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CONSTRUCTION WORLD
MARCH
2015
Themain approach walkway is slightly raised
above the site but handrails are omitted in
the main to facilitate movements of animal
species over and under the walkway.
“From the viewing platform, visitors
will walk on the suspended walkway while
being shown the excavation and education-
about fossils, the site and the structure. The
‘suspended-from-the-roof-solution’ makes
it possible to bring visitors much closer to
the excavation than with more orthodox
walkway solutions,” says Nel.
Although it is envisaged that the struc-
ture would remain in use for several decades,
total removal would be possible leaving only
a minimal footprint on the site.
Changing seasonal colours are consid-
ered and the bark-coloured structure will sit
comfortably in both lush green summer and
winter Highveld khaki.
The unexpected white interior enhances
natural light; aided by a small skylight.
“With stainless steel and chrome details,
this creates a ‘modern laboratory’, while
contrasting to – and visually illustrating – the
economic simplicity of the main structure,”
explains Nel.
The on-site construction period was
reduced by designing and manufacturing
the structure in separate parts that could be
erected for a trial period and testing off-site,
dismantled into the eight legs with a section
of the main truss attached, and then bolted
together again on site in the eight pieces.
“The rights of the environment are
becoming increasingly important on an ever
densifying and populated planet. Architects
have to stand up for the environment and
through actual buildings illustrate the possi-
bilities of minimal impact on pristine sites.
“This may be one of the most impor-
tant contributions this structure can make,”
he says.
Innovation
“The main body is very slender and was
constructed from an oval shaped lattice
girder, connected to the top of the eight legs
and supporting rafters that span out from a
central point of the roof. The top of the struc-
ture is 11 metres above the ground,” says
sructural engineer, Peter Fellows.
“The structure also has a steel viewing
deck capable of taking a maximum of 33
people. It is suspended from underneath the
lattice girder and the roof using steel ties. A
hoist is suspended from the viewing deck in
order to assist in the removal of fossils from
the site,” he continues.
“The legs supporting this structure are
connected using hinges allowing them to
swivel horizontally. This is important as the
exact location and level of rocks used to
found them could not be determined at the
design stage and were only determined once
on site. The upper legs branch outwards at
an angle and connect to a plate and then to
a lower leg standing at a more vertical angle,
creating a bend that resembles a ‘knee’”.
Engineering
The final shape, when viewed from above, is
like a beetle with eight legs.
It was decided that during construction,
once positions were chosen, rods would be
drilled into rocks around the site onto which
would be welded base plates. That of course
requires that the eight columns are adjust-
able to suit the positions once identified.
How was this achieved? The roof was to
be ‘rondavel-like’ in shape but not neces-
PROJECT PROFILE – STEEL CONSTRUCTION
26
The structure also has a steel viewing deck capable of
taking a maximum of 33 people. It is suspended from
underneath the lattice girder and the roof using steel ties.