Pictures: Officers keep Shropshire streets secure for revellers

"If we lock nobody up, and there's no trouble, that's a success," he tells them.

With around half a century's service between them, there is little in life that surprises Mr Klair and his colleague, Inspector Chris Haslam.

Tonight they are leading Operation Stour, a campaign to reassure the public following a number of incidents in and around Telford's nightspots over the past few months. At the forefront of Mr Klair's mind is an alleged rape just outside Oakengates last month, and officers have been going out in force on Friday and Saturday nights since, talking to the public and ensuring everybody gets home safely.

Chief Inspector Rik Klair, a policeman for 25 years, believes young people are far better behaved today then they were a generation ago.

And he reminds officers that their role is about public safety, and that they should use discretion when dealing with minor misdemeanours. "People are out to have a good time," he says. "I don't want people being locked up for minor things. We're just looking for people who might be vulnerable."

Mr Klair says most young people are polite and well-behaved. Most of the interaction he and his officers have is good-humoured. "It's got better by far – when I joined, there was far more violence," he says.

"There used to be far more damage to property at night during the weekends. I think that change is significantly down to the culture where people drink more responsibly, and more do so at home than they used to."

He says football-related violence used to be a problem on Saturday nights, but that threat has reduced dramatically.

Mr Klair, who has lived in Shropshire all his life, says that closed-circuit television has also played a major role in making town centres safer at night. "We hardly get a window broken now because people know they might be caught on camera," he says.

Perhaps surprisingly, his colleague Inspector Haslam believes the liberalisation of drinking laws, which allow pubs to open into the early hours, has had a positive effect.

"When the new laws came in some years ago, more freedom was given for pubs to open for longer, and many of the traditional nightclubs closed down as people could stay out later in the pubs. Nowadays, people are less likely to drink a lot of alcohol to get it in just before last orders. People can pick their drinks over a long period of time, so there is more of a steady trickle until the last clubs close at five or six in the morning."

Mr Haslam says: "I believe the CCTV system we have plays a very important role. We have people in the control room looking at live feed coming in, and if there's anything that looks like potential for disorder – people arguing and pushing in the taxi queue, for example – we will go there.

Just before midnight, a young, stockily-built man appears to be testing the officers, asking if it is all right for him to punch somebody if it is in self-defence.

At five-to-one in the morning, the first real action begins when Pcs Ben Walters and Ross O'Neil give chase to two men acting suspiciously in an alleyway.

They find two men standing on the corner of Market Street and Uxacona Way in Oakengates, but it quickly becomes apparent that they were not the ones they are looking for, with the one barely able to stand up. It transpires that the second man had merely come to his aid, having spotted the first man being sick. The constables offer to call the drunken man a taxi, but he begins to amble off.

"We can't run their lives," says Pc O'Neil, who spent seven years as a PCSO before retraining last year. "He's not under arrest and he's been sick, which should make him feel better. We would prefer him to go home safely in a taxi, but it's his choice."

Ten minutes later, there is more action as Mr Haslam and his fellow officers run after a group through Market Street, quickly detaining a man in an alleyway.

"An argument broke out between one of the girls and her boyfriend; she said she didn't want her boyfriend talking to the man we stopped because he sells drugs," says the inspector. The suspected drug dealer, clearly under the influence of alcohol, initially protests as the officer explains stop-and-search procedure. During the conversation, he reveals that he is on bail for another matter and complains that the police often spell his name incorrectly.

"Don't get me wrong," he tells the small crowd in the alley, "I take drugs, but I don't sell drugs." Despite his admission, he is found to be clean.

At 1.20am two officers walk past the kebab shop in Market Street when a man gives them a slow hand-clap, singing the tune to The Adams Family. "You ought to be on X Factor," one of them replies. A thick skin and a sense of humour are pre-requisites for the job, the officers say.

"You attract people who want to talk," says Mr Haslam, who served 16 years in his native Manchester before moving to Shropshire eight years ago. "Some of it is friendliness, some of it is taking the mickey, but we just go along with it."

Pc O'Neil, who is 28, adds: "Everybody wants to tell you their story, either about how they have had a bad experience with the police in the past, or they will ask if you know Pc so-and-so."

At 1.45am Mr Haslam does a "walk-through" at Industry nightclub in Lion Street, chatting to bouncers before walking across the dance floor and inspecting the toilets. The inspector, who only this month took up his post with the Donnington Safer Neighbourhood Team, says:

"I have never been to the club before so I wanted to familiarise myself with the layout, to see if there were any obvious signs of drugs, under-age drinking, and to check out the demeanour of the staff.

"Everything seems to be in order."

At 2.40am Pc O'Neil enquires about the welfare of a tearful girl wandering the street. "Her and her boyfriend have been like that all night, they keep arguing and then making up," says Pc O'Neil. They go into a kebab shop where the boyfriend appears to be play-fighting, when a call goes out at 2.50am for reinforcements to be sent to reports of disorder in Newport.

At 3.25 a man approaches Pc Walters saying he has left his hoodie in the Duke Box bar. To the officer's surprise, the bar is opened up so the man can get his jacket.

At 3.35 it is time for Pcs O'Neil and Walters to do a final lap of the town. "At this time it is usually just the stragglers," says Pc Walters, 39, a former lawyer. The last two revellers appear to be two sharply dressed young men.

"I'm a 19-year-old millionaire," one of the two men announces to the officers.

"You're a millionaire?" they reply.

"Well, a millionaire in the making," he asserts, optimistically.

Industry is open to 6am, but for now the streets are empty. Mr Klair has his wish: the night has passed peacefully and a good time has been had by most, if not all.