roof is tapered from 900mm to 1,300mm
deep at the centre, and has 80mm flanges.
Meanwhile, the roof steelwork is doing
two jobs, as well as spanning the void
between the existing buildings, it also
supports a new column-free upper level of
the development.
As Severfield Project Manager Dominic
Charlton explains: “A new suspended
floor is hung from the bottom chord of
the ribbon trusses. It is constructed from
tapered composite beams, with a 150mm
slab over the top. At one end the floor beams
are supported on new structure within the
footprint of the existing coal drops buildings,
while at the other end, it is supported by
solid steel hangers.”
Mr Bateman adds: “As well as providing
small and light elements for the long span,
steel made it straightforward to collaborate
in 3D between the design team and
contractor, which was vital in this case due to
the complexity of the geometry.
“The major components were all
fabricated offsite, brought to site in
individual sub-assemblies and bolted
together at ground level and lifted into place,
maximising both safety on site and quality of
the finished product.”
In summary, the judges say the kissing
roof that links the two original Coal Drop
A W A R D SSDA 2019
buildings led to a solution of three steel
bowstring frames all working together,
shaped to reflect the ribbon roof. New
exposed steel at deck level is extremely
well integrated and carefully detailed to
be in keeping with the original structure,
strengthening and extending it to suit its new
purpose.
NSC 17
October 19
Photos on this spread © Simon Kennedy
FACT FILE
Architect: Heatherwick Studio
Structural engineer: Arup
Steelwork contractor: Severfield
Main contractor: BAM Construction
Client: King’s Cross Central Limited Partnership
© John Sturrock
© John Sturrock
/Composite_construction#Types_of_composite_beam
/The_case_for_steel#Offsite_fabrication_for_precision_parts
/Health_and_safety
/Fabrication#Quality_management
/Visually_expressed_structural_forms