Rail, Tram and Bus Union spokesman Phil Altieri said it was not a case of bad luck but rather the poor design of the "cheap as chips" Citadis C-class model, which he said had also been responsible for more than 25 Workcover claims since they were introduced in the early 2000s. Mr Altieri, the union's tram and bus assistant national secretary, repeated calls for the model to be taken off the roads. Emergency workers at the scene after the same tram smashed into a house in Kew in 2016 Credit:Courtesy Twitter, ABC News Melbourne "We've called for that on a number of occasions, not just because of serious incidents, but because they've injured our drivers in the past," he said. "Those trams should all be off the road, but that one in particular.

"[Yarra Trams'] policy is zero harm and safety comes first, but they don't practise it." Mr Altieri said the model's principal design flaw was that the bogies, the rotating housing for the trams' wheels, were not positioned close enough to the front. He said this meant the model was unstable and prone to derailment in a collision, while the vibration and shaking caused slow-burn neck and shoulder injuries to the drivers. A 2012 WorkSafe investigation found the trams were so poorly designed they posed an unacceptable risk to public safety.

Yarra Trams commissioned an independent assessment from ergonomist and engineer Mark Dohrmann the same year. The report found severe lateral swaying of the driver's seat, which was likely to have contributed to workplace injuries. Loading Replay Replay video Play video Play video It also found that the trams snaked at the rear, potentially putting passengers at risk. ''At virtually all speeds above 25 km/h, the rear section of the tram snaked continuously, the problem worsening on the in-bound route along the Port Melbourne line,'' Mr Dohrmann wrote in his report.

Loading ''We consider the problem serious, both from a health and an operational point of view … "It seems that the only way of avoiding the sway at present is to drive at very low speeds, which would be intolerable from an operational and timetabling perspective.'' After the 2012 WorkSafe report, Yarra Trams introduced new servicing to ensure the wheels work with the tracks. Drivers have not filed WorkCover cases for shoulder and neck injuries since January 2016, and there have been no complaints of swaying since October 2016.

Witnesses to Sunday's incident, shortly after 11.30am on Cotham Road, said the tram derailed when the driver of a car failed in an attempt to squeeze in between the front end and another vehicle. The collision caused the tram to jump its track and crash through a fence, coming to rest in the front garden of a block of units. The derailment caused passengers, including a baby, to fall on top of each other. Paramedics assessed two occupants of the car and 19 shocked passengers. One elderly lady was taken to hospital with serious head injuries.

A Yarra Trams spokeswoman said the tram underwent assessments after both previous incidents and would again. She said this would include a review of the tram's history and maintenance records. Yarra Trams said safety was its biggest priority, and all trams meet safety protocol. They are serviced every five weeks. Cars crashed into trams about 1000 times last year. C-Class trams have derailed three times since 2016 after being hit by cars, no more than B and D-Class trams, according to Yarra Trams data.

Asked by reporters on Monday if the fleet was more prone to derailments, Transport Infrastructure Minister Jacinta Allan said she did "not have that advice". "I think it's important to remember the cause of (Sunday's) incident was a car colliding with a tram," she said.