Dancing Towers on Hamburg's Reeperbahn - Putzmeister

Title story
p For some in St. Pauli, this early hour means hometime, but for the workers on the construction site, the day is only just starting:
At half past 5 sharp, the first truck mixers arrive.
Placing concrete - from a practical
viewpoint
Laughing when asked what the greatest
challenge for placing concrete is, project
lead Silke Pförtner from Ed. Züblin AG answers:
“When you see the depth of the pit, the
type of pit lining and the size of the area set
aside for the construction site equipment,
it soon becomes clear: There isn‘t actually
any space for large machines. In addition,
the hours allowed for concreting are clearly
delimited because we have to respect our
neighbours, and therefore we need as many
pumps as possible. So we have teamed up
with betonlift to develop a very target-oriented,
fair, good and safe solution. Because
when placing large amounts of concrete as
you see today, we really can‘t leave anything
to chance. So, for example, we worked with
betonlift to determine first of all the locations
of the three pumps (see fig. 7 and 9),
restricted as we were by a very small set-up
area, the maximum load on the supporting
ground at the edge of the pit, and the access
options for the truck mixers.”
q Don‘t push: Each truck mixer in the
convoy is guided to the appropriate
pump by the signaller.
Pump (far left) has a somewhat larger
set-up area and can be fed by two truck
mixers at the same time.
6 PM 4307 GB PM 4307 GB
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Franz Syrowatka from betonlift Hamburg
adds: “To us it was clear that we would be
using our Putzmeister 52 m booms; three in
action and one as a stand-by pump with one
machine operator to relieve colleagues during
the day. The important thing for pumps
1 and 3 was the one side support, and that
we have a working area of 180°. This was
the only way that we were able to reach all
corners of the area to be concreted. With
pump 2, we had somewhat more space. We
were able to provide full support there, and
were able to load using two truck mixers at
the same time. This enabled the P2 to reach
a somewhat higher effective pumping rate
per hour.”
An average pouring rate of 180 m³/h was
assumed for the three pumps combined. At
2,650 m³, this meant a pumping duration of
approx. 14 hours. Therefore, concreting was
set to begin early, at 6:00 am. To save some
Title story
p Keeping an overview: Three booms, moving construction site cranes, constant changing of truck mixers – the construction site
requires the utmost attentiveness from the machine operators.
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time, the four concrete pumps were moved
into place the evening before, which meant
that all that remained to be done was to
set up the machine supports and move the
boom into its working position anytime from
5:00 am onwards. Around 5:30 am, the first
Holcim truck mixer arrived from the plant
approx. 15 km away, and shortly after 6:00
am, the first concrete started to flow. In total,
there were 45 truck mixers constantly driving
to and fro, transporting the concrete to
the “<strong>Dancing</strong> <strong>Towers</strong>”.
t A fence reduces the street width
by half: On one side, traffic can pass
by unhindered, and on the other, the
truck mixers control the M 5 , which
is supported on one side. The one side
support (OSS) for pumps 1 and was
crucial for their use in the tight space
available.
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