Design Awards: 2008: Certificate of Merit

East Beach Cafe, Littlehampton

East Beach Cafe

Designer

HEATHERWICK STUDIO

Structural Engineer

ADAMS KARA TAYLOR LTD

Steelwork Contractor

LITTLEHAMPTON WELDING LTD

Main Contractor

LANGRIDGE DEVELOPMENTS

Client

BROWNFIELD CATERING

The East Beach Cafe is a south-facing single storey building on the seafront in Littlehampton. The building has a narrow footprint determined by the dual constraints of the promenade at the front and the public car park running along the rear of the site. The southern façade is predominantly glazed to afford the maximum views from the café to the sea, whilst a level of interest and detail has been achieved on the rear of the café by the rippling form.

The shell of the building provides both its skin and structure, comprising a steel shell formed from horizontal ribbons which are curved around a series of vertical slices. This ‘monocoque’ steel shell in which all parts act together is similar to the hull of a ship.

The exposed seaside location subjects buildings to heavy weathering, with the high salt content of the air speeding the natural degradation of all materials. With this in mind, the designer opted for naturally finished materials that respond to the local environment. The 8mm thick mild steel shell that forms the outer skin was initially allowed to rust to gain texture, colour and character. Once the surface had weathered, an oil based coating was applied to halt and inhibit any further corrosion.

The shape of the building is informed by the ways in which steel can be manipulated; jigsaw-puzzle like pieces were precision cut by machine and used as a template for curving ribbons formed and welded within the controlled environment of Littlehampton Welding’s workshop. The structure was modelled using a finite element design package, with the designer’s digital 3D model of the complex geometry directly imported into the analysis model. This allowed the inherent stiffness of the sculptural shell to be modelled with the latest digital analysis methodology partly developed at AKT. The model was used to identify those areas of the shell where the curvature was not sufficient to provide the required stiffness. A series of 150mm deep steel ribs were then introduced at regular centres to stiffen the structure. The glazed wall facing the sea is articulated by a series of columns fabricated from steel plate which incorporate rainwater pipes, glazing frames and shutter guide rails. The shell was prefabricated, dismantled and then brought to site in four sections, which were then subsequently welded together.

As a single storey building the resulting foundation loads were relatively low, and simple economic strip foundations were adopted, bearing onto the sand below. The lateral loads resulting from the shell behaviour are resisted by the in-situ topping to the beam and block ground floor slab.

Judges’ Comment

s:

This unique structure is largely formed of steel plates welded into a series of “wave” shapes forming an irregular shell. Situated at the top of the beach, the exterior is reminiscent of wave-shaped rocks, whilst the interior is rather like a cave. Clearly the ongoing protection of the shell will be crucial to maintaining its future effectiveness.

The project is already enlivening this part of the seafront. The high quality of the extensive shaping and welding has been key to this extraordinary and successful project.

Transfer Structure, Baker St, London

Transfer Structure, Baker St, London

Architect

MAKE ARCHITECTS

Structural Engineer

EXPEDITION ENGINEERING

Steelwork Contractor

WATSON STEEL STRUCTURES LTD

Main Contractor

HBG CONSTRUCTION LTD

Client

LONDON & REGIONAL PROPERTY LTD

This new structure, presenting a stunning visual statement within the main reception area of the newly refurbished 55 Baker Street, must be one of the most striking examples of how a complex structural solution is needed to produce a seemingly simple architectural concept.

The architectural requirement was for a slim, elegant, angular structure to replace 12 original reinforced concrete ground to first floor columns and present a dramatic backdrop to the reception area.

It was recognised at the outset that the design and engineering of the transfer structure was extremely complicated and a key part of the project. It was essential that a steelwork contractor be brought on board very early in the design process and this was facilitated by a two stage tender process where Watson Steel Structures was appointed, initially based on a set of budget rates and the lump sum fixed price contract was finally agreed once the design was substantially complete.

