The family of Michael Welsh, who died in a mudslide at the mine in 2014, told the coroner’s court they remained broken and scarred by depression and mental illness.

His widow Sandra was 14 when they met.

She said it was hardest to explain to his grandchildren why he wasn’t around.

“He was so attached to his four-week-old granddaughter; he was like a smitten pup,” Ms Welsh said.

“This was an accident that never should have happened and I really hope that justice is served.”

His eldest daughter Tameka said she wanted to see charges laid over his death.

“I really hope the people that stuffed up that day hurt as much as we do,” she said.

“They only have to look at us.”

An engineer has told an inquest into three mining deaths at the Mount Lyell copper mine that a platform two men fell from had a high-level risk of failure.

Craig Gleeson, 45, and Alistair Lucas, 25, fell through the platform while they were working on a piece of mining equipment on December 9, 2013, plummeting 22 metres down a shaft to their deaths.

Engineer Adam Richards told the inquest on Thursday morning that the wooden platform they were working from could theoretically hold a weight of no more than 100 kilograms.

He said the combined weight of the workers and equipment they were using at the time of the incident was 240 kilograms.

The platform was made from King Billy pine which Mr Richards said was not a structural timber and an engineer would not use it to hold weight.

He said the stress grading of timber was weak and the timber would have been overstressed by 260 per cent.

“Even if we were out by 100 per cent, there would have been a problem,” Mr Richards said.

He said the platform did not comply with Australian standards and an engineered timber would have been more appropriate to use as the defects from natural timbers were removed.

“There is nothing wrong with using timber provided it is the right timber,” Mr Richards said.

WorkSafe Tasmania principal mines inspector, Andrew Tunstall, was on-site the day after the incident.

He issues a prohibition notice which prevented any work on the linkage arm which the men were working on at the time of the fall.

This was removed once the mine had a new platform built by an engineer constructed at a $1787 cost.

Mr Tunstall was mine manager at Mount Lyell for three years prior to his current role.

He said he had received no complaints about the temporary platform’s safety during this time.

“I wasn’t aware the temporary platform was being used until the investigation,” Mr Tunstall said.

He said he had visited the mine more than 50 times as an inspector but could not recall a visit to the loading station where the fall occurred.

Fellow mine worker Mark Hull, who had worked for Copper Mines Tasmania for 30 years, said King Billy pine was always used because it was lightweight and he never had concerns it could break.

He said it was easier to perform the task Mr Lucas and Mr Gleeson were doing at the time without being anchored while harnessed.

Mr Hull said the wearing of harnesses was not enforced by supervisors or management.