p/Cover Story/Sep - Roof & Facade

Roof&Facade Asia
10 Roof & Facade Asia • September 2004
Translucent & Transparent Materials • Solar Control
Glass application at Hangar 7
of Salzburg Airport
THE new Hangar 7 at Salzburg Airport in Austria, is
located on the east side. Architect Volkmar Burgstaller
has designed the highly regarded steel and glass structure.
From floor to ceiling, uninterrupted spans of fireresistant
glass, made by SCHOTT JENAer GLAS of Germany,
for the first time in these dimensions, bring the
desired transparency and lightness via the glazed facades,
right into the interior of the building.
In geometrical terms, the futuristic steel structure
alongside the taxiway is an ellipsoid, turned slightly on
its longer axis and sunk into the ground, resulting in the
largest possible cross-sectional area. The impressive dome
rises up in an unsupported 66 m x 95 m span, to an overall
height of more than 14 m. On the northern side, the
ellipsoid is cut away on the diagonal, to open up a 350 sq
m gate, on to the taxiway and runway, providing a view
of the airport terminal building.
Two 5-storey cylindrical glass towers are built into the
hangar on its southeast side. Bridges and galleries link
them together and ensure that the main structure is solid.
The main entrance is located between them, giving access
to both the exhibition and the catering facilities. The
Skywalk leads, via the terrace, in front of the first-floor
restaurant, to the Skybar suspended below the dome,
which has glass floors and walls, to provide a view from
the highest point of the structure.
‘The maximum expanse of glass supported by the
smallest possible steel profiles’ was the specification presented
to Waagner Biro Stahl-Glas-Technik AG for the
design of the glazed roof. The diameter of the steel tubing,
which had to be bent to achieve the varying radius,
had to be kept to less than 406 mm. After numerous calculations,
the design, especially the way the ellipsoid and
glass towers combined, was optimised to meet the required
specification. The fact that there is an overhang
on one side of the hangar shell, resulting from the slight
turn on the ellipsoid, was an extra challenge in all of this,
as was the uppermost area of the shell, which presented
a leakage problem resulting from its low curvature. The
solution was a suspension in the dome area, in a geometrically
adapted form which now supports the Skybar.
In other areas, horizontal rings and infills were added to
the radial support structure, to stiffen it.
The secondary structure required to support the
glass, consists of flat steel members welded to a support
frame. The whole shell of the hangar is enclosed
in laminated safety glass. This is point-bolted and bent
in some parts. It is silk-screened on the outer surface
to provide solar protection. The largest panes, at
around 5 m x 2 m in size, are at the limit of what is
technically feasible.
The facades of the two cylindrical glass towers are in
the form of a double skin. The inner skin is insulating
glass with a solar control and heat protection function.
The individual panes go from floor to ceiling without any
other support on each floor. The gap between the inner
and outer skins is ventilated and incorporates concealed
solar protection in the form of external blinds. The external
shell itself also consists of floor-to-ceiling, point-supported
laminated glass panes which are supported without
frames via glass blades and which can be opened for
cleaning purposes.
The building control authority required fire protection
compartmentalisation at the structural interface between
the glass towers and the hangar. To comply with
the wishes of the architect and the building owners, this
also had to be in glass. A special difficulty in this connection
was the fact that the slight turn on the ellipsoid, resulted
in the facade overhanging in places in this area.
From an extreme inclination of 12°, it progresses continu-
PYRAN S borosilicate fire-resistant glass at Hangar 7 has opened up a new dimension of transparent architecture in a format previously unattained in frameless glazing.
ously to the perpendicular at the point where the glazed
double doors are fitted, providing access from the foyer
to the exhibition hall. Fitting a succession of diamondshaped
panes, over the 4 m length of the side edge, would
have created the risk of a 4 cm bow, with the consequent
danger of structural damage at a later date. In order to
butt the glass together without bow, in other words, to
deal with both the inclination and the horizontal succession
of polygons, the panes of glass were based on a
frustum and produced as distorted diamond shapes, the
actual glass being flat. As a consequence the joints are
not parallel, and the panes of glass appear to be tilted
outwards. The greater the inclination, the more obvious
this becomes.
The contract for this specially produced fireresistant
glass went to the Special Float Glass Division of
SCHOTT JENAer Glas GmbH. The company says that
PYRAN S borosilicate fire-resistant glass at Hangar 7
has opened up a new dimension of transparent
architecture in a format previously unattained in
frameless glazing. The fire-resistant glass separates the
two fire-protection compartments over a floor height of
up to 3.40 m. It is supported without the use of vertical
profiles from floor to ceiling, with the supports required
‘concealed’ in the floor covering and ceiling cladding. The
company supplied, among other things, 20 t of double
pane PYRAN S 10 mm thick laminate, 65 of which alone
measured 1200 mm x 3400 mm. Other pieces were made
to templates and had edge cutouts of up to 65% of the
glass area, or were made as stepped insulating glass.
Some adaptation of the production had to be carried out
both for the manufacture of the basic glass and also for
the toughening and laminating. RnF
Enquiry No: 09/110