international
construction
november 2014
LARGESTRUCTURES
40
Scaling new heights
Hong Kong heights
Three Liebherrs build observationwheel
T
hree Liebherrmobile cranes, includingHongKong’s first 400 tonne Liebherr LTM
1400-7.1 owned by rental company SetWinHeavy Lift, are performing key lifting
duties to raise a 60m high observationwheel on the central waterfront.
As part of thework, the new cranewas initially used to raise and hold in position the two
pre-assembled twin 36m longmain supporting legs and the central hub of thewheel, with a
combinedweight ofmore than 65 tonnes, positioned and held at an angle of 45°.
Additional Liebherr 100 tonne and 200 tonnemobile craneswere then used for the project
in tandem lifts to position the two remaining support legs, eachweighing 27 tonnes and
connecting to the central hub.
directly beneath the RiverThames to link-up with the existing
undergroundnetwork, theUK£200million (US$320million)
NorthWoolwich tunnel has encountered a number of technical
challenges during its construction.
With some 300 construction staff on-
site at any one time, the joint venture
between Hochtief and Murphy spans
2.5 km in length.
This required the efforts of two 7.1 m
diameter Herrenknecht tunnel boring
machines (TBMs) operated by crews of
20 workers on shift-patterns 24-7 for
nearly 18months fromMay 2012.
ProjectmanagerNeilMurray explained
that delivering it safely on time and on
budget were the key elements to the
scheme, describing completion of the
tunnellingwork as a “keymilestone.”
He said, “We aredelightedwith theway
the two tunnel portals have been formed
at North Woolwich and Plumstead.
We’re also extremely pleased with the
tunnelling – they are finished to a very
high quality and it has been done safely.”
The issue of following strict health and
safety guidelines has been of particular importance. Everything
frommaintaining an exact log detailing howmany people are
working below and above ground at any one time, to ensuring
construction workers are equipped with advanced breathing
apparatus in the event of a gas leak.
In terms of the tunnelling itself, the TBMs– known as
Sophia andMary (named after 19
th
century engineer Isambard
Kingdom Brunel’s wife and mother), have been built to cope
with the testing geological conditions below theRiverThames.
Clearly, using such immense machines requires considerable
expertise.What were the biggest challenges?
The project manager added, “The ground strata varied
dependingon thedepth and location - combinationof sand and
gravels and as we got deeper, we entered chalk – when you go
from one sub-strata to the next, that’s where the trickiest part
of the operation is, but we tackled this head on and we were
successful getting through each layer to the finish.”
HongKong
One region that has seen a particularly steep level of growth for
major construction projects has beenHongKong.
As Noel Kennedy, country director of RMD Kwikform,
enthused, the expansion of the construction sector had
prompted the company to review its strategies and approaches
to itsmajor projects.
These include the Kowloon rail terminus and the UK£ 6.5
billion (US$ 10.47 billion) Hong Kong - Zhuhai - Macau
Bridge, whichwas first mooted in the early 1980s and is finally
coming to fruition.
It will include a 12 km link road, boundary crossing facilities
for government officials and their respective departments, in
addition to further infrastructure development.
At 29 km in length, the bridge is one of the largest schemes
>
The Crossrail scheme in London is presently Europe’s largest
construction site. It includes a UK£ 200million(US$ 322
million) tunnel under the Thames at NorthWoolwich.
The Hong Kong – Zhuhai –Macau Bridge.
