A winning balance between engineering and heritage needs Wednesday, 11 November 2015

Exsto Management Tasmania’s structural design solution for the Port Arthur Historic Site took out both the Engineering Excellence Award and the Lend Lease Project of the Year Award at the Fourth AIQS Infinite Value Awards.

The Australian Institute of Quantity Surveyors recently announced the winners of its AIQS Infinite Value Awards, recognising winners and participants for their exceptional contribution to the Australian and global construction industry.

According to AIQS CEO Grant Warner, the awards celebrate outstanding projects, great people, work and organisations who lead the way in the global construction industry in delivering innovative projects on time and to budget, thanks to exceptional leadership and attention to detail.

“The calibre and talent of our Award winners demonstrates the strength of our industry,” Warner said.

Exsto Management’s Port Arthur Penitentiary Precinct Conservation project saw the company creating a structural design solution for the site, in order to improve overall structural sufficiency, enable public access and provide protection against storm and sea wave impact.

The famous Port Arthur Historic Site in south eastern Tasmania is Australia’s most intact 19th century convict settlement. Within the site, the Penitentiary is the largest structure, and was originally constructed between 1842 and 1845. While historically significance, the structure faced issues with its stability over the years.

In the 1980s, a conservation program attempted to stabilise the structure, but in 2010 this program was deemed inadequate. Reports found that the walls were at risk of collapse, and thus needed further stabilisation.

Exsto Management had to stabilise the structure, while balancing the need for minimal intervention to the heritage fabric, in a manner compliant with the Australian Building Code and Australian Standards.

It had to also enable public access to the site, with features within the project designed to provide visitors with enhanced understanding of the site, through exposure of fabric and interpretation.

According to the company, engineering requirements for the project came second to the various archaeological, historical and architectural goals. This required innovative engineering to ensure that the structural supports would not overwhelm the structure, or obscure the form and materiality of the existing building.

Exsto Management had to develop a set of clear design objectives that could guide the project team in pursuit of an appropriately site-sensitive design solution. The aim was to create engineering solutions that were “invisible”. The team conceived of a set of structural elements or tools that were tailored to the location and the fragile nature of the building. Each tool was developed individually for customised application.

The engineers then used the tools in multiple forms and variance to test for a solution. With the help of modelling, the engineers found a combination of elements that would provide an acceptable level of structural support, while adhering to the design parameters.

By combining these structural elements together under load conditions, the engineers provided the appropriate structural capacity and restrict, while ensuring the new structures did not overly intrude on the existing building.

The structural design solution not only stabilised the building without impacting over-much on the existing aesthetics, but will also serve as a foundation for a future program of interpretation works, which will communicate to visitors personal stories of convicts and civil officers who worked and lived within the building, in a collated permanent exhibition of models, samples, video footage and photographic records.