The federal government's insurance fund has footed a bill nearing $30,000 to repair three chauffeur cars impaled by bollards deployed in error at Parliament House.
Problems seem to have emerged since authorities turned off the automated system, leaving it to drivers to manually operate the security measure.
Comcover, the self-managed insurance covering government agencies, shelled out for the repairs after the Finance Department paid $500 in excess for each of the three Comcar vehicles damaged by the retractable electronic bollards.
In three separate incidents during November, the bollards were deployed manually in what the Department of Parliamentary Services called "human error", hitting cars from underneath as they were mid-transport and causing $28,935 in damage.
The problems began with a $126 million program of works to fortify Parliament House against terrorist attack, which contributed to the havoc by interfering with the automatic operation of the bollards and requiring them to be run manually.
Three luxury cars hit in November were victims of human operators deploying the bollards at the wrong time.
The Comcars came off second best in each episode, the Department of Parliamentary Services said, leaving the bollards unharmed.
Another two incidents in early 2018 brought the casualty list of Commonwealth cars to five, although no figures have been made available so far on the damage bill there. Cars have suffered everything from smashed transmission systems to pierced undercarriages.
Made of heavy steel and driven by powerful pneumatic motors, the bollards can spring out of the roadway with such force they can fling large trucks into the air.
No parliamentarians were aboard any of the vehicles caught, and there were also no reports of injuries, according to the Department of Parliamentary Services.
Comcover pays damage and losses for 160 government agencies with a reserve accumulated from the premiums it collects from them.
Victorian independent senator Derryn Hinch responded last year by blasting the security works, saying they had triggered the offending bollards.
"That bloody fence," he wrote on Twitter. "More $$$ needed. Parliament House security fence work has interfered with electronic bollard triggers.
"Three Comcars damaged so far by misfires. One gear box wrecked."
Comcars provide chauffeured transport for the Prime Minister, the Governor-General, members of parliament, judges and guests of government.
Entrances for parliamentarians have been surrounded by construction zones as part of fortification works, with new steel security fencing being built on all four sides and technology upgraded across the precinct.
The massive security upgrade at Parliament House, including fences blocking access to the building's iconic grassed roof, was rushed through Parliament after terror attacks against the Canadian Parliament.
The bollards, installed in 2005 as part of an $11.5 million "security enhancement" of Parliament House, were to operate automatically, though the system could be overriden manually.