The Utrecht train station square faced a complete make-over. Buitink Technology demonstrated a phenomenal piece of design and engineering work by installing innovative inflatable cushions in the dome at 30 meter height. A total of 49 transparent ETFE foil cushions were placed in the steel framework.

Design

Magnificent drawings visualized the make-over of the Utrecht train station square in the initial phase of the project. Our ETFE foil roof elements, placed in the round gaps in the roof framework, in reality showing the envisaged results as confirmed by below photo's.

Round inflatable cushions of ETFE foil

Buitink Technology provided 49 inflatable roof elements of ETFE foil, each with a diameter of 7.2 m. Inflating the foils, using controlled air pressure, creates a rain and storm resistant connection between cushion and frame work. The correct shape of the inflated cushion is created through cutting "banana shaped" strips of foil, which are welded together.

Project engineering ETFE inflatable air cushions

aBesides producing the round inflatable cushions of ETFE foil, Buitink Technology also did the engineering. Furthermore Buitink Technology delivered and installed the air compressor system with piping as well as the control systems. This system keeps the air pressure in the cushions at the correct value.

Strength calculations

In each project (so also in the "Utrecht train station square" ETFE air cushion project) a full scale strength analysis is done to calculate the forces exerted in and on the foil. An example of an analysis with various loads is given below:

Construction

Our construction team placed the ETFE cushions at a height of 30 m above ground level, including air compressor system, piping and control system.

Project data ETFE domes

Size:	49 ETFE cushions 7 meter diameter each
Material:	transparent ETFE foil, transparent
Client:	community of Utrecht
Architect:	Ector Hoogstad Architecten
Main contractor:	BAM
Construction:	Royal Haskoning DHV
ETFE domes:	Buitink Technology
Year of implementation:	2018