Excavation

The base of the sculpture is formed as the inner side of a spherical cap, the sphere having a diameter of 110.8 metres. Thus, on the basis of a level building site, about 7,000m3 of earth had to be excavated. About 14,000 m3 of filling had to be added.

Drainage Installation

A damp course has been formed under the asphalt base by laying down a 15cm layer of shingles. The drain pipe system is constructed as a percolation drain, which is led to the municipal rainwater system.
The construction of the drain pipe system has been based on the soil and ground water situation at the site.
Drainage from the exterior of the dome is through a rock filling along the circumference of the sculpture with the rainwater being drained off to the public rainwater system.

Concrete construction

The steel dome is supported partly by four steel pillars and partly by the circular continuous footing.
The foundations for the pillars and the continuous footing are cast on site in excavations to frost-free depth.
The width of the continuous footing varies from 0.8 to 1.0 metres, depending upon the bearing capacity of the soil.
The foundations for the pillars and continuous footing were cast in situ in shuttering.

Steel Construction

The curved surface of the sculpture is fabricated from 5-6mm sheet steel which is stiffened with rolled IPE 360 profiles (radial) and HE 140 A profiles (circular). The staircase is also constructed of 5-6 mm sheet steel.
All fabrication of sheets and profiles, and of the components of the sculpture (stringers and steel pillars) was carried out in engineering workshops. All components were fabricated in the maximum size suitable for transportation. The assembly of these components to form the completed sculpture was undertaken on site with the assistance of mobile cranes.
All seams between the steel sheets are welded and the joints between the sheets sealed with weld beads prior to surface treatment.
The steel construction is secured to the continuous footing by fittings cast in the concrete.
Likewise, there is a solid connection to the four steel pillars. Other than these connections, the steel construction is self-bearing.
The total amount of steel used is about 400 tonnes.

Steel pillars

The pillars were prefabricated in a factory. Each pillar has a diameter of 2m at the base and 1.6m at the top.
The steel pillars are topped with red glass domes with internal illumination.

Lightning Conductors

Each of the four pillars has a lightning conductor. The lightning conductors are connected to a common earth which is integrated into the foundations of the pillars and the continuous footing.

Gas Installation

A hollow pillar is situated in the middle of the dome. This pillar contains the machine room for the gas installation. A gas burner is located on top of the pillar, approximately 2 m under the top of the steel dome.