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on schedule – underground construction work on Hamburg’s
new three-kilometre S-Bahn (underground railway) line to Hamburg-Fuhlsbüttel
Airport is progressing exactly as planned. Specially designed
for this project by Langenburg-based building machine manufacturer
TEREX Schaeff, two S-18 caisson excavators are making a vital
contribution to the project’s success. Remote-controlled,
they remove rock down to 40 metres underground. Pneumatic
(3.0 bar) shaft sinking prevents ground water from leaking
into the working chamber of the shaft construction. The Hamburg
S-Bahn project is the first operation where the caisson method
is used on this scale.
The two S 18 caisson excavators were specially designed and
built for this operation by TEREX Schaeff’s Construction
& Mining Technology (CMT) division in just six months
and in late March 2004 they were handed over to the contractor,
Arge Flughafen S-Bahn Hamburg. Since August they have proved
their reliability by working non-stop at the Brombeerweg emergency
exit shaft.
Protecting residential buildings near and around the construction
sites was essential for this project. Therefore any groundwater
lowering had to be avoided at all costs. To achieve this,
the engineers of Arge Hochtief and Bilfinger Berger opted
for pneumatic caisson shaft sinking, adding many innovations
to boost the safety of the workers and minimise health hazards.
Over ground they constructed 40-metre blocks weighing up to
4,500 tons, which sink into the ground due to their own weight
as soon as the underground foundation is excavated. In the
chamber at the bottom of the caissons the special TEREX Schaeff
excavators work unmanned at pressures of up to 3.0 bar. In
this case the drivers operate the S 18 excavators by means
of an overground remote monitor in the controls container,
operating them to remove and load the accumulation of sand,
clay, and boulder marl. At lower pressures the driver can
work on site, using the remote control function.
The 12.6x10.6-metre and 13.8x5.4-metre working chambers really
put the caisson excavators’ unusual kinematics to the
test. The S 18’s specially designed 3-piece-articulated
booms can reach any corner of the different chambers and effortlessly
fill the transport buckets, which have to pass through a lock
system on their way from the pressurised area to the top.
After having cut through the solid foundation at the Brombeerweg
emergency exit shaft, the underlying sandy soil now has to
be flushed with water cannons down to the final depth. Currently,
the two TEREX Schaeff S 18 excavators are being prepared for
the second pneumatic caisson section at the corner of Etzestraße/Herschredde.
In this second project, starting in mid-December, they are
expected to carry out the difficult tunnel heading operation
for the second emergency exit shaft just as reliably and efficiently
as they did at the Brombeerweg.
Shield tunnelling for the two 1,800-metre S-Bahn tunnel tubes
on the 3-kilometre route from Ohlsdorf station to the Fuhlsbüttel
airport terminal is due to kick off in early 2005. According
to Deutsche Bahn (German Railway) regulations, Brombeerweg
and Etzestraße must have emergency exit shafts at a
distance of 600 metres. The start and destination shafts of
the shield tunnelling stretch will be converted into escape
tunnels at a later stage. The airport route will cost 240
million euros, just under half of which will be funded by
the city and fifty-one per cent by the German government.
The airport S-Bahn line is scheduled to start operating by
2007.
Text: Thorsten Hiller
More information:
Terex GmbH
Schaeffstr. 8
74595 Langenburg
Phone: 07905/58-0
Fax.: 07905/58-114
info@TEREX-Schaeff.com
www.Terex.com
Two S-18 caisson excavators designed
and built by Langenburg-based building machine manufacturer
TEREX Schaeff are excavating a section of Hamburg’s
new three-kilometre S-Bahn (underground railway) line to
Hamburg-Fuhlsbüttel Airport. Pneumatic (3.0 bar) shaft
sinking prevents ground water from leaking into the working
chamber of the shaft con-struction. Photo: TEREX Schaeff
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