Dredging projects reach unprecedented number
An ‘unprecedented’ number of huge dredging projects has been planned for Sweden, with three particularly outstanding in terms of size.
The rise in number has resulted from the government’s decision to make large investments in rail, road and fairway, says the Swedish Maritime Administration (SMA), which says there have never been so many dredging projects in the pipeline as now.
The majority of the projects will involve the use of both environmental dredging buckets and trailing suction hopper dredgers, the SMA says.
1. Malmporten, Port of Luleå
The largest dredging project is at Luleå Port, in the north of Sweden, one of the country’s largest ports, which serves an Iron Ore Line to Narvik. In Swedish, ‘malm’ means ore.
The dredging will remove a massive 22 million cubic metres for a maximum draught of 15 metres – the maximum in the Baltic Sea.
It is estimated that the material to be removed comprises 1 million m3 of rock, 20 million m3 of sand and moraine (rocks and sediment deposited by a glacier) and about half a million cubic metres of ‘contaminated material’.
The work, which should begin in 2024 and take until 2026 to complete (only seven months of the year are possible because of ice in the other five months) will allow Luleå to accept vessels carrying up to 160,000 – more than three times the current 50,000-tonne weight maximum.
“Ability for larger vessels is crucial for Luleå,” says SMA. “Iron ore is a low-value commodity, which demands ships with high cargo capacity to keep transport costs as well as fuel consumption and emissions low. Higher cargo capacity is also important for inbound shipments of coal to the steel work.”
The port has bought the Robert Allan tugboat Vilja, which has hybrid propulsion and 1m ice-breaking capability at 3 knots, to assist the larger vessels that will be accommodated at the port after the project.
Tenders will be invited in October.
2. Skandia Gateway, Port of Gothenburg
Plans to begin dredging about 13.5 million cubic metres of clay and rock to a depth of 20.5 metres have been pencilled in to begin in August 2025, but could be brought forward a year if possible, the SMA says.
The work will widen and deepen the northern fairway to the Skandia Harbour and turning area at Gothenburg, which caters for the world’s largest container vessels and provides direct routes to the Far East from Sweden.
Similar dredging work was carried out there between 2002-2004, so the SMA says the area and any risks are well known.
The SMA will look after the fairway, while the Port of Gothenburg will be responsible for dock measures, including dredging 50 metres from the docks.
Permits will be sought for about 285,000m3 of contaminated material to be dumped at sea and then covered with 10m3 of clean dredged clay.
Depending on the decided start date, tenders will be invited in 2023 or 2024.
3. Landsort Fairway
The third project will actually create fairways between between Fifång–Regarn and Oaxen–Skanssundet for the first time in modern history, the SMA says.
One million m3 of about 950,000m3 of loose clay and cohesive matter and 70,000m3 of rock will be dredged and new fairway parts established, alongside other minor trimming projects, the SMA says.
“Permit to sea disposal of the spoil will be applied for. The dredgable material is divided into two types, clean masses and a minor amount of contaminated dredging spoil,” says the brief. “The clean dredging masses are planned to be disposed of in the proposed disposal areas without specific restrictions. This consists of sand, gravel, blasted rock and clay without contaminants, but also mud and similar material with some degree of contamination.
“The moderately contaminated soil requires specific management. The plan is to dredge this material, approximately 20,000m3 in situ, early on in the implementation phase and dispose of this at the bottom of a suitable disposal site. The moderately contaminated spoil is planned to be dredged by using an environmental dredging bucket.”
The Landsort fairway is a busy area, with about 2,500 vessel movements taking place each year. This traffic will continue during the dredging works, which are scheduled xto begin in August 2024.