The client purchased these conventional 1960’s concrete framed office blocks with the intention of creating a single, modern, multiple use building. Rather than demolish the existing buildings and start again it was decided, for programme and economic reasons, to retain the basic concrete frame and replace all the external and internal walls to suit the new uses. Whilst the existing column spacing of 14′ x 14′ (4.27m x 4.27m) was adequate for the client’s use in the general areas, in the main lobby area he wished to have an open, column-free space.

The project involved temporarily propping the concrete frame above, removing 12 of the existing concrete columns, installing the new steel structure and then transferring the load from the floors above to two existing basement columns below.

The transfer structure is in a highly visible area and the architectural requirement was for it to appear as a ‘sculpture’ rather than a conventional transfer frame. The members were therefore required to be as slim as possible with a high quality finish.

There are two separate identical connected structures, mirrored about the centreline of the building, each with four cantilever arms and two stubs that support the floor above and an inclined column down to a single base plate. The legs which each carry an ultimate load of 1200 tonnes are tapered down to just 300mm x 600mm and formed from eight plates which are almost a solid cross section at the base plate level. The arms are tapering box sections fabricated from plates up to 80mm thick whilst the columns are double webbed I sections with additional external structural cladding plates designed to cope with the high stresses involved.

Special attention was paid to the visible connection details between the individual plates, their edge profiles and connecting weld sizes and appearance. A mock up of the column section was produced during the design development stage to allow the architect to define any shadow gaps he wanted to be visible.

Judges’ Comment

s:

Largely hidden within the elegant exterior shape of these transfer structures is an outstanding example of welded fabrication. The technology and craft skills required to weld such thick plate, in such a complex structure, are a great credit to the steelwork contractor. The propping of the existing building, the removal of concrete columns and the transfer of the loads, represents a considerable engineering achievement.

There is no doubt that this challenging fabrication is crucial to the project’s success.

Constructionarium, Mini-Gherkin, Norfolk

Constructionarium, Mini-Gherkin

Structural Engineer

EXPEDITION ENGINEERING

Steelwork Contractor

CAUNTON ENGINEERING LTD

Main Contractor

JOHN DOYLE CONSTRUCTION LTD

Client

IMPERIAL COLLEGE LONDON

The mini-Gherkin project resonates with anyone who knows about the Constructionarium – it is a hit with everyone and makes everyone smile. One of the main benefits of the Constructionarium can be described as ‘engineering delight’. When combined with the popularity of the original Swiss Re Tower (The Gherkin) in London, the delight associated with the Constructionarium’s mini-Gherkin is intense and infectious. It has generated a feel-good factor amongst a key group who are essential to the future of steel engineering: the next generation of civil engineers, builders and steelwork contractors.

Imperial College London needed a steelwork contractor who would be willing to donate the steel and fabricate it for their 4-storey version of The Gherkin tower for the benefit of a major engineering education initiative. The initial drawings for the tower were designed by Expedition Engineering, structural engineers, whilst the construction site supervision plus supply of most other materials, plant and equipment was to be by John Doyle Construction Ltd. The Gherkin project had been in mind for a long time but steel fabrication and erection expertise was needed to make it feasible for a short, sharp Constructionarium student experience.

This project is an educational project and addresses the need to minimise waste. The ability to use and re-use the ‘project kit’ for the mini-Gherkin makes it highly attractive as an environmentally-friendly educational project. The main waste associated with the project is the need to demolish the concrete foundation that the students lay for the steel tower, although the national steering committee for the Constructionarium is addressing improved ways to deal with such waste, through recycling as aggregate or use in landfill. The student project is intended to be constructed, dismantled and reconstructed, time after time. The steel has been treated to assist its durability and exposure to weather. The ‘kit-building’ aspect is intentional in that it allows the structural steel to be stored to maximise durability.

