Design Awards: 2011

Riverside Waste to Energy Plant, Belvedere

riverside_waste_02

Architect

Jacobs Engineering UK Ltd

Structural Engineer

Jacobs Engineering UK Ltd

Steelwork Contractor

Bourne Steel Ltd

Main Contractor

Costain Group PLC

Client

Cory Environmental LTD

Museum of Liverpool

museum_of_liverpool_01

Design Architect

3XN Architects

Delivery Architect

AEW Architects

Structural Engineer

Buro Happold

Steelwork Contractor

Caunton Engineering Ltd

Main Contractor

Pihl/Galliford Ltd

Client

National Museums of Liverpool

Bridge GE19, East London Line

ge19_bridge_01

Structural Engineer

Benaim

Steelwork Contractor

Mabey Bridge Ltd

Main Contractor

Balfour Beatty-Carillion Joint Venture

Client

Transport for London

The Point, Lancashire County Cricket Club

the_point_02

Architect

BDP

Structural Engineer

Capita Symonds Structures

Steelwork Contractor

Watson Steel Structures Ltd (Severfield-Rowen PLC)

Main Contractor

Morgan Sindall

Client

Lancashire County Cricket Club

New South Bridge, A406 Hanger Line

new_south_bridge_01

Structural Engineer

Hyder Consulting Ltd

Steelwork Contractor

Cleveland Bridge UK Ltd

Main Contractor

Vinci Construction UK Ltd

Client

Transport for London

North Stand Redevelopment, Leicester Tigers

tigers_stand_02

Architect

AFL Architects

Structural Engineer

WRS Corporation Ltd

Steelwork Contractor

Caunton Engineering Ltd

Main Contractor

Galliford Try

Client

Leicester Football Club PLC

New Cross Gate Flyover, East London Line

new_cross_gate_01

Structural Engineer

Scott Wilson

Steelwork Contractor

Mabey Bridge Ltd

Main Contractor

Balfour Beatty-Carillion Joint Venture

Client

Transport for London

The new East London Line is an overground line which runs north to south through the East End, Dockland and South areas of London. In December 2007 the line was closed for an extensive expansion project to take place which would include the overground network. It was forecast that 35.4 million passengers per year, an increase from 10.4 million, would use the line following completion of phase one of the extension plan.

The contract included new stations and large truss bridges and was scheduled to be opened in June 2010. Part of the contract was to fabricate and erect a £5.9 million package which included the bridge and approach span at New Cross Gate.

The flyover, north of New Cross Gate with a total of 690 tonnes of steel, allows trains to run through to West Croydon crossing over the Network Rail London to Brighton Line. Carrying a single rail line, 75m long and 8m deep, the Warren Truss structure comprises eight longitudinal main girder sections, each 20m long and weighing between 20 and 25 tonnes and 37 crossbeams 10m long and each weighing three tonnes. The side trusses were formed by the main girder sections: 36 diagonal beams six metres long and each weighing between two and four tonnes and 12 top members all varying in length and weight.

A close relationship was formed between the steelwork contractor and the main contractor to achieve the most cost effective solution, putting forward value engineering alternatives which would improve the scheme and ensure the best outcome. For the approach span, it was recommended that 8mm leg length fillets be used instead of 12mm fillets, offering a substantial saving to the fabrication price.

As an alternative to the erection method for the main span it was suggested that a very large crane could be used to lift the pre-assembled deck into place. It was concluded however, that the original tender option would be used due to the lift weights and available space for a crane platform.

All the steel was approved to BS EN 10025:2004 standards as per specification. The bottom chords and associated cross girders were provided from weathering steel and the remainder of the structure was painted with Network Rail N4 Paint System.

The bridge steelwork was trial erected at the steelwork contractor’s fabrication facility and the deck crossbeams were machined to length ensuring the correct fit within the end plate connections. The steelwork was delivered to the site and, with a planned closure of the busy line at New Cross Gate on 10 May 2008, a pre-possession assembly took place adjacent to the tracks. The steelwork forming the deck and the top chord of the truss was assembled and the whole structure fully bolted. The deck was cast and once it had achieved sufficient strength, the structure was jacked up approximately six metres high to enable a self propelled modular transporter (SPMT) to be positioned underneath.

In order to transport the structure slowly across the four lines it was necessary to cover the lines with a track protection. Once in place the structure was rolled across the tracks and lowered into position over the bridge abutments.

The extension is expected to play a major role in transporting people to and from the 2012 Olympic Village.

Judges’ Comment

All the challenges of constructing a large bridge over a key rail route, with numerous site constraints and to a very tight timetable, were successfully addressed here. The team and client developed a Warren truss design, with the structure and deck being driven and jacked into place.

The judges were impressed by this solution to a very difficult logistical problem.

2010 Festival of Speed Sculpture, Goodwood

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Architect

Gerry Judah

Structural Engineer

Capita Symonds

Steelwork Contractor

Littlehampton Welding Ltd

Main Contractor

Littlehampton Welding Ltd

Client

Gerry Judah for Alfa Romeo

The Goodwood Festival of Speed is one of the world’s biggest and most diverse celebrations of the history of motorsport. Featuring famous cars and famous drivers, the festival is an unrivalled social and sporting occasion in the motor racing calendar.

A new sculpture is created for the festival each year and is only on display for three days as the centrepiece of the Festival of Speed. After the Festival it is dismantled and moved to the Goodwood Sculpture Park – where it has a new woodland setting, painted a different colour and without the cars. The result is a permanent installation providing pleasure for years rather than a throwaway item discarded after use.

