One morning in the mid 1970s Dave Tangye felt a bit like Sherlock Holmes. Right... there’s Ozzy Osbourne asleep on the sofa. He’s still wearing the gamekeeper’s outfit he changed into after we got back from the pub last night.

He’d seen ducks on the pond behind his house and said: ‘I’m going to get them.’ Then he came downstairs in his Elmer Fudd gear, carrying his shotgun.

Ozzy’s hat is covered in frog spawn. Strange. Dave goes outside. Where’s the Range Rover?

Forty years on, an image remains clear. “I can see the roof of the Range Rover glistening in the pond,” recalls Dave. “A local farmer pulled it out. I noticed there was an empty bottle of whisky on the dashboard.”

Just another day at Atrocity Cottage – the nickname given to Ozzy’s home in rural Staffordshire. Dave lived there from 1975 until 1977. He was Ozzy’s personal assistant. The job included such challenging tasks as; ‘making sure he got to gigs. Making sure I kept him reasonably sober’.

It’s to Dave’s credit that he usually managed this, at least when Ozzy was due on stage that night.

Ozzy is still the singer with Black Sabbath; one of the world’s biggest rock bands. At various times he may have had one of the world’s biggest drink and drug habits.

Dave was a much-needed calming influence. It’s easy to see how. His west Cumbrian drawl is the perfect soundtrack to a laid-back manner.

Black Sabbath are back in the headlines. Last Saturday they played what was billed as their last ever show, at Birmingham’s NEC Arena.

Meanwhile an updated version of the 2004 book Dave co-wrote about the band has been issued in digital format. Black Sabbath: The Thrill of it All relives his time with them, and reveals the role this part of the world played in their early years.

The four members of Black Sabbath are from Birmingham. In the late 1960s the two previous incarnations of the band, Mythology and Earth, played regularly in Cumberland and the Borders thanks to local promoter Monica Linton.

They often stayed in Carlisle and played such rock ‘n’ roll hotspots as Low Hesket Village Hall.

Dave grew up in Egremont and saw them at venues including The Tow Bar Inn at Nethertown and Banklands Youth Club in Workington, chatting to Ozzy after shows and getting on well with him. Earth became Black Sabbath in 1969 and the following year had a worldwide hit with Paranoid.

By 1973 Dave was an engineer, and a part-time roadie for Egremont band Necromandus who were touring with Black Sabbath. Ozzy remembered him. When Necromandus split up in 1975, Ozzy offered Dave the job as his assistant.

“We gelled,” says Dave. “I got on really well with Ozzy. I used to look after the security side, make sure he got to places. I used to drive him around. On tour I was just looking after his well-being.

“The band come from Aston, an industrial part of Birmingham.

“They were great people. No airs and graces. You had fun. But you had to do your job.

“If they were touring or in the studio it was quite serious. It was too expensive to not be serious. There was madness on days off.”

Dave accompanied Black Sabbath on several tours of Europe and North America as they played to thousands in arenas and stadiums.

“It was an eye-opener travelling round with them. Especially America. Ozzy got arrested, I think it was in New Jersey. I was in bed with this two-day bug that everybody had had. It wiped me out. I heard all this banging. Ozzy was letting fireworks off in the corridor. I got a phone call: ‘He’s been arrested! They’ve thrown him in the nick!’ ‘Well he can stop there!’”

Back at Atrocity Cottage the carnage continued. Dave recalls pouring cider over Ozzy’s flaming flares after the singer fell asleep by the fire. The wild man of rock kept chickens. “They wouldn’t lay. Ozzy got his shotgun and fired a warning shot. It worked! He found out there were rats under the dog kennel. So he set fire to it. When the dogs weren’t in there, thankfully.”

Dave also saw the softer side of Ozzy when the singer reverted to being John Michael Osbourne with his wife Thelma and their three children.

Ozzy sometimes accompanied Dave on visits to Cumbria. “He used to stop at my mam’s in Egremont. He used to love Cockermouth and Egremont. I remember taking him to an auction at Cockermouth. He was bidding on the cows. All these farmers were looking at him with his long hair.

“He used to go in the pubs like The Cock and Bull in Cockermouth, The Globe in Egremont. He was like the Pied Piper. He always had a crowd around him.

“He was just a natural guy. Ozzy used comedy to get on with people all his life. He’d had a hard life. Him and three sisters and two brothers and their mam and dad had all lived in a two up, two down. It was one of them ‘first up, best dressed’ things.”

Dave remembers the morning after one night on the town in Egremont. “We’d been out for a couple of beers and come back to the house. Next morning Ozzy said; ‘I need to go to the doctor’s. I’ve been having terrible hallucinations – I can hear sheep!’

“I said ‘That’s Jack Southam. He’s got sheep in his back garden.’”

In the late 1970s Ozzy temporarily left Black Sabbath, and Dave left Ozzy. “Things got a bit funny,” he says. “I don’t think Ozzy could afford to pay me.”

Dave worked with him again for two years in the early 1980s, accompanying Ozzy on his first solo British and North American tours.

“I came home halfway through the American tour,” says Dave. “I didn’t like it. I was in an awkward position. He and Sharon were hitting it off. I was getting phone calls from his wife saying; ‘where’s he at?’

“After I got home, Randy Rhoads, Ozzy’s guitarist, got killed in a plane accident. I used to knock around with Randy. I wonder if that was fate? I could have been on that plane.”

Black Sabbath enjoyed continued success with Ozzy back in the band. Ozzy – bumbling, loveable Ozzy – became a star far beyond the world of heavy metal music thanks to reality TV show The Osbournes. And Dave stepped back into normal life.

“It was quite strange. Some days I missed it terribly. But needs must. I just went back into engineering. I travelled quite a lot with that, the Middle East. It was more or less the same set up, just a different set of lads.

“You meet some great lads when you’re working away. You kind of look out for each other. It’s similar to a band. The camaraderie.”

Dave returned to Cumbria and worked at Sellafield for 11 years before recently retiring. Now 66, he is currently single and lives at Brigham, near Cockermouth. He is used to people being surprised by his former life.

“I don’t look like a heavy metal guy,” he smiles. “But it was a while ago. In 1975 I was 25.”

He last saw Ozzy about 20 years ago. They sat backstage after a gig, remembering the old days. They have spoken on the phone since.

Dave wrote The Thrill of it All with Black Sabbath roadie Graham Wright, who was on the band’s last tour. Ozzy and Sharon often asked Graham how Dave is.

Next year will be the 50th anniversary of Ozzy joining Earth.

Although Black Sabbath have supposedly just retired from touring, Dave would not be surprised to see them play again to mark this milestone.

“It’s just in the blood,” he says. Theirs, and his.

Visit www.blacksabbath.co.uk for details of how to buy Black Sabbath: The Thrill of it All.