Benefits achieved by using steel construction:

  • Steel tower in kit form, ensures a large structure can be built in days
  • Trial erection at Caunton’s factory meant that Caunton, Imperial and their main contractor partner, John Doyle Construction, could rehearse what the students would be doing and anticipate difficulties
  • The simplicity of the steel erection process means that the challenge to the students can be increased by giving them a larger scale of structure to build: the four-storey (12m) structure is double the height of the previous tallest freestanding structure built at the Constructionarium
  • The large scale of the project, by student standards, means that students were faced with real issues of working with cranes, scaffolders and the need to get the first stage (setting out and laying foundations) correct within the steel tolerances

The fabrication was carried out by Caunton’s Apprentices, based in the Caunton Engineering Academy, and the challenge proved a marvellous opportunity for the Academy to hone and show its skills.

Judges’ Comment

s:

This construction “kit” of tubular steelwork, replicates the frame of the “Gherkin” building in London. The steelwork contractor donated the steel which was fabricated in his apprentice academy, and Imperial College and the NCC have nurtured the scheme. Undergraduate training in the hands-on management and execution of projects is now supported by an increasing number of universities.

The steelwork itself is modest, but the spin-off from this novel initiative is impressive and praiseworthy.

Singing Ringing Tree, Burnley

Singing Ringing Tree

Architect

TONKIN LIU LTD

Structural Engineer

JANE WERNICK ASSOCIATES

Steelwork Contractor

MIKE SMITH STUDIO

Main Contractor

MIKE SMITH STUDIO

Client

BURNLEY COUNCIL

The Singing Ringing Tree is a musical sculpture in the landscape, constructed of stacked mild steel pipes of varying lengths, which sits on the top of a hill above Burnley, in Pennine Lancashire. From a structural perspective the project is a very small but highly complex sculpture, designed on a modest budget.

Singing Ringing Tree takes the form of a tree bending to the winds and harnesses the energy of those winds to produce a low, tuneful song. Previously occupied by a derelict brick shed and radio mast, the Crown Point site is now defined by an enigmatic sculpture which sings into the landscape, animating this dramatic location with song.

Singing Ringing Tree is completely selfsupporting. It is constructed of structural and musical tubes made from mild steel, a material that can be welded cheaply but is sufficiently heavy to ground the asymmetrical form and prevent it from toppling. Galvanised steel was chosen because it is strong, stiff and durable and therefore able to withstand the rigours of a site that in extreme cases can be vulnerable to wind speeds of 160 km/h.

The weight of each layer is transferred by steel rings which act to tie the tubes in each plane to each other and provide a load path down to the foundation of the sculpture. The slight horizontal rotation of layers provides horizontal in-bracing.

The structure has been designed to tolerate people climbing on it and to withstand snow and extreme wind loads.

The sculpture is an asymmetrical doublecantilevered structure incorporating 320 pieces of galvanised steel pipe divided into 21 layers. Steel circular rings of varying sizes define each layer and support a plane of parallel pipes spaced 200mm apart. The length and number of the pipes also vary, and fill in an oval on plan. It is towards the top of the sculpture that the 25 pipes which produce the sound are positioned.

Tubes vary in length and diameter to create a range of musical chords, and are arranged in a regular rhythm of layers. Each layer differs from the next by a 15 degree horizontal shift, creating an asymmetrical sculpture in the round, which responds to the changing wind directions. To create flutes that would tune the sound made by the wind, slots were added to the underside of 25 pipes.

The structure is at its narrowest – 1.2m – in the middle, and this is where the stresses in the structure are the highest. Computer models were used to calculate how the lines of force would transfer through the structure’s layers, rings, bolts and pipes.

It took only two days for the prefabricated steel pipes and rings to be bolted into place on site. The steel has been galvanised to prevent rusting, giving a highly reflective shimmering surface which will dull over time, to yield a softer reflective patina.

Judges’ Comment

s:

This is sculpture in a structural form, being one of a series of “Panopticons” intended to inspire renewed interest in this part of East Lancashire. The asymetrical form may be likened to a windswept tree, which sings and rings in the wind. The galvanised tubes are welded to rings, assembled in layers and some are slotted, generating an eerily mournful sound.

The Singing Ringing Tree is beautiful and evocative, and as a landmark it is an appropriate use of steel.