Allas Sea Pool Boasts Unique Engineering

The Allas Sea Pool marine spa, opened next to the Market Square in Helsinki in the autumn of 2016, has rekindled the Finnish capital’s historic status as a spa town and opened more of the city’s precious shoreline to the public. The technically unique complex is designed for year-round use and has attracted interest in the other Nordic countries.

Read more

Unique Engineering

The construction of the floating part of the spa was managed by Marinetek Finland Oy in partnership with Bluet Oy. Kimmo Saharinen, Technical Director at Bluet, has ample experience of challenging construction projects of various sizes. “As is often the case, many of the solutions were settled on as the work progressed. We made decisions in collaboration with Marinetek and our other partners,” Saharinen explains.

What was the biggest challenge of the venture? “The floating pools are filled with heated mains water on the one hand, and filtered seawater on the other. This is achieved through experimental technology involving pumping, filtering and carrying seawater, among other things. The floating structures are also subject to stress. Hence the modular high-density concrete and steel pontoon structure is supported by piles and anchored using wire cables. The double-hulled steel pontoon that bears both the fresh-water pool and the spa’s technical equipment was constructed using ship technology in Teijo (southwestern Finland), and floated into place. It was placed on the outside edge to protect the other structures,” Saharinen says.

A widely applicable concept

Allas Sea Pool will be open right through the Finnish winter, which poses a whole new set of engineering challenges. “The pipes are insulated and heated through trace heating. The kids’ pool and showers are emptied out, while the water in the cold-water pool is circulated similarly to ice-swimming sites in Finland. If necessary, we can fine-tune our solutions after the first winter.”

Saharinen claims that the successful Allas Sea Pool concept can easily be adapted by other countries and seaside towns. “The initial analysis is crucial. The chosen construction methods and engineering solutions depend on the water-borne traffic in the area, the tides, the make-up of the sea bed and the anchoring opportunities. This will also determine the extent of the required investments.”

Valuable experience for Bluet

Saharinen is satisfied with the project’s end result. “This was a valuable experience for us, and it brought us even closer to Marinetek as partners. The complex is a tour de force of modern technology, and its opening was eagerly awaited by the whole city. The doors were opened first to the crowdfunding investors, and on the very same evening to the greater public. Everything has gone superbly and the pool’s popularity has exceeded all expectations. We are still making minor adjustments based on feedback from our visitors, but then we will be done.”

Technical Director Kimmo Saharinen (Bluet Oy Ltd)

Up-and-Coming Western Helsinki Hones its Seaside Image

Project Director Outi Säntti (City of Helsinki)

The City of Helsinki has long held the principle that most of its shoreline should be open to everyone. In coming years more unrestricted coastal routes, residential buildings and recreational services will be opened in the city’s seaside districts. This will enhance the diversity and attractiveness of Helsinki to both residents and visitors.

Project Director Outi Säntti is in charge of coordinating the development of the West Harbour district on behalf of the City of Helsinki. The city wants to create a high-quality coastal area where people will love to spend time, both at work and off-duty. “People are looking for new ways to spend time. Seaside Helsinki has potential for offering completely novel experiences,” Säntti says.

After the success of the Allas Sea Pool in the city centre, there has been talk of a similar floating marine spa being installed in Western Helsinki. One possible location is Hyväntoivonpuisto park in Jätkäsaari, whose initial plans already included a swimming spot. “The floating solution is interesting for the city council for various reasons: it does not require a conventional beach, it permits year-round swimming, and it is a modern kind of privately operated leisure activity that is attractive to the public. A suitable partner could be found in a chain of hotels or spas.”

Säntti believes that Helsinki’s maritime character is a clear advantage for the city. Being in possession of as many as 130 kilometres of coastline offers compelling development opportunities for the increasingly cosmopolitan capital.

”I love it here!”

Taimi is a seven-year-old girl who loves splashing about in the water. Her father took her to try out the Allas Sea Pool on the very weekend it opened. She was thrilled with the excitement of the place and the opportunity to swim outdoors.

Tuomas Pakka takes his daughter swimming a lot and is very happy with the new swimming experience offered by the Allas Sea Pool. “It is completely different to swim while admiring the hustle and bustle of the market square, the maritime traffic and the splendid surrounding architecture. The first time we came the weather was rather nice, but even though it has been less favourable since, we’ve enjoyed the pool just as much. Taimi loves it here,” he laughs.

The bit Tuomas and Taimi like best is the large freshwater pool that is kept at 27 degrees Centigrade. “Taimi knows how to swim and dive, and that’s more fun in a big pool. It also feels warmer to be surrounded by more water, which I particularly appreciate. Taimi wants to stay in the water as long as possible and this pool is warm enough for me, too.”

Both father and daughter find the combination of sauna and outdoor pool enjoyable and refreshing. They often top off their visit with a bite at the Allas Sea Pool café. While there, they usually start planning their next visit.

Taimi and Tuomas Pakka enjoying the sea spa.

Allas Sea Pool

• Floating deck surface exceeding 2,600 m2, with capacity for 3,500 visitors
• Three swimming pools: 25 m x 15 m heated fresh-water pool, 17 m x 11 m heated children’s pool and 25 m x 12 m seawater pool
• All pools are embedded in a single floating deck
• Floating, pile-anchored, modular high-density concrete and steel pontoon structure
• 33 m × 22 m double-hulled steel pontoon contains the larger fresh-water pool and all the swimming pool technology

You find more information targeted to consumers from Allas Sea Pool homepages. From there, you will also find the companies and services operating in the marine spa.

Allas Sea Pool Homepages

Pin It on Pinterest