There have been 50  "slips, trips or falls" into the gaps between trains and platforms on Melbourne's rail network in the 12 months to June 2015.

Figures from the Office of the National Safety Regulator indicate there was an accident, minor or major, almost every week in the past financial year, yet there are no uniform standards for the size of the gap between trains and platforms on Melbourne's rail network.

A spokesman for Transport Minister Jacinta Allan said the state government was working to "progressively" fix the problem. It's not yet known which stations will be improved first.

An accident of history – in which many platforms were built decades ago while rolling stock has been modernised and reconfigured – has left a legacy of dangerous gaps at some older stations. The so-called "stepping distance" can be widest at stations with curved platforms.

The distances between trains and platforms at a number of old stations can be up to 30 centimetres – three times wider than the the 10 centimetre maximum "horizontal offset" at new or upgraded stations.

The standards applied to the gap at any particular platform were "the standards which were current at the time of construction of the platform or at the time of any upgrade of the station," according to a Metro spokeswoman.

An independent investigation by the University of Melbourne's  Centre For Advancing Journalism identified several stations with wide gaps:

• West Richmond station, platform two (curved) – 30 centimetres;
• Auburn station, platform three (curved) – 25 centimetres;
• Camberwell station, platform three (slight curve) – 23 centimetres. 

Australian Disability Standards for public transport mandate a gap no wider than  four centimetres, and no higher than 1.5 centimetres. Public Transport Victoria's design standard for gaps at new stations is no wider than 10 centimetres, though some variation is allowed.

Concerns about the gap between trains and platform at Toorak's Heyington Station were raised with Metro Trains  just three months before an 18-year-old man slipped to his death on that platform early last year.

Hughesdale commuter Gary Dellora contacted Metro after becoming concerned at the extent of the gap at Heyington, which he believed posed a serious hazard to passengers.

"You sort of get used to normal gaps, but this one looked outrageous," Mr Dellora said.

Soon after his alert, in February last year, Glen Iris teenager Mitchell Callaghan died after falling between a train and the platform at Heyington while on a night out with friends.

Mr Dellora recalled: "It just gobsmacked me that the very [railway platform] I complained about was the one the tragic incident occurred at."

Late last year, rubber edging was added along the length of the platform at Heyington and the track was realigned after Mitchell's family and friends petitioned to have the station made safe.

In the emailed response to Mr Dellora before the accident, a Metro customs relations manager said the rail operator was working closely with Public Transport Victoria to measure clearance distances at platforms  to prioritise works to fix "substandard platforms".

Mr Dellora said that he had approached Metro again on learning of Mitchell Callaghan's death, asking if anything had been done following his warning, but described Metro's response as disappointing. He accused the operator of "passing the buck" to the state government.

He added: "A man-trap's a man-trap … It shouldn't take someone's death to address these issues".

Metro's spokesman declined to comment on the 2013 email "on account of current court proceedings".

Posters, "mind the gap" stencils and announcements have been used on Melbourne's rail network for many years, according to a spokesman for Public Transport Victoria. While every train driver has a ramp disabled passengers can use to board, raised access ramps are "being rolled out across the network," a spokesman said.

A version of this story appeared on The Citizen website.