While the report lauded the bravery and resilience of the injured workers and longwall deputy Adam Maggs, it also found that the mine’s levels of production exceeded its ability to drain dangerous gases and that the issue was known.

It said workers were repeatedly subjected to an unacceptable level of risk and the equipment needed to drain the extra gas did not arrive until a month after the explosion.

In the lead up to the explosion in May, there had been a series of “high potential incidents’’ at the central Queensland coal mine and the board found that the mine should have reduced its level of production, once it understood the “gas make’’ to be significantly greater than had been predicted.

“This is especially so after April 3, 2020, when the investigation in relation to the first seven HPIs was concluded,’’ the report said.

“Daily average gas make at LW 104 was at least 65 per cent greater than on LW 103. As a consequence, Grosvenor was caught short, not having sufficient post-drainage capacity for its targeted rate of production.’’

It also found the Government inspectorate did not have complete information about the conditions under which mining operations were being conducted during work on longwall 104.

“However, even allowing for that, the Inspectorate did not give LW 104 the attention it warranted,’’ it said.

It said an acceptance by the inspectorate that Grosvenor had adequately dealt with previous issues was “inappropriate’’.

It found the workers were hit by two pressure waves. One of the injured workers, Wayne Sellars, described it as being like “standing in a cyclone’’.

The board report said Anglo chief executive Tyler Mitchelson gave further evidence that his expectation was that senior management would reduce production rates where necessary, so as not to exceed the capacity of its gas drainage system.

“Contrary to Mr Mitchelson’s declared expectation, this did not occur,’’ the report said.

It said there was a perception among coal mine workers that a labour hire worker or contractor who raised safety concerns at a mine might jeopardise their ongoing employment at the mine.

While there was no evidence to back that perception “the existence of a perception, no matter how widespread, creates a risk that safety concerns will not always be raised’’.

Mitchelson said the company was acting on the recommendations of the board of inquiry’s report including $60 million of investment in safety initiatives over the past year.

“We are today committing a further $5 million to fund underground mining research, in partnership with our industry research and technology partners, to improve the industry’s knowledge in certain technical areas,” Mitchelson said.

“We have been clear from the outset that the incident on 6 May 2020 in which five of our colleagues were badly injured was unacceptable. The safety of our workforce is always our first priority.

“Over the past 12 months, we have put in place a range of measures to address issues that have come to light through detailed investigations and evidence before the Board of Inquiry. ”

CFMEU district president Steven  Smyth said the most shocking thing to come out of the report was the detailed account of Anglo’s failure to manage dangerous gases at Grosvenor in the months leading up to the blast.

“Management knew there were problems following a series of high potential incidents during March and April, but did not slow coal production to match its gas drainage capacity,” Smythe said.

“Last year’s explosion was a shocking and traumatic event and it makes my blood run cold to think that the outcome could have been much worse.

“Coal mine workers put their lives in the hands of mine managers every time they go to work and they should be able to have confidence every possible measure is in place to protect them. They have been seriously let down in this case.”