “Development Sketch 2010 for the Scheldt Estuary” signed on 21 December 2005 between the Netherlands and Flanders lays down that the navigation channel will be widened and deepened so as to increase the tide-independent navigation from the present draught of 11.90 m to 13.10 m. In nautical terms a keel clearance of 12.5% has to be allowed on the Scheldt on the Dutch side. This means that under the terms of the treaty the Scheldt will be deepened to a level of 14.70 m at average low spring tide. The keel clearance includes a margin for the squat effect (the fact that ships under way have a greater draught), plus a safety margin for ship movements under wave action, a margin for sudden silting up between two soundings and a dredging tolerance.

The deepening of the Scheldt also offers great advantages for tide-dependent navigation. In the first instance, the tide windows on the Scheldt will be considerably widened, thus further improving the safety of shipping. The wider tide windows will also permit ships with greater draughts to travel on the Scheldt.

At the moment, ships travelling up river to Antwerp have a depth of up to 15.56 m available to them. For sailing down river new regulations were drawn up by the Joint Nautical Authority, under which certain container carriers have up to 14.80 m available (tide-dependent), depending on their speed and sailing characteristics.

It is also expected that after the deepening work the maximum depth of container ships sailing down river can be increased, permitting a downstream draught of 15 m and more, depending on the speed and sailing characteristics of the ship. It goes without saying that the hydrological and meteorological conditions play an important role. As in the past, the necessary investigations into these aspects will be carried out by the Flemish government’s MDK agency. The new maximum permitted draughts after the deepening work will be determined gradually, on the basis of tests in the hydrological laboratory, test sailings and the experience gained.

Source: www.dredgingtoday.com