In Barrow, Thirsty Thursday wasn’t as billed. Traditionally it’s the night when the thousands of employees working in the town’s cavernous warehouses where the next generation of Britain’s nuclear submarines are being built, hit the pubs.

But last Thursday the Cumbrian coastal town seemed preternaturally quiet. By 6pm there were more seagulls than people in the town centre. A couple of restaurants were doing a lively trade, thanks to special happy-hour offers, but most were empty. Scores of boarded-up shops and “to let” signs suggested Barrow had seen better times.

Geography plays a big part in this story. Clinging to the bottom of a peninsula overlooking the Irish Sea, Barrow, or Barrow-in-Furness to give it its proper name, is a place that few outside the defence, wind power or extractive gas industries are likely to visit. If anyone knows anything about Barrow it’s that it was the birthplace of footballer Emlyn Hughes and in 2014 was judged by the Office for National Statistics to be the most miserable place in Britain.

Unlike Blackpool down the coast, there is no end-of-the-pier feel about Barrow. It’s a working town of terraced houses and tenements built when Barrow’s shipyards were thriving. But with only one road in and one road out, even those who live in the town accept that it can seem an isolated place. “They call it the longest cul-de-sac in Britain,” jokes Kimber-Lee Moore, 27, a bar worker who moved to the town from Carlisle four years ago. They are calling it something else, too, now.

After 12 drug-related deaths since December, Barrow is now Britain’s most infamous “brown town”. A place that was once dubbed England’s Chicago because its economy was growing so fast is now synonymous with heroin.

Cumbria’s heroin problem is not new. Scores of towns on the periphery of the Lake District have had their problems down the years. Penrith, 70 miles inland from Barrow, shed its reputation as a brown town years ago. But the scale of what is happening in Barrow has shocked even those with first-hand experience of the problem.

“There have been drugs deaths elsewhere in the county, but not to the degree we’ve seen in Barrow. It’s totally disproportionate,” said DCI Nick Coughlan of Cumbria police. “The town’s population is only 67,000, so this is a lot.”

To put this in perspective: fewer than two people per 100,000 of the population died from heroin or morphine misuse in England and Wales in 2016, the latest figures available. In Blackpool, the town that has the highest heroin death rate, the figure rises to 14 in 100,000. Barrow, tragically, is in danger of breaking all records before 2018 is even halfway through.

“The deaths in Barrow are not all directly attributable to heroin, but the drugs they are using are ones we associate with heroin users,” Coughlan said. “Often they have taken cocktails of different drugs. Sometimes they involve heroin, sometimes methadone, sometimes other drugs.”

Barrow’s unwelcome place on the growing list of coastal towns hit by the effects of drug addiction (six of the 10 heroin misuse hotspots in England and Wales last year were by the sea) has made it the subject of national attention. In recent weeks newspapers, websites and the BBC have descended on the town to cover the story, much to the dismay of Barrow’s supporters.

“It’s stereotyping every hardworking person in the town,” said Craig O’Callaghan, a contractor from Middlesbrough who spends weeks at a time in Barrow when he’s working on the gas rigs.

Facebook Twitter Pinterest Resident Craig O’Callaghan: “It’s stereotyping every hardworking person in the town.” Photograph: Andy Hall/The Observer

“It has pockets of problems, but it’s not the Bronx,” Moore agreed.

But Coughlan, who was once a sergeant in Barrow and calls its residents “salt of the earth people”, said the police had intelligence suggesting there has been an increase in the amount of drugs entering the town in recent months. Whether this reflects wider national trends is hard to say. Evidence is conflicting.

The number of heroin seizures has been decreasing in the past three years. But purity levels have shot up to near 50%, a vast recovery from the “heroin drought” of 2011 when levels dropped to as low as 18%, something that suggests the drug is becoming more available.

What has changed, without doubt, is the nature of the supply network. Whereas it was once gangs from Liverpool and Manchester bringing the drugs in, criminal enterprises from as far away as Scotland, Birmingham and London are now coercing teenagers to move the drugs, sometimes forcing them to swallow the wraps of heroin to avoid detection.

