Jaws' legend's son Ian Shaw brings the real story of the blockbuster film to Edinburgh Fringe

Ian Shaw as his dad actor Robert Shaw in The Shark Is Broken

Some 44 years after it terrified a generation, the true story of the filming of Jaws, Steven Spielberg's ground-breaking 1975 movie about a man-eating shark, will be brought to life at the Fringe, this August.

However, while Jaws remains one of the most thrilling blockbusters ever made, for the cast, filming the Oscar winning movie was a constant struggle, as recalled in the play The Shark Is Broken, written by Ian Shaw and Joseph Nixon, which will receive its World Premiere at this year's Festival.

Set in Martha's Vineyard in 1974, the piece finds three iconic actors, Robert Shaw, Roy Scheider and Richard Dreyfuss, tortuously confined together on the Orca while filming.The three must endure endless delays, studio politics, foul weather and a constantly broken mechanical shark called Bruce. In this claustrophobic atmosphere conversation soon deteriorates into actor insecurities, competing egos, petty rivalry and excessive alcohol consumption.

A young Ian Shaw inspects Bruce the Shark

Inspired by the diaries Robert Shaw kept during the filming of Jaws, the piece is a hilarious snapshot behind the scenes of Spielberg’s career defining movie, offering startling insights into one of the greatest Hollywood blockbusters of all time.

Co-writer Ian Shaw, son of Robert, also plays his father in the play, which will run at Assembly George Square. Today, the 49-year-old bears an uncanny resemblance to his dad, but at the time of filming he was just a child of five.

He says, "I have always been a huge fan of Jaws. I'd be a fan if my dad wasn't in it. It's a beautiful piece of film making, so many talented people gathered together in one place to create a perfect storm."

He continues, "The play was partly inspired by his diary, but contains little content from it. The conflicting relationships were documented in the wonderful Jaws Log by Carl Gottlieb, numerous documentaries on TV, and the press interviews."

A young Ian Shaw with dad Robert and actress mum Mary Ure

Tensions between Shaw and Dreyfuss have been widely acknowledged, the stress of shooting at sea leading to many delays - Spielberg famously calculated that during a 12-hour day an average of four hours were spent filming, with actors and crew frequently seasick.

Today, Jaws is considered one of the greatest movies ever made and widely credited with having invented the summer blockbuster - it became the highest-grossing film of all time until the release of Star Wars in 1977.

For Ian, however, an added responsibility comes with the play, that of portraying his own father, a task he describes as, "Emotional. Significant. Interesting. Dangerous."

It no doubt brings back memories of the hours he spent as a child on sets around the world with his dad.

"My memories of sets is that they are quite boring places," he concedes. "I remember huge cables snaking all over the floor. Pyramids of Fresca cans. It feels like nothing is is going on and then all of a sudden, something happens. I went to Shepperton Studios while they were filming Force Ten From Navarone and out of the blue there was a large explosion and dust settling everywhere.

"They were filming the blowing up of a dam. Then it was back to glacial tedium. Film-making is so slow, it's as exciting as a traffic jam most of the time. And just very occasionally, the calls of 'Quiet please! Quiet on set! We’re filming! Rolling! Sound? Speed! And ACTION!'"

He adds, "It was the travelling I remember; Spain, Mexico, America, the Caribbean... and the wonderful food."

Assembly George Square, Studio 3, 2-25 August, 11am, £10-£15, 0131-623 3030, www.assemblyfestival.com