Principal and architectural design

South-Hermanni Underground Parking Facility

The South-Hermanni parking facility serves residential and commercial properties in the area. There are 336 parking spaces, as well as five stairwells and four elevators to the surface level. The design of the parking facility has considered the landscaping and fit of the above-ground entrances as part of the surrounding urban structure.

Paloheinä Public Transportation Tunnel

The Paloheinä tunnel is a traffic tunnel running underneath Helsinki Central Park for more than a kilometer. Rather than a new bus line passing through the, it was decided to run it through a tunnel under the park and preserve the recreational uses on the surface. Currently, the tunnel is only used by public bus transportion, but the design has also accounted for possible future tram traffic. The main 560 bus line using the tunnel carries passengers between Vuosaari and Myyrmäki.

Completed in 2015, the Paloheinä tunnel fell short of the budget by more than 6 million euros. The savings arose when the plans were simplified, and a single-pipe tunnel was built instead of a two-pipe tunnel. The rock excavated during the construction of the tunnel was used in the area for the rehabilitation of the Paloheinä recreation and for the construction of the Kuninkaantammi area.

Kluuvi Parking Facility and Civil Defense Shelter

The Kluuvi parking facility was excavated in the bedrock under an existing service tunnel and about 26 meters under the existing Porthania building. When completed in 2000, the Kluuvi parking facility was the second largest underground parking facility in Helsinki. The facility has 725 parking spaces in two halls and three floor levels.

There is pedestrian access from the parking facility to the Kluuvi shopping center and the University of Helsinki metro station, connecting parking and civil protection with the surrounding Helsinki area. If necessary, the space serves as a civil defense shelter for 7,500 people.

Maunula Sports Hall

Responsibilities: Principal design and architectural design

The Maunula Sports Hall, completed in 1998, is located in an underground civil defense shelter. A ramp to the premises is accessible from Männikkö Road, but the public entrance is located on the Maunulanmäki side. The shelter’s primary function is an underground civil defense shelter. The principal building material used for the entrance building is reinforced concrete.

Moisture problems have been observed at the site, particularly in the floors, though leaks have been observed in the wall and roof shotcrete surfaces. The purpose of the project is to determine the effects of moisture problems in the lower floor of the existing sports hall, to redesign the floor structures in selected areas and to improve ventilation of the space.

Salmisaari Coal Storage

The four underground coal silos built in connection with the Salmisaari Power Plant in the early 2000s are located at a depth of 120 meters below sea level. When completed, the Salmisaari underground coal storage facility was the first of its kind in the world. The silos are 65 meters high, 40 meters wide and can accommodate 250,000 tons of coal.

The shape of the storage silos was a result of a shift to full automation. The cylindrical coal silo allowed for the use of gravity in the handling of the coal and it was also optimal for rock mechanical reasons. As a result of situating Salmisaari’s coal stores underground in the rock, the former surface coal field was released for commercial and office use.

Helen Oy is committed to phasing out the use of coal. Coal from the Salmisaari Power Plant is planned to be replaced by 2029. We look forward to seeing how Salmisaari’s underground facilities will be used in the future!

Sipoo Multipurpose Hall and Civil Defense Shelter

The 1,200-square-meter multipurpose hall and civil defense shelter in Sipoo was designed to be as spacious as possible, versatile and pleasant to use. The multipurpose hall was excavated in the center of Nikkilä to a depth of about 28 meters. If necessary, the multipurpose hall will be converted into a shelter for 1,800 people.

In normal use, the sports hall can be divided into four sections, one of which can be isolated with a sound-insulated partition curtain. During the day, the facilities are mainly used by schools, but the size of the hall is also sufficient for official floorball and handball matches. The viewing area has space for 250 people.

The multipurpose hall also has meeting rooms, a café and a gym.