Battling corrosion and a Grade II listing, this offshore cultural centre triumphed over adversity, writes Felix Mara. Photography by Luke Hayes
It would have been sad indeed if White arkitekter’s design for Southend Pier Cultural Centre had gone the way of fellow Scandinavian Snøhetta’s doomed Turner Contemporary in Margate. Both were formally ambitious and both were set in treacherous offshore environments; however White’s amenity eventually materialised on the deck of the world’s longest pier - a frail cast-iron structure - and opened in September, whereas Snøhetta’s dramatically overshot its budget and vanished in a storm of accusations and controversy.
Despite its warped roof and inclined walls, the Southend project was ultimately buildable and, working with executive architect Sprunt, White arkitekter made the necessary compromises to its competition-winning ‘sculpted by wind and wave’ concept. The proposed amphitheatre, integral to the idea of an offshore public space extending Southend’s urban realm, was sacrificed. However, the large internal space for exhibitions, performances and other events remained, along with the idea of a homogeneous finish to external walls and roof planes.
The existing fabric of the pier, now listed, which first opened in 1830 and was extended to a length of 1.34 miles 18 years later, had to be handled with extreme care. The corroded bracing, deck and supporting steel were removed below the pier-head site of the new pavilion, which rests on new steel carrier beams installed between existing 100-year-old piles. These piles were not surveyed, so the project team had to estimate their load-bearing capacity by evaluating archive photographs of buildings they once supported, which no longer exist, and loading from the pavilion was evenly distributed by its fully welded steel box section trussed plinth.
‘Bolts would have rusted away and box sections rust more slowly,’ says Price & Myers project engineer Emmanuel Verkinderen. ‘But the bolted structure sitting on this plinth, designed to be erected as quickly as possible, includes other section types.’ Flooding in the high tides of the Thames Estuary was also a concern, so the pavilion sits 1.5m above the pier deck.
The critical strategic move, which impressed the competition judges, involved fabricating the pavilion’s 170-tonne steel frame as a complete assembly, along with 75 per cent of its external envelope, 23 miles up-river at Tilbury Docks, then barging it to site and craning it into place at high tide in the spring, with supports at only four points. This minimised the time spent working in a tidal, windswept, corrosive marine environment.
Although Sprunt modelled the pavilion in Revit, this was not a textbook BIM project. ‘We began the Revit model at Stage E and most of the construction build-ups were worked out on site, rather than digitally,’ says Sprunt project architect Josef Kolar. ‘We also exported two-dimensional AutoCAD files for use by other project team members.’
But Price & Myers relied heavily on a different form of three-dimensional digital modelling; it used Dassault Systèmes CATIA and Digital Project to simultaneously design and simulate loads and exported data for finite element analysis, for example, of the star configurations of tapered I-beams in the roof structure, which the architect wanted to appear as thin as possible, with a faceted upper surface and soffits. These members direct loads towards the roof’s centre, where they are deeper and services penetrations through their webs reduce their weight as well as stress. Avoiding beams behind floor-to-ceiling windows was also established as a rule. ‘Simultaneous design and analysis allowed more feasible design options to be explored in a shorter space of time,’ says Verkinderen.
Price & Myers’ model was also used to calculate the location and centre of balance of the lifting sling used to crane in the assembly, ensuring structural integrity and horizontal alignment, as well as detecting clashes. This model was also intended as a reference point for fabricators, architects, crane operators and others.
Price & Myers’ model did not drive conceptual form-finding. ‘The form was worked out at the beginning,’ says Kolar, but it was vital at that most critical stage of the project when structure and construction were rationalised. At this stage, different but visually similar finishes for external walls and the roof were also adopted. These walls have GRP cladding with an aqueous quality by day, which changes tone: it appears white in bright sunlight but greenish-grey under overcast skies. The roof is treated with a non-slip textured top coat, colour-matched with the walls.
While certain aspects of the design such as concealed gutters and downpipes were being refined, major programme and budget risks were designed out, enabling White arkitekter’s imaginative idea to become a reality.