The tower crane's tower, reaching up the side of the 40 storey building
on what is known as the Southern Cross site in Melbourne - a glass fronted
building on the corner of Bourke and Exhibition Streets in the CBD - was
alarmingly close to the glass … just 15 cm. in parts. It allowed
very little room for error, when 'climbing down' the tower.
The tower had originally been 'climbed up' by the company which had
been doing the crane work … but the head contractor, Multiplex, chose
BOOM Logistics for the very tricky task of 'climbing down' the tower,
after all the glass had been installed.
"It was agreed that it was a very tricky job … largely due
to the closeness of the tower to the glass. We had to tackle this job
in a very carefully planned way," said Drew Baker, General Manager
Tower Crane Division, for BOOM Logistics at the time.
"There were issues such as the possibility of tower flex, of up
to 30 cm. when tension was released, as a result of the tower stays being
disconnected, let alone the effects of any unexpected wind gusts.
"It was an exercise based on absolute precision, skill and experience
… and in the end it is experience that gets difficult jobs done quickly
and well," added Drew.
The other point of difference which experts were able to bring to the
'climbing down' of the tower for Multiplex, was a considerable cost saving.
"Whereas the conventional approach would have been to position
our mobile crane in the busy CBD street (Bourke St.) with the attendant
traffic management issues and interruption to tram services, we were able
to position our mobile crane quite differently.
"We were able to locate it in an unusual location by adapting to
a suspended concrete floor slab on the building site itself. This saved
the need for traffic management activity and creating hold ups for vehicular
traffic and trams.
"We estimate this ability to adapt, draw on our experience and
engineer the job in a better way, saved our customer in the region of
$150,000 … and in addition to that $150,000 saving there would have
been the cost of tram service interruption," added Drew.
|
Climbing down a tower crane can
be a task for specialists, especially when
the tower can be as close a 15 cm. to
the glass - Multiplex contracted BOOM
Logistics to carry out the job.
|