The innovative display – sponsored by Alfa Romeo to celebrate the company’s centenary – was designed especially for the event by renowned sculptor Gerry Judah. The structure’s design, which is reminiscent of the car giant’s Quadrifoglio badge and the red livery of its racing cars, features an Alfa Romeo P2 (a P2 won the inaugural Automobile World Championship in 1925) and a 2003 8C Competizione. The cradles were designed to suit each car and to have a virtually hidden connection between the car and supporting structure.

Standing at 18.5m high and 25m across, the sculpture is made from 12 tonnes of steel. Although it appears to be 175m of continuous tube twisted into position, it actually consists of 32 precision sections of 323.9mm diameter steel. The steel sections also had to fit together seamlessly first time, with no opportunity for mistakes or second chances.

To succeed as a sculpture, the structure had to be a perfect continuous loop without visible joins or sudden changes in direction. To achieve this, the geometry was created using a 3D CAD variation of an old draughting technique for constructing five- centre masonry arches. This provided visual perfection and allowed the structure to be assembled from 32 fixed radius rolled tubes, in turn this meant the sculpture as a whole was practical to assemble, check and prefabricate.

Even so, several splice connections had to be made on site, for this the steelwork contractor and erector of the sculpture developed an ingenious adjustable bracket that provided alignment, structural integrity, and allowed three-axis adjustment before the sections were finally welding together.

Each of the two loops is nearly 80m of 323.9 CHS and weighs six tonnes, so there needed to be eight additional connections between the tubes where they touch, taking advantage of the way the tubes turn in on themselves to provide self-bracing of the structure as a whole. Each of these connections consists of a 125mm diameter bar completely concealed and inserted. The setting out of the holes for these pins was a critical part of the workshop fabrication. In order to get the pins through the pre-drilled holes in the tubes, a screw-on point was used so the pin became a giant drift.

The final result is a monumental sculpture consisting entirely of what appears to be two perfectly seamless lengths of steel tied into a huge bow by a giant.

The structure could only possibly have been made from steel – nothing else provides the strength, durability, flexibility and simplicity of construction to go from final design approval to finished structure in less than three months.

Judges’ Comment

In spite of its striking doubly-curved appearance, this ingenious steelwork sculpture is actually formed of singly-curved tubular sections. Temporary bolted connections were removed when the high quality welded joints were completed.

Excellent fabrication and accurate erection have created a seamless shape in the sky. A tribute to the finesse achievable with steelwork.

River Suir Bridge, N25 Waterford Bypass

river_suir_bridge_01

Architect

Yee Associates

Lead Engineer

Ove Arup & Partners Ltd

Structural Engineer

Carlos Fernandez Casado, SL

Steelwork Contractor

Mabey Bridge Ltd

Main Contractor

Bam-Dragados Joint Venture

Client

CRG Waterford Ltd

For over 40 years Waterford City Council had considered providing a second bridge for the City of Waterford over the River Suir. In 1997 it was concluded that, in addition to a river crossing, a new bypass was required which would connect Cork to the port of Rosslare.

A cable stayed bridge was the favoured choice of construction for the crossing as there would be no need for piers. It also provided the option to use reduced thickness decks offering a navigation clearance of 14m – a necessary consideration in a busy shipping area. Time and cost would also be reduced as the decks could be progressively suspended on the cables rather than using temporary supports in the river.

The asymmetrical twin fan of cables used to support the 230m main deck would enhance the 100m centerpiece, an inverted Y-shaped tower planned to stand on the west bank of the river. This 465m long bridge would become the largest span bridge in Ireland and a landmark structure for Waterford City.

Value engineering input assisted with design and build issues faced during the manufacture stage. Changes were recommended, eg all connections of the cross to main girders from welded to bolted joints, which proved to be substantially more cost-effective and reduced the site programme from 12 to eight weeks; erection changes, from using a floating barge craning all the front span decks into position to the decks being erected from behind at deck level reducing installation costs.

The ladder deck structure carrying the dual carriageway road was made up of 80 main girder sections, each approximately 18 tonnes. The fabrication of the main girders for the cable supported section included some elements of complex geometry in the hanger locations. With large welds and complex angles, dimensional control in these areas became critical. Two box sections at the north abutment, each approximately 170 tonnes, were manufactured in the workshop in segments and welded into full lengths at ground level on site. 102 cross girders, each approximately 10 tonnes, were made in full lengths of approximately 20m. Due to the width of the road deck, and to maintain as low a deck weight as possible, the tops of the cross girders were profiled to follow the road camber.

To protect the 2,800 tonnes of steel required for the decks, a Glass Flake Type II Epoxy treatment was recommended and is ideally suited to bridges.

The structure was erected in two main stages. Firstly the back span, erected from ground level with mobile cranes onto trestles up to the central pylon. The deck was subsequently completed with a precast concrete slab up to the pylon which enabled the front span to be erected in cantilever from the pylon using a modular technique. Each module, comprising two main girder sections and cross girders would be delivered piece-small up to the erection crane sited on the cantilevered end of the deck. Over a seven day cycle each module was erected, the cables installed, pre-stressed and the precast concrete deck positioned. In conjunction with the modular build, a supported section of the front span would be erected of which the largest components were the box sections at the north abutment. These were lifted into position using the UK’s largest available floating crane. These sections were supported on an arrangement of trestles and header beams prior to the front span connection being made and subsequently jacked down into the final position and the trestling removed.

The N25 Waterford Bypass was opened 10 months ahead of schedule on 19 October 2009.

Judges’ Comment

A high-profile cable-stayed road bridge, this helps to generate pride in the community.

The complicated arrangements of the multi-national design team presented a real challenge to the experienced steelwork contractor. Perseverance and the pursuit of practicality in the detail design and construction have resulted in a fundamentally elegant bridge which satisfies client and users.