‘T IJ (name explanation: This is a Dutch word joke. ‘TIJ’ means ‘tide’ which refers to the returning tides in the Haringvliet, but quickly pronounced it also means ‘the egg’)
‘T IJ is the biggest and most striking of a series of objects designed to celebrate the opening of the Haringvliet sluices in November 2018. The sluices were opened in order to improve water quality and biodiversity, while also stimulating fish migration from the North Sea to the river delta system of Maas and Rhine in the Netherlands. This will create a new, salt-resistant and salt-loving natural environment. The biodiversity in the surrounding nature reserves will increase and a more robust, healthier ecosystem will develop in the coming years. To let people experience and explore these changes, a series of bird observatories have been designed in the Haringvliet area.
‘T IJ is an egg-shaped bird hide situated in Scheelhoek, a nature reserve close to the Haringvliet sluice near Stellendam, the Netherlands. The reserve consists of large reed beds on the inside of the coastal defences and some flat sand islands outside. These islands are breeding and feeding grounds for several species of birds like the common tern, spoonbill, and the icon of this area, the sandwich tern.
▼一个蛋形的鸟类观测屋，an egg-shaped bird hide
▼沙岛为一些鸟类提供了繁殖和觅食的栖息地，the sand islands are breeding and feeding grounds for several species of birds
▼白琵鹭（左）和白嘴端凤头燕鸥（右），Lepelaar Eurasian Spoonbill (left) and SandwichTern (right)
‘T IJ observatory is part of a large scale landscaping plan where people can experience the Scheelhoek nature reserve in a walk from the car parking area to the Ei. Walking along the path, visitors can view several types of bird biotope favoured by sand martins, several kind of waders and, of course, terns.
▼水岸视角，view from the waterfront
▼游览路径视角，view from the path
To prevent the birds from being disturbed, the last section of the path is actually a tunnel made of re-used mooring posts and second-hand azobe planks which were once used in the brick industry. The tunnel is covered in sand to provide habitat for terns or waders. The outside of the tunnel provides artificial nesting holes for sand martins. The end point of the walking route is the egg-shaped bird hide from where you can view hatching Terns and all the other species that live in and around the water.
▼隧道的外表面为崖沙燕提供了筑巢的凹洞，the outside of the tunnel provides artificial nesting holes for sand martins
The egg itself is modelled on a sandwich tern egg, and sits on a nest of sand, much like a tern would have done it herself. The nest of the egg consists of vertical ‘feathers’ of chestnut poles, reeds and small sand dunes. The egg itself is parametrically designed to achieve a good ratio between form, structural integrity, size of the timber, and size of the openings. The structure has been constructed as a File-to-Factory Zollinger to provide relatively big spans with small timber parts.
▼通过参数化设计建造的“鸟蛋”，a parametrically designed “egg”
▼“鸟蛋”表面细部，exterior detailed view
▼上下部分材料示意，materials: pine and accoya
The lower part of the egg, which floods a few times a year, is made of accoya. The upper part, which stays dry all year, is made of pine. The upper part is thatched with local reed, harvested from the inside of the sea defences. The thatched roof stops just above the highest possible water line. The floor inside the egg is a hybrid wood (CLT)- concrete floor which acts as a structural stabiliser and from where there is a beautiful view of the surrounding islands, the Haringvliet sluices and the water.
▼上半部分由松木制成，在全年保持干燥状态，the upper part, which stays dry all year, is made of pine
▼下半部分由固雅木制成，能够抵御每年数次的淹水，the lower part of the egg, which floods a few times a year, is made of accoya
▼观鸟步道，pathway for observation
▼“鸟蛋”顶部以茅草覆盖，the upper part is thatched with local reed
‘T IJ is thatched with local reed and has a timber structure which has been completely File-to-Factory produced in 402 parts and has been assembled at the site. It can be completely dissembled. Through its re-usability, its modularity, its materials and its contribution to the nature environment, it is almost completely circular and sustainable.
Reflecting the transitory nature of all things, it must also be noted that the Bird-EI is also temporary and will be taken apart at some point in the future. At that time, it may be reused or recycled without detrimental effects to nature or man. In this way, we have created an (eco)system where man and nature can come closer together and be a part of each other’s world.
▼夕阳下的观鸟屋，the bird hide in the sunset
▼一个新的生态系统，a new eco-system
▼3D形态和结构模型，3D shape and structure
▼结构单元示意，principle coding elements
Architect: RO&AD Architecten, Bergen op Zoom – RAU Architecten, Amsterdam
Design team RO&AD: Ad Kil, Ro Koster, Martin van Overveld, Athina Andreadou, Loyse Rebord, Rodrigo Altamirano
Design team RAU: Thomas Rau, Michel Tombal, Jochem Alferink
Commissioner: Vogelbescherming & Natuurmonumenten
main structural engineer : BreedID, Den Haag
Structural engineer wood: Aalto University Finland
Wood engineering: Geometria, Finland
Landscape: H+N+S Landschaps Architectuur, Amersfoort
Contractor: Van Hese Infra, Middelburg
Thatched roof: Elg Rietdekkers, Schoonebeek
photography: Katja Effting
location: natuurgebied De Scheelhoek, Stellendam, Nederland
Start-End construction: 10-2018 – 03-2019
Function: Vogelobservatorium / Bird hide, bird observatory