It was April 30, 1970, and Queen Elizabeth II was mingling with excited staff at a white goods factory in NSW's central west.
The monarch had insisted on visiting Orange's Email white goods factory — the town's biggest employer — instead of spending her time taking in the stunning countryside.
"It was a huge boost for the town," local historian Liz Edwards said.
The Queen had no idea that just hours before, what local police believed was an attempted assassination plot, targeting her and husband the Duke of Edinburgh, had failed.
So the story goes, would-be assassins placed a large wooden log over the train tracks at Lithgow, west of the Blue Mountains, in an attempt to derail the locomotive carrying the royals.
The 44-year-old Queen and Prince Philip had been bound for Orange, the next stop on their royal tour.
The advance train ahead of the Royals' locomotive struck the log, but because it was going so slowly it did not derail, and the royal couple were apparently unaware anything untoward had happened at all.
In fact, it took almost 40 years for what's become known as the "Lithgow Plot" to come to light.
Back in 2009, old friends former detective superintendent Cliff McHardy and ex-Lithgow Mercury police reporter Len Ashworth decided it was time the public knew the tale.
Mr Ashworth, now retired, said Mr McHardy and his paper's former editor Bele Lleyton had a "closed meeting" in the Mercury's office days after the incident.
"Apparently the police had requested as a matter of national security that nothing be published."
The former police scribe said Mr McHardy would later fill him in on all the details, but he agreed not to print anything.
He said "it was certainly frustrating", as a seasoned journalist, to be held to secrecy over the years.
And the odd tease from his mate Mr McHardy didn't make it any easier.
"After Cliff left Lithgow he used to keep in touch, and every now and then he'd drop a little line, 'you never did get that royal train story'," Mr Ashworth said.
Thirty-nine years after the fact, when Mr Ashworth was the Mercury's managing editor, the duo agreed to reveal the story they'd held secret for so long — and it went global.
"It was probably my biggest scoop, 30 years after the event."
Not everyone believed the yarn, however, with Mr Ashworth recalling a phone call from someone who claimed to have been on the train that day in 1970.
Apparently, those in the royal security detail weren't even told about the log.
"After I ran it, a few days later I got a very irate call from a former federal police officer in Canberra who had been in the security detail," he said.
"He accused me of fabricating the story. I said to him, 'Well no, I haven't'."
Apart from the police, he claimed a railway man he knew also corroborated the presence of a log on the tracks.
Mr Ashworth says the man told him police brought a log to nearby Bowenfels station and stored it in a signal box.
To this day, he's not sure if it was a deliberate plot against the Queen or just a "random act of vandalism" — but says "the incident certainly happened".
"I believe the police only had one possible suspect, and I don't think it was a particularly strong suspect either," Mr Ashworth says.
"And that was a local person who was known to have had IRA [Irish Republican Army] sympathies.
"It was an incredible story. It was a mystery."
No one was ever charged over the purported attempt on the royals' lives.
Mr McHardy, who passed away in 2017, told the ABC in 2009 that not finding the culprits was one of the biggest regrets of his career.
"You can't say outright that it was an attempt to kill the Queen but it could well have been," he said.
"It [the log] was about six foot to seven foot, about eight inches to nine inches diameter; enough to put a train off rails.
"We were told that if it was going at full speed [the train] it would have had to derailed it."
He believed investigators' hands were tied by the secrecy surrounding the incident.
"It was one of those inquiries where you couldn't ask anybody directly what your inquiry was all about," he said.
Buckingham Palace claimed to have no knowledge of the incident when it came to public attention 13 years ago.
NSW Police, at the time, said it was no longer actively investigating the matter.
