Concrete, steel and . . . lofty fruit cake

STRUCTURAL ENGINEER

26-1-1947 - 21-6-2008

NAT Bonacci, whose innovations in structural design contrib-uted to Melbourne's changed skyline over the years, has died of cancer at Epworth Freemasons in East Melbourne. He was 61.

One product he designed for the building industry was named after him; the Bonacci Beam is a portable steel shell into which concrete is poured after it is installed. Well-used examples are the tunnel under the race track at Flemington that is used by horses and vehicles, and at the Curly Flat Winery at Lancefield.

Besides design work on major hotels and many of the buildings along St Kilda Road, he was also responsible for the award-winning undulating curved concrete ceilings in Melbourne City Council's CH2 building. A more recent work, a bridge at Mount Hotham, is to be named after him.

Born in Decollatura, a village in Italy's Calabria region, he arrived in Australia, aged four, with his parents who emigrated after World War II. The family eventually settled in Myrtleford.

From an early age he helped on the family's tobacco farm. Despite growing up surrounded by tobacco, he never smoked.

Nat was an academically gifted student at St Mary's School in Myrtleford, where he dreamt of becoming a train driver. He also acted as interpreter not only for his family but the growing local Italian immigrant community.

He began commuting to Wangaratta Technical School at age 14, and three years later moved to Melbourne, where he completed a diploma at RMIT and an engineering degree at Melbourne University, on full scholarships. A boarder at Newman College, he returned to Myrtleford during holidays and worked for the Ovens Valley Shire, surveying and designing roads.

Nat landed his first post-graduation job when he calculated in his head in an instant the answer to a technical question posed by his boss-to-be. It was the only time he applied for a job.

In 1972, he married Marisa Ammendola, who was from the same part of Italy as his family, and nine years later he co-founded an engineering company in a field dominated by well-established firms. Beginning with a staff of three, the company, now known as Bonacci Group, expanded to its present size of 100 staff in four offices.

Filled with enthusiasm and boundless energy, he had the ability to think laterally when confronted by complex technical problems. And he never shied away from expressing an opinion.

Nat was an acknowledged master of concrete and steel; he always knew the most appropriate system to use in different situations. He was widely consulted by construction companies seeking the best engineering solution possible, not just the standard.

He was responsible for the excavation of almost an entire city block - four levels underground - for Melbourne's Queen Victoria development, designing a system that enabled more expedient excavation.

At Melbourne's Grand Hyatt and Westin hotels, he engineered curved concrete stairs that appear to float. Other engineering highlights include the Menzies at Rialto, Sydney GPO redevelopment, Park Hyatt Hotel, St Patrick's Cathedral restoration, former Shell House, ANZ bank building and BHP Billiton Centre.

He provided engineering advice for unusual requests, too. In the late 1980s, he advised chefs at the Hyatt on structural integrity when they put together the world's tallest (fruit) cake! He also checked that the balcony at the Princess Theatre could cope with crowds dancing during performances of Mamma Mia! In the wake of the World Trade Centre attacks in the United States, the media interviewed him as a structural expert to explain how the buildings collapsed.

Nat recently instigated a road deviation project at Mount Hotham to create a village centre for the mountain resort. As structural engineer for Council House 2, Nat was part of the project team that received the Sir William Hudson Award, the highest for engineering in Australia. The City of Melbourne plans to name a room at CH2 in his honour.

He served on numerous boards and committees, such as the Assisi Aged Care Centre, Mercy Hospital, Caritas Christi, always taking an active role, and generously giving his time and building expertise.

While on the board at Newman College for almost 20 years, he arranged for the corroded sandstone spires on the dome to be rebuilt to the original drawings of architect Walter Burley Griffin, using rendered reinforced concrete to ensure longevity. He was always happy to give friends and acquaintances advice on building issues, and to help with home renovations

He also found time to be a cub and then scout leader and involved himself in the activities of his children. And, he delighted in making his own pinot noir that he called "Nat's Folly". St Kilda was his chosen football team because it shared the same colours with Myrtleford, and he took to skiing at the age of 39

He is survived by his wife Marisa, children Mara, Dana, Nina, Anthony and Leia, and his mother Maria, as well as a brother and sister.

This tribute was prepared by Nat Bonacci's daughters Nina and Dana, and Steve Payne, a director of Bonacci Group.