March 2013 Tube Products International
61
construct ion, bui lding
& structural tubes
Large cold bent tubes for
outdoor opera
After celebrating its century anniversary,
Sopot’s Forest Opera in Poland is
undergoing a huge renovation. The
rebuilding project will see the structure’s
unique location brought together with
21
st
century facilities and one of the best
sound and vision systems in Europe.
The £16.6mn (75mn zł) redesign
contains cold bent arches curved by UK
company Barnshaw Section Benders.
The modernised, open-air amphitheatre,
which sits in the picturesque Sopot
forest, will be covered by a bowstring
structure, shaped by two arches
spanning 90m.
The project involved Barnshaws
bending 16 steel tubes at 1,300mm
cut diameter, which were bent to radii
of 49.785m. Supplied by Interfare Rohr
Union, each tube was 70mm thick, with
the largest section weighing 26 tonnes.
Contractors acknowledge that previous
options of producing structures such as
these were limited to induction bending
or producing the curve by a series of
facets, which is not so architecturally
appealing.
The tubes are claimed to be the
world’s largest ever to be cold bent,
with a strength of 78,95cm
3
, the
equivalent of bending five 914 x
419 x 388kg/m at the same time.
The jobs required a custom-made
bending machine and incredible
forces to bend. In the end, the job
supplied by Barnshaws added up
to £322,000 worth of free issuing
bending. Typical applications for the
machine used by the company’s
expert benders are for stadiums,
roof structures and bridges.
Barnshaws originally estimated
a 22-week delivery date for the
curving of all 16 tubes, on behalf of
German agency Stabikon. However,
the company finished the bends in
just 14 weeks. Barnshaws Section
Benders encourages architects and
clients to involve the company at an
early stage, as limitations of previous
bending capabilities are surpassed by
the company’s acquired new technology.
The company can also curve the entire
range of universal sections, cold bend
tube up to 1,500mm diameter x 60mm
thick, and induction bend up to 711mm
diameter tube.
Established in 1969, Barnshaw Section
Benders is based at six manufacturing
sites around the UK, located in the West
Midlands, Manchester, and Hamilton,
Scotland. Across these sites over 120
specialist machines are housed, and
have provided steel bending services for
some of the country’s largest projects,
including shopping centres, football
stadiums, airports and, most recently,
the Olympics.
Barnshaw Section Benders Ltd
– UK
Jumbo HSS sizes
Atlas Tube has expanded its Jumbo
HSS product line with the addition of
two new sizes of jumbo square hollow
structural sections (HSS).
The company’s Jumbo HSS is available
in a wide range of weights and
dimensions, and is currently offered in
wall thicknesses of 0.5" to 0.875".
Atlas Tube will now also offer 18"
and 20" square Jumbo HSS in a wall
thickness of 0.375".
Uses for Jumbo HSS include vertical
column and diagonal bracing applica-
tions, as well as members of large, long-
span trusses. Jumbo HSS is an option
for solving complex design challenges
for structures with large load demands,
eg structures in high seismic areas.
“We’re happy to expand our Jumbo
HSS line to now offer our customers
more options and sizes to best suit
their specific uses and projects,” said
Jelani Rucker, director of marketing and
business development for JMC Steel
Group, of which Atlas is a division.
Customers may contact Atlas Tube or
one of the following stocking distributors
for ordering information: Kloeckner
Metals (
);
Totten Tubes
); or
Tubular Steel (
.
Atlas Tube
– USA
