Identities revealed: Who executed SA’s notorious River Torrens bridge prank?

After decades of mystery surrounding one of South Australia’s most notorious stunts involving a car dangling from a bridge, the culprits are finally revealing their identities.

After decades of mystery surrounding one of South Australia’s most notorious stunts involving a car dangling from a bridge, the culprits are finally revealing their identities.

South Australians opened their evening newspaper on August 7, 1971, to the image of a FJ Holden hanging from the steel footbridge spanning the River Torrens near Adelaide University.

It was the stunning result of a university prosh week prank executed by well-disciplined engineering larrikins under the cover of darkness.

One quickly undone as university students crossing the bridge that morning upset carefully calculated tensions, their weight prompting a vital chain to snap and sending the car plunging into the water below.

Engineering students behind the Adelaide University prank to hang a car from the footbridge reveal their identities. Picture: Adelaide University's Lumen magazine.

Now the secret posse behind the stunt has emerged after the university’s Lumen magazine editor Mark Douglas recently drew them together for a recent pranksters reunion as part of the institution’s 150th year celebrations.

Many of the 20 involved, now in their 70s, gathered from all over Australia to retell the story of their meticulously planned mission on Victoria Drive that became part of student folklore.

Among them was Wayne Groom, who was Adelaide University Engineering Society president at the time and Hamish Robson of Hawthorndene who was the society’s secretary.

“A group of mechanical engineering students had been planning this for three or four months before they brought the civil engineers in,” Groom, 74, tells the Sunday Mail.

“Hamish came to me and said ‘we’ve got this plan to hang a car under the bridge and he said ‘can we get your approval to do it?’ I thought about it for 23 seconds and said ‘yes, do it’.”

University students check out the FJ Holden motor car hanging from the Adelaide University footbridge, as part of an orientation week stunt. Picture: A student publication from 1971.

Engineering students behind the Adelaide University prank to hang a car from the footbridge have finally revealed their identities (Photo has been digitally altered). Picture: Adelaide University's Lumen magazine

From there the elaborate plan was set in motion. A car was sourced and its motor removed so a group could discreetly drop the prank’s centrepiece near the zoo in daylight.

As night fell the engineering students emerged in the darkness, ready to execute the idea first flagged by engineering student Ross Patterson.

Patterson wanted to emulate a similar car hanging executed at Cambridge University in England during the 1960s.

“We posted a number of people around the place with torches so that they could be used to signal us if a police car was around and we would all lay down low on the ground until it passed,” Wayne says with a laugh.

“We finished the job at about midnight and we all went home exhilarated.”

Wayne blames a group of architectural students for undoing their work, claiming they placed a makeshift fence in the middle of the bridge as part of their own “Prosh Day” pranks.

As numbers swelled on the bridge the students blocked from crossing began to bounce the bridge structure, shifting the “impact loading”.

“Someone got word that there was a car hanging off the bridge and luckily went out there and took a photograph of it before it fell or no one would have ever seen this beautiful image,” Wayne says.

In contrast to the expected crackdown on a bridge prank these days, the group says authorities checked the famed Popeye boat could continue traversing the water safely and after some investigation let the matter drop.

It wasn’t until a few years later when the city council was cleaning up the River Torrens that officials went hunting for someone to help pay for the car’s removal - but to no avail.

Engineering students behind the Adelaide University prank to hang a car from the footbridge. Picture: Adelaide University's Lumen magazine.

Hamish Robson, 77, was the chosen driver of the car. He admits to a few “heart palpitations” as the vehicle with no motor, gearbox or brakes, was pushed several hundred metres from near the zoo to under the bridge on the university side.

A self-confessed serial prankster of the time, Hamish chuckles as he admits while a select few definitely knew of his involvement over the years, many others “did seem to see me as a prime suspect”.

University students hanging an FJ Holden motor car from Adelaide University footbridge, as part of PROSH week stunt. Picture: A student publication from 1971.

University magazine editor Mark Douglas says an identical of the light blue FJ Holden was sourced for the reunion where much discussion revolved around the engineering feat.

The men chatted about how the car’s centre of gravity was determined and holes punctured in its roof to pass a chain through to a piece of wood under the floor that was designed to keep it hanging level.

There were recollections of hooks being welded onto the car and a crane being used but Mark says no one was able to remember exactly who bravely climbed under the bridge to fix the chain to the vehicle.

It also turns out the Holden was in fact the second car to land in the River Torrens after a similar prank failed the year before.

Hamish, who went onto work as an engineer overseas and then spent decades teaching at SA high schools, evades questions about whether his own students have committed similar pranks.

He is more open about telling how authorities and the public were not overly concerned about the dangerous car-hanging feat.

“The world has become a lot more sensitive,” Hamish says.

“I sometimes look back on those times and think ‘my goodness, did we really do that?’”

The gang: Alan Palmer, Dean Eckert, Hamish Robson, Ross Patterson, Wayne Groom, Geoff Wallbridge, Andy Parsons, Lou Baggio, Peter Wilson, Brian Saunders, David Fitzsimmons and Andy Dunstone.

Originally published as Identities revealed: Who executed SA’s notorious River Torrens bridge prank?