COMMUTERS at a north Brisbane train station have had a lucky escape after a 10kg chunk of shrapnel punched through both sides of a pedestrian overpass, believed to be thrown from a freight train this morning.

About 8.30am, the Pacific National train experienced what witness Jason Radcliffe described was a major drive-gear failure, sending the 5-10kg chunk of steel shooting up between train freight cars at Narangba station.

Mr Radcliffe’s photos show that the shrapnel shattered the reinforced glass and sheared through the aluminium facades on both sides of the overpass, leaving a hole the size of a basketball.

Fortunately, the cannonball effect of the flying shrapnel did not strike any pedestrians, he said.

“The station master and her assistant should be commended on their quick attention, isolating and making everyone safe,” he said.

Mr Radcliffe is a specialist project engineer who regularly commutes to his workplace from the Narangba station.

He arrived just after the carnage and said the chances of an incident like that occurring was on par with ‘winning the lotto’.

“Ordinarily, if something like this is going to fail, it will bounce up and down under the train,” he said.

“It has swung vertically up from the train, clipped either the train or the carriage, over the top and ricocheted onto the glass and out the other side onto the platform.

“If you look at the logistics of trying to make something do this, you would have more chance of winning the lotto.”

Mr Radcliffe said the station overpass was always busy foot traffic, and the only thing that prevented a tragedy was that it didn’t happen during the peak period.

“If it happened at 7.30am, you would have lost a couple of people,” he said.

A Pacific National spokesman said the matter would be investigated.

“As a leading state rail operator, we pride ourselves on our safety record,” he said.

“We expend significant resources to ensure our equipment is maintained at the highest standard.

“A detailed and thorough investigation into this morning’s incident is already underway.

“We will fully respond to its findings.

“Safety is a paramount concern in all of the communities in which we operate.”

A Queensland Rail spokeswoman said the train experienced an engine failure at Narangba on the Caboolture line.

As a result, the train was temporarily stuck midsection between Narangba and Dakabin stations and Queensland Rail trains were diverted to travel on different tracks, causing delays to City network passenger services.

The incident caused damage to the pedestrian overpass and a small section of the platform at Narangba station.

A ‘rescue train’ was sent to remove the train from the site, which means this afternoon’s peak services will not be impacted.