A complex sculpture, supporting six Porsche sports cars, is an exemplary application of steelwork efficiency and design.
A selection of six valuable cars, suspended from an intricate and complex steel sculpture, provided one of the highlights of the 2023 Goodwood Festival of Speed.
Containing 40t of steelwork, the Porsche Sculpture was installed to commemorate 75 years of the German manufacturer’s sports cars.
Standing 25m-tall, the cantilevered structure included three interconnected hoops and six spars that supported the Porsches, which ranged in age from a 1951 model up to and including a contemporary car.
Award: The Porsche Sculpture at 2023 Goodwood Festival of Speed
- Artist: Gerry Judah Ltd
- Structural engineer: Diales
- Main contractor: Littlehampton Welding Ltd
- Client: Goodwood Festival of Speed
Designed, fabricated and installed within a tight 28-week delivery timeframe, the structure presented numerous challenges.
“The technical challenges were all related to the complex geometry and achieving the required aesthetic quality. The central hub is a dodecahedron that needed to interface with 12 tubes of two different diameters,” explains Diales Associate Director Bruno Postle.
“The hub required the necessary strength to transmit all of the loads, while also being buildable with all interfaces positioned at the correct angles and locations. It also needed to look good.”
Steelwork was the natural choice for the sculpture as no other material could provide the same combination of strength, affordability and adjustability.
Steel’s ability to be reworked allows it to be shaped into the necessary complex forms required for the sculpture. While alternative materials could theoretically have been used, they would not have provided the same strength and would be vulnerable to impact damage, while lacking the adjustability needed to create the required forms.
Another engineering challenge was developing a stable cantilevered structure, with a low mass distribution at height, that would manage dynamic response.
Dynamic loads, such as those produced by gusts of wind, will introduce twisting forces to a structure if its centre of mass and stiffness do not coincide.
Variable thicknesses of the structural elements (20mm plate at critical junctions, tapering to 4mm plate in less stressed areas) optimised the weight and distribution of the sculpture.
The sculpture was fabricated in Littlehampton, only 15km from the installation site. The compressed timeline required concurrent design and fabrication, with late design changes needing to be implemented during the production process.
“The sculpture, which displays a number of original Porsche sports cars on cantilevered arms, exemplifies the extraordinary flexibility of steel as a material. It is a visually exciting, dynamic form that has been cleverly engineered, carefully detailed and skilfully fabricated – the result of a true team effort.”
Once the fabrication process was complete, the entire sculpture was trial assembled in order to make sure every part fitted together exactly. It was then disassembled and transported to site.
The hoops, which were too big to be delivered to site as complete pieces, arrived onsite in three sections. The spars, with the longest measuring approximately 16.5m-long, arrived pre-assembled in single pieces.
Once they were at Goodwood, the sections were re-assembled, using a custom-designed rigging system and two cranes, which were required to complete the precise positioning of the sculpture’s steel elements.
To maintain the structural stability throughout the erection programme, the base and hub were installed first, then the spars with their pre-attached vehicles and finally the suspended hoops.
After the festival, the sculpture was disassembled in the reverse order of assembly. It is now in storage, awaiting its next festival appointment.
Produced by BCSA and Steel for Life in association with Construction Management.
