Korkeasaari Zoo, located in front of Helsinki, is one of the oldest zoos in the world and attracts about half a million visitors each year. The zoo has about 150 species of animals and its’ focus is not only environmental education, but above all the protection of species and the preservation of biodiversity. One form of conservation work is Korkeasaari Wildlife Hospital, which receives wild animals in need of aid. One of these animals needing help was also a Saimaa ringed seal which was found injured in Piitsniemi, Puumala and could not be returned to Lake Saimaa after it was recovered. In Korkeasaari, heads were put together and and an idea of a floating ringed seal basin was created for this unique individual.

Everything starts with good planning

Sanna Hellström, MD of Korkeasaari

“Pretty soon after we got Topias to us, we got the idea that the water area connected to the zoo could somehow be used to build a pool,” says Sanna Hellström, Managing Director of Korkeasaari Zoo. Allas Sea Pool, the floating sea bath located in front of Helsinki, is one of the Bluets’ most famous projects in Finland, and when Korkeasaari found out who has been behind the project, Bluet was soon contacted. As a result of the meetings and discussions, the common ground was quickly found and a suitable floating pool solution to become the new home for Saimaa ringed seal was going on the design table.

Bluet specializes in floating construction and especially floating pools – therefore this floating ringed seal pool fitted perfectly into Bluet work scope. The whole team took the project eagerly in hand and to give the best value to the client and especially the end-user Topias who melted everyones heart. Some specialist experts were also gathered along for this unique and special project; in addition to Korkeasaari team, there were also aquarium and aquatic experts, as well as technical equipment and pool experts.

Location in between Hylkysaari & Korkeasaari

Planning phase is definitely one of the most important steps in implementing floating solutions – or any other construction project. During the preliminary study, we carefully explored the water site between Hylkysaari and Korkeasaari where the pool was going to be located; depth, ice conditions, soil etc. We also studied thoroughly different options for how to transport pool modules and other materials to construction site and how to assemble all on site where no land is available for the construction works. During the design phase, the steel barge structure itself was also modelled following the site conditions and needed special technology requirements with detailed assembly plan.

Construction and assembly on water

Site design and well planned transportation are important parts of the project planning and pricing process. In the case of the floating seal basin, they played a particularly important role when it was found that the only option for transportation and assembly works was to do all completely over water. Before this conclusion various options were studied with crane and cargo companies and finally the best solution was to use heavy transport barge, which could then also be used for crane and lifting works on site. The traditional way for assembly works would be on land but due to the conditions at the site, this was not an option. The new way of working on water will get us to go to more challenging locations and save the nature on the land and waterfront.

Bluet’s Technical Director and Chief engineer Kimmo Saharinen, who has long experience in contracting and floating construction, emphasises the importance of design work phase. “The ringed seal basin was a special solution that required careful planning work and cooperation with various designers and specialists in its background,” says Saharinen. The design of the floating basin had to take into account all the special the needs of the ringed seal but also the visitors of the zoo, the construction site itself, special requirements of floating construction and also landscaping.

A team of designers and Korkeasaari experts became acquainted with existing different seal pool solutions by visiting various zoos and found out, what has worked and what has not. There are also ponds made for seals elsewhere, but this floating seal pool would be a unique solution – worldwide.

Planning from many perspectives

In addition to Bluet and Korkeasaari experts, the design team also had architects, special designers, pool and equipment experts.

Landscaping scale model by Koda Creative in the making

The most important thing in the design was to ensure that the end-solution would be as good as possible and a safe and functional habitat for the Saimaa ringed seal. Within the collaboration of the whole team – Korkeasaari Zoo, aquatic and aquarium experts, Bluet Team –  it was studied and taken into consideration what kind of a nest cave was needed, what feeding area would need to be like, how the water flow should be led so that the animal can clean itself, what are the suitable colours and materilas of the pool coatings, what kind of ramp the ringed seal could use – or could it injure itself somehow in the pool.

In landscaping, the attention was paid to the fact that the habitat would mimic Lake Saimaa – the natural habitat of Saimaa ringed seal – as much as possible with its rocks, islets and vegetation.

There were several technical issues specifying the chosen solutions: one major issue in the design works was to design the pool to be multi-purpose, ensuring that both, salt and fresh water can be used in the basin. The final basin size was based on the size of the selected location, its’ depth and especially the required living space for ringed seal specified by the authorities. The area was carefully inspected by divers, after which the pool was 3D-modelled to support the design works.

It was also important to plan and predict, among other things, how the separate pool sections will be cleaned, how electricity and other technical strokes will react during different operations and maintenance works – and how the pools remain stable when e.g. drained and emptied and therefore rise more than three metres upwards.

Visuals about pool tech design works

In addition to these, the people who are most important to Korkeasaari Zoo: the visitors, there experience at the seal pool was also needed to take into account in the planning.Issues such as how close to the animal can the viewers can be allowed to go, would and could the animal be dangerous to people and, on the other hand, how to ensure that the animal is not disturbed by the visitors. And not to forget the detail that also alternative uses for the basin was also considered during planning stage and the solution was designed to serve and be the home for other aquatic animals as well, e.g. otters or other seals, but it can also be used as a temporary location for an animal whose own pond or basin is being renovated.

Effective and professional cooperation

“From the engineering point of view, the whole project and its’ design works was very interesting as well as positively challenging – and was carried out smoothly in close cooperation with the entire project and Korkeasaari team. The design progress was presented to the client regularly and a joint zoo tour around Europe opened the eyes a lot! Perhaps the most surprising thing was how there was no single correct answerwhen considering and choosing the best technical solution. Zoos have been built during different decases and countries so each zoo and solution was pretty  much unique and not comparable as it is. Therfore the floating end-solution was not the only reason why the Saimaa ringed seal pool was also unique from the designer’s point of view,” Saharinen continues.

Korkeasaari was also very satisfied for Bluet’s service and design works. “It was known from the early stages that this is a unique solution. The cooperation with Bluet went great from the start. Everything that was done together went well and happened on time. We felt Bluet had creative ideas and they understood well what we needed. We know about animals and they know about the design, construction and special requirements of floating pools. Sometimes communication in this business field can be difficult and you’re expected to know and ask about issues and details for something you don’t even know about. With Bluet, this was not an issue.They could be told what the animal, the animal caretaker and the visitors and spectators needed, and from there came the technical solutions. Building a zoo is always special construction, which means that the design works are extremely important before the end-solution can be built. I could conclude that the cooperation with Bluet went extremely well, I can highly recommend!”, Hellström sums up.

Topias, picture

The project was completed up to approved  building permit and was moving forward when Saimaa ringed seal Topias, who was treated at Korkeasaari Wildlife Hospital, died unexpectedly. At the moment, the project is open, but once good plans exist, they can be used in the future to build either a ringed seal or other aquatic animal basin.