#What it was like growing up in Action Park, the world’s most dangerous theme park

The enclosed water slide, which ended with a disorienting vertical loop, was — as Gene’s son Andy, 58, told The Post — “a ride to survive, not a ride for fun.”

That often seemed to be the case at Gene’s Action Park — a water park in Vernon, NJ, nicknamed “Traction Park” because of countless injuries incurred there.

Now, Andy tells his family’s wild story in “Action Park: Fast Times, Wild Rides and the Untold Story of Americas Most Dangerous Amusement Park” (Penguin Books), out Tuesday. The book offers an unvarnished history of the park, which was open from 1978 to 1996, as well as a portrait of his eccentric father — and an ode to a seatbelts-optional era.

“I grew up in an amusement park. There was a lot of funny stuff that happened,” said Andy.

He owns the claim to fame of ­being the first-ever human to try out the Cannonball Loop — after a homemade test dummy was decapitated. Andy emerged unscathed, thanks to the hockey equipment he wore. Park employees who followed him lost teeth and blood, but earned $100 from Gene, who was known to slip workers cash for giving the ­unproven ride a whirl.

“Like a pharmaceutical drug with serious side effects, the Loop’s human trials had not been encouraging,” Andy writes.

Gene spent years trying to get the slide safe enough for visitors. Workers tried shortening the loop and Gene even had a priest bless the ride. It finally opened in 1985 — only for state authorities to shut it down a month later.

Mulvihill had built Action Park as part of a ski resort he owned, hoping to make a buck in the offseason. The entrepreneur, who’d had a successful stint on Wall Street, didn’t simply want rides — he wanted adrenaline-pumping “sporting attractions” where park-goers could control and heighten the risk, at their own peril.

There was a skydiving simulator called the Aerodium, Battle Action Tanks where riders shot tennis balls at each other, and a Tarzan swing — with crowds jeering as people leapt into cold water

“There was all of this bravado at Action Park. It wasn’t just going on the ride, it was about showing off, competing,” said Andy.

All this, and beer was served, too. Not surprisingly, scrapes, bumps and bruises were frequent.

Some of the wackiest rides at New Jersey’s old Action Park

CANNONBALL LOOP: This ride — a water slide with a vertical loop, complete with an escape hatch for stuck riders — was open for only a month before the state shut it down.

Action Park

ROLLIN’ ON THE RIVER RIDE: According to Andy Mulvihill’s new book, human clogs were not uncommon on the plunging raft adventure that employees referred to as “The Toilet Bowl.”

Action Park

ALPINE SLIDE:  Skin-burning wipeouts were not uncommon on this downhill ride. Tragically, one park employee died when the sled jumped the track.

Action Park

BAILEY BALL: Meant to tumble 360 degrees down a mountain track, this ride never opened to the public after it fell apart while an employee was inside.

Action Park

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Many were attributed to the ­Alpine Slide: Rudimentary sleds, controlled by joysticks, descended a 2,700-foot concrete track, often at warp speed.

“I had my fair share of wipeouts — you would get a bad burn,” Andy recalled. “The surface of the track scraped off your flesh.” On busy days, he added, the park could look like a leper colony.

And then there was the Bailey Ball: a giant plastic globe, covered in caster wheels, that tumbled downhill — with a human inside. It was built by Ken Bailey, who Andy said was a custodian at the park.

Mulvihill paid an employee named Frank $100 to test it. But the summer heat melted the glue that held together the PVC-pipe interior skeleton, sending the ball — and Frank — hurdling off the track and down the mountain, while a state inspector looked on in horror.

“The man in the ball was probably the most treacherous thing that ever happened. It rolled across a street!” says Andy. “We can laugh at it now because Frank only sprained his arm.” The Bailey Ball ultimately rolled into some woods, where it remained for some time.

Tragically, there were six deaths at the park, including drownings and an accident in which an employee hit his head after his Alpine Slide sled jumped the track.

The business started to unravel after Gene pleaded guilty to insurance fraud. Faced with mounting lawsuits and debt, he closed the park in 1996. Years later, Mountain Creek Waterpark — a much more family-friendly place — was opened on the Action Park grounds.

Gene passed away in 2012, but his renegade spirit lives on — especially with the announcement last week that Hulu is developing a comedy series based on Andy’s book, co-written by Jake Rossen.

As Andy said: “[Action Park] was Gene’s approach to life: individualism and the ability to express yourself and have fun.”