“People are travelling from much further afield, and the reason is that there’s a market,” said Coughlan, who spoke to the Observer last Thursday shortly after Cumbria police arrested two members of a drugs gang from Tower Hamlets in London targeting Barrow. “When people are prepared to travel a 600-mile round trip, you can see there is a thriving market here.”

According to Coughlan, the battle to carve out a share of the Barrow heroin market has been mirrored with an increase in violence as gangs use baseball bats and knives to establish their territory. Beatings of addicts who cannot pay their drug debts are also on the rise. So, too, is the practice of “cuckooing” – when a gang takes over an addict’s house and uses it as a base for dealing.

Neil Woods, a former undercover police officer who infiltrated drugs gangs and wrote a book about the experience, Good Cop Bad War, said the “county lines” phenomenon –when gangs operate far outside their base – was dramatically changing the shape of the UK drugs market.

“In the past three years it’s become absolutely enormous,” he said. “Large criminal gangs have got monopolies and so people who want to make money are taking over the smaller towns.”

Dr Robert Ralphs, reader in criminology at Manchester Metropolitan University, said technology had transformed the market. “Twenty years ago, when I started research on heroin and drug-dealing gangs or networks, most drug purchases took place around public phone boxes and in open areas such as shopping centres and high streets. Mobile phone technology makes it much easier for deals to take place in closed markets. Setting up a young person in a different city or town is also much easier due to mobile phones.”

Teenagers, often lured into working for the gangs through the offer of free cannabis, also make good drug couriers. Less likely to have a police record, they don’t invite attention.

Woods, who left the force five years ago and is now UK chairman of Law Enforcement Action Partnership, a body that campaigns against the current drug laws, saw the “county lines” phenomenon at first hand when he helped target Birmingham’s notorious Burger Bar Boys gang as it expanded into Northampton.

“It was a huge success: 96 people were arrested and the Burger Bar Boys got something like 10 years apiece. Afterwards I spoke to the drug intelligence officer on the case. He said we’d managed to interrupt the drug flow into Northampton for two hours. The police never change the size of the market – they only change the shape of the market.”

But as police forces struggle with budget cuts, their ability to gather intelligence and infiltrate gangs is diminished. “There’s less of us now than there was a few years ago, so it’s more challenging,” Coughlan said. “We can’t do as much as we did before.”

Perhaps partly for this reason, police and crime commissioners are stressing the need for other agencies to do some of the heavy lifting.

“Of course the number of deaths from drug use in Barrow is extremely worrying – and tragic to see lives wasted needlessly,” said Cumbria’s police and crime commissioner Peter McCall. “It is important that we recognise that enforcement is not the only answer to this problem. We must as a society recognise that we need to address the causes of drug abuse. This is not just a police issue – our partners in the local council and other agencies all have a part to play.”

Facebook Twitter Pinterest The BAE Systems factory that builds Trident submarines, and provides work for many in the town. Photograph: Andy Hall/The Observer

Other commissioners would go much further. Some advocate the use of drug consumption rooms in town centres – something that is supported by health experts alarmed by the country’s rising number of drug deaths: 3,744 people died of drug poisoning in England and Wales in 2016, the highest number since records began in 1993. In the past 25 years there has been an eightfold increase in the number of death certificates in which heroin is cited as a factor in the person’s death.

In Barrow heroin misuse has become associated with one particular district – Barrow Island down by the warehouses where defence giant BAE builds the submarines – and, in particular, Egerton Court, a rundown tenement block, home to four of the 12 people who have died. Here, rubbish litters the stairwells and there’s broken furniture on the pavements.

The communal playground in the court’s centre has been ripped out and some of the windows are boarded up. Conspicuously pinned to a lamppost is a domestic violence protection order issued by Barrow magistrates court banning one Christopher Poore from entering Egerton Court until 16 May – a sign, locals say, of how the police are trying to make the area safer. Kay Turner, 30, a care worker who used to rent a flat in the court and now lives nearby, pays tribute to the spirit of residents. “Best thing about living in Barrow? The community. But you’re always going to get problems. There’s not a lot to do.”

