The deepening of the Vuosaari fairway and harbour basin was completed ahead of schedule at the end of November. During the project, around 1.1 million cubic metres of soil was dredged and 800,000 cubic metres of rock was made available for use in area construction in Helsinki.
The project was completed on schedule and under budget. The project, which started in spring 2020, cost 26.5 million euros. The original budget estimate was over 10 million euros more. The project has also been awarded a 20% EU CEF grant to improve transport efficiency and reduce environmental hazards. The project was under budget thanks to a favourable market situation, good advance planning and the competence of the contractor.
“The biggest single factor contributing to staying under budget was that the Vuosaari contract was tendered at the same time as the City of Helsinki’s Hernesaari dredging and filling contract, which made it possible to get a good bid for both. The chosen contractor, Terramare Oy, also has high-quality equipment and experienced personnel, which make for efficient work,” says Seppo Paukkeri, Project Manager at the Finnish Transport Infrastructure Agency.
“In addition to the concurrence of the two projects, the contractor’s previous experience in the construction of the Vuosaari fairway contributed to staying under budget,” says Jukka Kallio, VP Cargo at the Port of Helsinki.
For Terramare, the project was a typical dredging project in terms of difficulty. According to Vyyryläinen, the special characteristics of the project included the busy vessel traffic and the water intake of the power plant in the work area.
“The project was successfully completed with good advance planning, the project’s own innovations and the help of motivated and skilled personnel,” says Jani Vyyryläinen from the contractor, Terramare.
The construction consultant and supervisor for the project was Ramboll CM Oy. Ramboll also acted as project planner, geotechnical expert, safety coordinator, risk management expert and environmental expert and was responsible for the project’s communications during construction.
The project to deepen the Vuosaari harbour basin and fairway was completed on schedule, with 70 per cent of the budget spent.
Deepening work carried out safely amidst busy ship traffic
Safety was the top priority of the project, and the project team is pleased that the work was carried out safely all the way to the end. The project was carried out on a busy water area and required significant efforts to coordinate the vessel traffic, pleasure boating and work machinery. Vuosaari Harbour was kept open throughout the deepening project.
“The Vuosaari fairway has the busiest vessel traffic in Finland. The dredging and excavation work had to be carried out in the fairway in such a way that large cargo ships could safely pass. Every week, we had a joint traffic meeting in which we went through the upcoming work with the pilots of the VTS vessel traffic service, the shipping companies and the contractor and agreed on the rules to ensure safety. Although the work required additional signage and speed restrictions, all parties involved in the project were willing to be flexible and contribute to the safe implementation of the project,” says Paukkeri appreciatively.
“Throughout the project, reconciling the work and the safety of vessel traffic was a major challenge that was constantly invested in by the different parties involved. However, close cooperation between the project’s traffic coordinator and other parties involved created good practices for the safe implementation of the project,” says Vyyryläinen.
Larger ships will have access to Vuosaari in the future
Vuosaari Harbour is Finland’s busiest container harbour. The fairway is used by approximately three thousand vessels per year. Thanks to the deepening, Vuosaari Harbour will be able to receive larger container ships in the future. This will reduce the environmental impact of container transport, as larger loads can be transported at a time. At the same time, the use of larger ships will reduce transport costs.
“Vuosaari is Finland’s most important main port for international trade. The project is important for the Port, but even more important for the Port’s customers and, by extension, for Finland’s international trade,” says Jukka Kallio of the Port of Helsinki.
The new fairway was officially opened on 30 November 2021.
Building new Helsinki with excavated rock
Most of the rock excavated during the project, 800,000 cubic metres, was transported by water 21 km away to Hernesaari, where it was used for sea filling in the area. The amount of rock transported could fill the Finnish Parliament House approximately seven times. Transporting the materials exceptionally by sea reduced the environmental impact, traffic congestion and costs of transport.
“The transport by sea significantly reduced lorry traffic on the streets of Helsinki. The solution replaced about 40,000 lorry loads and reduced fuel consumption by 1.1 million litres and carbon emissions by about 2,500 tonnes,” says Mikko Suominen, Land Mass Coordinator of the City of Helsinki.
In the 2020s, Hernesaari will be transformed through construction into a maritime residential area focused on tourism and leisure services, with port and industrial functions moving elsewhere.
Project followed by additional work to widen the buoy gate
In front of Vuosaari Harbour, there is still a point that is narrow for ships, the so-called buoy gate. The project will now be followed by the widening of the buoy gate. The work has been granted a water permit by the Regional State Administrative Agency. The widening of the buoy gate is well suited to be carried out in the wake of a larger project, reducing the overall negative impact. Autumn is a good time to carry out the widening work from the cabin owners’ point of view as well. The work started in October and will be completed at the turn of November and December (the project will end for contractor Terramare).
In addition to the widening of the buoy gate, further work will be carried out in 2022 on the deepening of the Kuiva Hevonen marina and the construction of a breakwater. Both of these additional works are part of the EU funding.
New ways of working reduced environmental impact
The rock masses excavated during the work were utilised in area construction in Helsinki, and their transport to the construction site by sea reduced the environmental impact, traffic congestion and costs caused by the transport.
The environmental impact of the work was monitored regularly. The impact of the project on the fish stock will continue to be compensated for by stocking 40,000 young whitefish in the area every year until 2023. This year’s whitefish stocking took place at the end of September.
The impact of the project on the waters was closely monitored throughout the project through turbidity measurements and surveys, aerial and satellite images and water sampling. Based on these, the impacts have been found to be as predicted. The turbidity was limited to the area around the work machinery, and particularly during the spring runoff period, it was difficult to distinguish the turbidity from the load of solid matter carried by the rivers and the resulting general turbidity.
The environmental monitoring of the project included investigating the presence of various harmful substances in the marine area. The harmful tributyltin used in the anti-fouling paint of boats was the subject of a heated debate during the construction of Vuosaari Harbour in the early 2000s. However, the tin compound in question was no longer present during the current deepening work. The dredging extended to the deeper level of the now existing fairway.
During the project, underwater noise from the dredging and excavation work was also investigated. The report provided important information on the construction impacts of waterway projects for the protection of the Baltic Sea. You can read the article and report on underwater noise here. The report on the 2021 monitoring results will be published on the project website after the report is completed in the summer of 2022.