Colin Wiggins, 40, was given the task of supervising teenager Alec Meikle when the 17-year-old began work as an apprentice at the Bathurst plant of train manufacturer Downer EDI in January 2008.

An inquest into Alec's death at Glebe Coroner's Court has heard the young man was subjected to near-constant verbal abuse and put downs abused by Mr Wiggins.

Other staff allegedly burnt Alec  with a welding torch, sprayed him with adhesive spray, set him on fire and suggested that he would be raped with a steel dildo if he made too many mistakes.

In October 2008 Alec hanged himself with rope from a staircase bannister.

Mr Wiggins, who was suspended from supervisory duties for three months after the bullying was reported, yesterday denied ever bullying or abusing Alec, and said he had been “very shocked” when the allegations were first put to him in May 2008.

“I couldn’t see those sort of allegations happening,” he said.

“I’d never seen it before and I’d never heard of it happening.”

Mr Wiggins said that while he and others at the Bathurst plant used “colourful language” including swearing, this was “never directed towards anyone specifically”.

He flatly denied calling Alec a “[expletive] useless [expletive]”, “stupid”, “useless” or “dumb”, as the young man had claimed before his death.

“Verbal abuse? No. I couldn’t see me saying that to a young guy. It’s not me, it isn’t in my nature,” Mr Wiggins said.

The inquest has heard that within days of starting at Downer EDI, staff put up a “sphincter dilation” chart in relation to Alec.

The teenager’s mistakes were allegedly recorded on the chart and it was allegedly suggested that he would be raped with a steel dildo if the top of the chart was reached.

Mr Wiggins denied a role in either creating or filling out the chart.

“The first time I saw the chart was when David Hall, Ben Eagle and young Alec Meikle were standing around it,” he said.

“There didn’t seem to be any malice.

“They all seemed happy, but in hindsight I should have got rid of it. I sort of lacked there ... I should have got rid of it.”

Later, under cross examination, Mr Wiggins agreed that the chart had been designed to pressure Alec into getting his measurements right while undertaking work.

But he believed that, rather than being raped when the top of the chart was reached, the idea was hat Alec would be presented with a steel dildo “as a dildo”.

* Readers seeking support and information about suicide prevention can contact Lifeline on 13 11 14 or Kids Helpline 1800 55 1800.