Vertical Shell
Southbank Tower, London

A new sculpture commissioned for the South Bank Tower based on an enlarged fragment of oyster shell found by the artist on the nearby banks of the Thames. The sliced form is constructed from fins of anodised aluminium, that cantilever 10m up from the floor of the lobby of South Bank Tower.

The fins, individually far too slender to be self-supporting over this height, work together to form a stable structure. The sculpture is supported on a hidden base plate concealed within a thin floor finishes build-up, giving the impression that it is emerging seamlessly from the floor.

Creating this artwork required very careful design and 3D modelling of nearly 32,000 individual components.

The 300mm aluminium fins have a depth of only 3mm, with the spacing between them varying from 29mm to 79mm.

There are two types of fixings between aluminium pieces:

a. Splice detail between parts of the same fin: This is a row of nine M5 binding screw-style bolts to appear identical whichever side of the connection is viewed.

b. Spacer between adjacent fins: This is a 24mm outside diameter threaded aluminium tube, fixed to each fin with an M16 stainless steel bolt countersunk into a machined aluminium washer.

Maximum allowable centres between the spacers avoid local buckling and achieve sufficient 'density' of connections which had to increase towards the highly-stressed base. Analysis provided an overall number of spacers to be included in the bottom two metres of the sculpture, another figure for the next few metres up, and a third for the remaining distance to the top.

Completed 2015.

Project Information




Tobias Putrih