John Boorman, director

Warner Bros had acquired the rights to James Dickey’s novel, and, after making Hell in the Pacific in very difficult circumstances, they felt I was the man to take it on. I’d never been to the south before, but the first thing I did was go to meet Dickey. We drafted the screenplay together. Always by correspondence, because whenever we met we never got much done. It was the drinking, really. On one occasion, he came to LA to work, but locked himself in a hotel room with a ballerina called Amy Burke.

Warners were never very convinced. Once we had the script, they said: “We’ll do it if you can cast two stars.” I secured Jack Nicholson and Marlon Brando, but they were too expensive. Eventually, the studio said: “Make it with unknowns for $2m.” I had budgeted for a composer and orchestra to flesh out Duelling Banjos as a musical theme, but in the end I just hired a guitar and banjo player to do variations on it in the studios. That was the whole score. I found Ned Beatty and Ronnie Cox from regional theatre, and eventually went to Jon Voight to play Ed, the lead alongside Burt Reynolds. But he couldn’t make up his mind. In our last phone call, I told him: “I’m going to count to 10. And he finally said yes.”

Billy Redden looked extraordinary but couldn't play the banjo so a musician crouched behind him doing the fretwork

We needed someone who looked inbred for the banjo player. My assistant found this boy, Billy Redden, who looked extraordinary, but couldn’t play. So we made a shirt with an extra sleeve in it, and a musician crouched behind doing the fretwork as Redden strummed. There was a lot written afterwards about how Deliverance libelled mountain people. But the locals were thrilled with the film.

We rehearsed for quite a long period, because we had to get the actors up to scratch in archery and canoeing. I had already been down the Chattooga, a ferocious river, to make sure it was safe. But I did the scene where their canoe breaks apart on another river, which was dammed. I got them to close all the sluice gates upstream, so only a trickle came down. That let us build rails on the riverbed, so we could mount the canoe on them, and trigger the breakup later. When we came to shoot, I was down at the bottom of the cataract on the phone to the dam. But I got impatient and got them to open all the gates. We just about survived the avalanche of water.

All the Warners execs walked out without a word at the first screening. They said: “There’s never been a film in the history of Hollywood without women in it that made a lot of money.” But it made $46m, the No 5 film that year. And it’s entered the language, as poor Ned Beatty can testify. Wherever he went, people would say: “Squeal like a pig!” It went on for years.

‘We were all taking risks’ … Jon Voight, left, and Ned Beatty. Photograph: Ronald Grant Archive

Jon Voight, actor

I resisted making the movie up to the very last point. Reading the script, I’d got stuck on the rape scene. But after John pressurised me, I read the whole thing out loud to Marcheline Bertrand, who later became the mother of my children. And I started seeing myself in the piece. One point specifically: when Ed is climbing the cliff to go and shoot the toothless guy, he looks over at the waterfall and says: “Christ, what a view.” I couldn’t see anyone else doing that moment of poetry as well.

The scene where Ned and I are taken up into the woods by the hillbillies is maybe my favourite shot in cinema – it’s done all in one phenomenal take. I pushed John to it, I said: “Do it in one. It’ll be more exciting, because they’ll see it happen right in front of them. No tricks.”

I almost got killed climbing the cliff. I was 10ft up on the face when I started to slip

We were all taking risks, but John was fearless. At one point, one of the actors freaked out and said: “I can’t do this any more.” And John says: “It’s very simple.” He grabbed an oar, jumped into the canoe and goes downstream, around stuff, and over a log. With that done, nobody could deny him.

I almost got killed climbing the cliff; I decided I needed to do it so it could be shot in closeup, which wouldn’t be possible with a stuntman. I was about 10 feet up on the face, which was slippery and almost perpendicular. I told the two grips below me: “If I start to fall off, I’m going to push off the rocks. And you’ll catch me.” I started to slip, called out and one of them caught me. There was a sharp rock inches from my head.

The movie still has significance: the idea of people facing violence and what our responsibility is, how we have to step up. We leave the protection of others to certain members of our society: policeman and the military. But in some way we lose part of our manhood by hiding, by coddling ourselves into thinking we’re safe.