Port of Helsinki
13.5.2022 11:30:45 //
Juha Peltonen
Port of Helsinki

Tunnel routes to be assessed

Four route options for the port tunnel will undergo environmental impact assessments.

A key component of the Port of Helsinki’s development programme is a port tunnel that will connect the West Harbour to Länsiväylä highway. This tunnel will be used by all heavy traffic passing through the West Harbour. It will enable the consolidation of Tallinn-bound passenger-car ferry traffic on the West Harbour and the Swedish ships on Katajanokka, thereby freeing up a large area of the South Harbour for other use by the city.

In the previous design phase, the tunnel’s route was based on the space reservation plan. In January, the City began drawing up a component master plan for the entire Länsiväylä area, that is, extending all the way from Salmisaari to the Espoo border. This will include more detailed planning for the port tunnel in the Salmisaari area.

“Our basic goal is to find a good overall solution, that is, one that will allow the city to expand towards Salmisaari and enable the port to implement its development plan,” says Rikhard Manninen, Head of the City of Helsinki’s Urban Planning Division.

He says that one of the main ideas will be to reclaim land close to Lapinlahti Bridge, which would enable new residential blocks to be built on the filled area. According to Manninen, the power plant is a major issue in the city planning solutions. Its fate will affect the location of the tunnel entrance at the Salmisaari end. The two main alternatives are by Lapinlahti Bridge or behind Ilmarinen’s headquarters.

“The location of the tunnel entrance will have an impact on other land use,” says Manninen.

More detailed information

In order to explore the development potential of the Salmisaari area, alternative plans for the tunnel’s route and entrances were drawn up in early 2022 within the technical constraints. Pekka Hellström, Vice President of Technical Services at the Port of Helsinki, says that four main options have been selected for further analysis and all will undergo an environmental impact assessment (EIA).

“We’ll gather more detailed information about the scheduling, technical and financial impacts of the alternatives while the environmental impact assessments are being carried out,” says Hellström.

He says that the main differences between the alternatives stem from how they take planning reservations for the central tunnel into account, for instance. Although the central tunnel does not appear to be moving forward at this time, it still has a legal planning reservation that must be taken into account in the design of the port tunnel.

Port tunnel

The options have been named with the letters A–D. Route D differs most from the others, although the depth of the tunnel varies between all of the options.

“The geometry of the tunnel varies between all of the alternatives, as does the tunnel entrance and its location at the Salmisaari end,” says Hellström.

The formal public announcement of the EIA programme will most likely be made in August, as there would not otherwise be sufficient preparation time and summer is not the best time to announce plans for urban residents to comment on.

“In order to engage in effective dialogue, it would be a good idea to wait until the summer holiday season is over,” says Hellström.

Residents – and anyone else who may be affected by the project – will be able to give their opinions during the EIA process and again when the city plan is being finalised. The proposal will be circulated for comments at both the beginning and end of the EIA process, so that opinions can be given on both the EIA programme and the EIA report.

Housing or energy production?

It remains unclear whether housing alone will be built on Salmisaari. The City’s energy company, Helen, has some old oil tanks under Länsiväylä highway. Two of the three tanks have been decommissioned, while one is still in use. Helen is exploring a transition to decentralised energy production, and these underground tanks could potentially be used as heat accumulators.

“These are just some preliminary ideas – no decisions have yet been made,” says Ilkka Ruutu, Vice President, Real Estate at Helen.

He says that Helen will need to retain the entire area for energy production in the future.

“The western half of the city needs heating energy, and it makes sense to produce it in the west as well.” Several studies of potential production methods are currently being conducted.

Ruutu acknowledges that the interests of energy production and Salmisaari’s residents are partly at odds with each other.

“If the existing underground oil facility is removed, the tunnel project would have to build us a replacement. It cannot simply be decommissioned,” says Ruutu.

Demanding bedrock

The oil facilities within the rock also pose a technical challenge for the tunnel construction project.

“The lowest excavation depth that would leave the tanks undamaged is minus five metres, that is, five metres below sea level. Option C remains at that level, but option D would cut through the tanks and is the most difficult alternative from a technical perspective,” says Hellström.

The oil facilities cut into the rock are watertight structures, and their integrity could be compromised if the excavations come too close. That is, the excavations could cause cracks or holes in the rock that would allow water to leak into the oil tanks. Making a bridge through a tank would probably require filling the tank with blasted rock waste or concrete.

“Another option would be to go a little closer with a watertight concrete tunnel under the bedrock. The bedrock in the surrounding area is very demanding in nature. We’re working with Helen and the City to carry out studies for this project, the likes of which has never been done before in Finland,” says Hellström.

Once the studies being carried out by the port tunnel’s general planner, AFRY, have been completed, we will know whether any route options need to be discarded for technical reasons.

The port tunnel’s route will ultimately depend on what kind of tunnel would be most appropriate considering the technical constraints and what use the City wants to make of the land in the Salmisaari area. The location of the entrance at the port end of the tunnel has already been determined: it will be under a new terminal building whose working title is the Sea Travel Center.

The EIA procedure for increasing the capacity of the West Harbour (which includes the tunnel routes) also includes changes to berths in the West Harbour, that is, changes to land reclamation in the south and changes to quays along the eastern edge. The port’s EIA consultant is AFRY. According to the basic plan, the EIA process should be completed sometime in the second half of 2023.

Port tunnel
Reclaimed land is marked in red on the map.

“Land reclamation requires a water permit, and we will submit our application at the beginning of next year. It will be left pending until the EIA is ready, after which it will take about a year to process. It would therefore be mid-2024 before the water permit is issued and the port expansion can begin,” says Hellström.

The extension will cover an area of approximately two hectares.

City planning launched in Katajanokka

The city planning process has already begun in Katajanokka with the drawing up of planning principles. It will also include a decision on whether to expand the existing terminal or replace it with a new building. Hellström estimates that the planning phase will last until mid-2024.

The Port of Helsinki has not drawn up a new version of its development plan, even though construction costs have risen sharply in recent months.

“Our key tasks are now to choose between the four route options for the port tunnel and launch the EIA process. The final choice will primarily be influenced by the City’s planning projects outside the port and Helen’s projects in Salmisaari. No construction will begin until the second half of the 2020s. Although there is currently
a spike in energy costs and material prices, the key question for us will be how these costs evolve in the long term,” says Hellström.

A small part of the development plan has been put on ice: it was originally thought that when demolition of the old T1 terminal began in the West Harbour, temporary premises for St Petersburg traffic would be built in the South Harbour close to the Market Square.

“However, it’s quite clear that nothing will be done with regard to St Petersburg traffic this year, and there’s also a big question mark over its future. We will continue with T1 planning and our development programme, but will reassess St Petersburg traffic when the political situation becomes clearer,” says Hellström.