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geotechnical project reliant on
compression modelling.
In layperson’s terms, the question
was this: how much material would be
required to compress and consolidate
the poor quality soil structure to
provide a sufficiently strong platform
to support the new runway system?
Hence the magic 11 million cubic
metres, supplemented by the driving
down of no fewer than 333,000 wick
drains, specially configured vertical
drains, to further draw away water to
assist the consolidation process.
Inclusive of the initial project
set-up and subsequent land clearing,
it has taken about five years to reach
the current project stage of a platform
strong enough to herald the start of
construction of the runway proper.
In the meantime, work is underway
on a key allied project, the delivery of
a vehicle underpass beneath taxiways
that will link the new runway system
to the existing system and terminals.
It will be built to carry an aircraft
design weight of 710 tonnes, or – as
parallel runway project director Paul
Coughlan puts it – “an A380 plus
20 per cent”.
As an indication of the depth of
research involved in planning the
taxiway weight-bearing capacity,
the project team examined the
development of major aircraft by type
over a 20 to 30-year period, from base
model to stretched versions. In almost
all cases the final stretched version of
an aircraft type added 20 per cent to
the MTOW of the original – hence a
projection based on the current largest
passenger type plus 20 per cent.Taking shape
Coughlan speaks about sand, fine
crushed rock, concrete and asphalt
with a depth of passion many of us
reserve for the sight of a vintage
aircraft in flight or the latest prototype
rolling off the production line in
Seattle or Toulouse.
With previous experience as a
private pilot, and a work background
as an engineer specialising in ports
and harbours, he was well placed
to not only understand the aviation
aspects of what he regards as a “once
in a generation” project but also
the circumstances that would bring
Moreton Bay into play as a key source
of the runway underlay.
Cue the arrival in 2014 of one of
the world’s largest and most modern
dredgers, the Charles Darwin, ownedBNE-feat
‘Once fully
operational
in 2020, the
runway will
effectively
double BNE’s
current
capacity.’