Mixed-use
NSC 19
May 19
they have been lifted into position in
order to get the best possible high-quality
decorative finish,” says Bourne Steel
Divisional Manager Kevin Springett.
The precast flooring planks are
supported within the steel beam’s depth,
thereby creating a clean, flush and uniform
surface. Because the underside will be
left exposed, the precast planks have been
manufactured with a high-quality finish.
“The challenge for the team has
been to understand the protection the
steel and precast units need during the
transportation to site and installation
in order to manage the expected quality
finish,” says Multiplex Senior Project
Manager Stephen Sebborn.
Adding to the scheme’s industrial
look, all of the services, which will be
accommodated within bespoke cells cut
into the plate girder beams, will also be on
show within the completed building.
As well as fabricating, supplying and
erecting the steelwork, Bourne Steel also
designed and installed the 6m-long precast
planks. A grand total of 4,800 of these
prestressed planks were needed for the
project, with the majority being bespoke
units that could only fit in one particular
location.
“Although the column grid spacing is
regular throughout the scheme, there are
some slight adjustments because of the
shape of the plot and building, and so
there are almost 100 different plank types,”
explains Mr Springett.
“We are also working to some
exceptionally tight tolerances as there is
only 2mm in level between each plank in
the centre of the span.”
Previously, the 80 Charlotte Street site
was occupied by a concrete-framed office
block built around a central courtyard. The
concrete frame is being replaced with a
steel-framed structure, while the original
Whitfield Street elevation is now tied into
and fully supported by the new frame.
“This is a Conservation Area and
the retained façade, as well as being
historically significant, helps the new
building deviate away from being one large
form,” says Mr McColl.
“Brickwork and concrete panel cladding
along the other elevations continue this
design.”
Steelwork for the new 80 Charlotte
Street structure starts at basement level
and then incorporates a double-height
ground floor before extending upwards
to the ninth floor with a uniform grid
pattern.
Using all four of the site’s tower cranes,
alongside one mobile crane during the
early stages of the project, Bourne Steel
erected the steelwork by dividing the main
plot into five areas. 20
FACT FILE
80 Charlotte Street,
London
Main client:
Derwent London
Architect:
Make Architects
Main contractor:
Multiplex
Structural engineer:
Arup
Steelwork contractor:
Bourne Steel
Steel tonnage: 3,200t
Bourne Steel had
the use of four tower
cranes for the steel
erection
Bourne Steel installed
precast planks along
with temporary
propping
/Fabrication#Handling_and_transportation
/Steel_construction_products#Plate_girders
/Fabrication
/Construction#Steel_erection
/Construction#Tolerances
/Facades_and_interfaces#Facade_retention_in_building_renovation
/Construction#Tower_cranes
/Construction#Mobile_cranes