Egerton Court stands out because it is one of three tenement blocks that has not been renovated. Others adjoining it have been given facelifts and attractive modern interiors. Their communal gardens could grace the Chelsea flower show. Turned into serviced apartments, they are rented out to BAE contractors who return to their families at weekends, taking their pay packets with them. Mark Roberts, 47, runs the local newsagent. He was born in Egerton Court but moved out with his parents when he was four as their flat didn’t have a bathroom.

In the early 1990s, Roberts witnessed families moving out to buy houses elsewhere that had monthly mortgages costing less than they were paying in rent. The BAE contract workers who have now moved in, Roberts notes, don’t spend their money in the town. So where do they, then? “Lancaster, Preston, Manchester, Amazon.” And there’s fewer of them now.

When Roberts took over the shop in 1989, BAE employed 16,000 people in Barrow. Over the following years, the company shed 10,000 jobs. Today things have improved, but BAE still only employs less than half the number it did 30 years ago.

When [dealers] are prepared to travel a 600-mile round trip, you can see there's a thriving market DCI Nick Coughlan

Roberts is gloomy about the town’s future. “We need to regenerate, but nobody’s going to put investment in if they don’t know it’s going to work.” Some days he toys with leaving. “I love Barrow, but at the moment my emotional attachment to it is getting less and less.” But then he checks himself. “We’re just half an hour from the Lakes. You can’t beat that.”

If anything good can be said to have come from Barrow’s problems it’s that they have dragged a national public health emergency out of the shadows so that it can no longer be ignored.

“It always catches the eye when we get these particular spikes in particular locations, but it’s part of the overall picture of increasing drug deaths over the years now,” said Ed Morrow, drugs policy lead at the Royal Society for Public Health.

“It really goes to illustrate the issues that we’ve been highlighting for a number of years – that we’re not doing enough in harm reduction, not investing enough in treatment services and not ensuring that those treatment services are geared to the right outcomes.”

For Cumbria, with a budget for promoting public health of just £37 per head, compared with the national average of £57, or £179 for the City of London, finding more money for harm reduction programmes is near impossible. The government’s new drug strategy, introduced last year, may also be helping to compound the problem. A national focus on promoting abstinence and refusing heroin substitutes such as methadone to those who fail to stay clean, is concerning health experts.

Facebook Twitter Pinterest Barrow has the most drug-related deaths in the country; the area surrounding Edgerton Court in the Barrow Island community is the epicentre of the problem. Photograph: Andy Hall/The Observer

Last October Colin Cox, Cumbria’s director of public health, presented a report to the council that warned: “It is possible that taking a strict approach to recovery models, such as ending treatment if clients relapse, might mean that people who are not ready to become drug-free are left without access to support and are put at higher risk as a result.”

Danny Kushlick, of the group Transform, which campaigns for an end to prohibition, is scathing about the strategy and the effects it is having on struggling towns across the country.

“The government has prioritised an ideologically driven abstinence-based recovery agenda over proven harm reduction measures and undermined life-saving and life-enhancing initiatives,” he said. Aware of the criticism, Unity, the organisation that provides drug rehabilitation services in Cumbria, told the Observer that it was now working with a number of partners to help addicts remain in treatment.

Significantly, after expressing alarm about the rising national tide of drug deaths and cuts to treatment budgets, the Royal College of Physicians took the unprecedented decision last week to declare that the problem must now be treated as a health, rather than a criminal justice, issue.

But the shifting zeitgeist is unlikely to offer much succour to Barrow or any other of Britain’s brown towns. Their socio-economic problems are too deep-rooted – the result of a collective failure by successive governments to help prop up Britain’s declining industrial heartlands.

Outside his shop Roberts looked over towards the rubbish-strewn backs of the tenements and shook his head. “The people who live there, they just don’t care,” he said. He repeated the local joke about the town being one long cul-de-sac.

“It’s fantastic if you’ve got something to keep you here. But it’s pretty terrible if you haven’t.”