Berlin's infamous Brandenburg Airport finally gets an opening date

According to Deutsche Welle (DW), the German broadcaster, 90 kilometres of cables were incorrectly installed, 4000 doors were incorrectly numbered, the escalators were too short and the emergency line to the fire department was faulty. It has also been reported that the airport's roof was twice the authorised weight.

A shortage of check-in desks was also identified. The solution offered by planners? To check in passengers using non-German carriers inside temporary tents in front of the terminal. It did not go down well.

Some truly comical problems have made headlines:

Last year it emerged that 750 monitors showing flight information needed to be replaced (at a cost of €500,000) because they had been left on for six years and burned out.

For months in 2013 planners couldn't switch the lights off in the terminal building because of a computer glitch.

Each day an empty train visits the airport's station to keep the tunnels ventilated and stop the track rusting.

A report suggested the airport was considering hiring nightclub bouncers to sound fire alarms manually because the system couldn't be fixed.

Hundreds of planted trees had to be chopped down because they were the wrong variety.

Three thousand smoke detectors reportedly went missing. Flight paths and sound protection zones were incorrectly calculated.

That's not all. There have been allegations of corruption – DW claims the airport's planner-in-chief was "not an engineer but an imposter" – and worrying claims that a whistleblower at the airport was poisoned. This has not been proven.

DW also points to "a botched privatisation attempt, the need to soundproof surrounding homes, and compensation lawsuits" as well as "a simple lack of accountability". "Politicians with limited project management experience were running the supervisory board and could freely make decisions with the knowledge that by the time any complications came to light they – the decision-makers – would be gone," it argues.

According to the German politician Jörg Stroedter, the problems found in 2012 should have led to the decision to gut the building and start again. "If that had happened, the airport would have already been in operation for a long time, with newer and less complicated facilities," he told the BBC.

The problems have been exacerbated in the meantime. Executives and engineers have come and gone, and the collapse of Air Berlin in 2017 created tenancy issues.

Heads have rolled too. The former Berlin mayor, Klaus Wowereit, who famously described his city as "poor but sexy", was forced to resign from his post, in part because of the airport's failings.

The embarrassment for Germany has also been hard to swallow. So much so that the family of Willy Brandt, the German statesman, requested his name be removed from the airport so it wouldn't be associated with such a fiasco.

The saga has also been staggeringly expensive. BER was originally supposed to cost €2.83 billion ($4.59 billion), according to a 2006 report. But by late 2012, €4.3 billion had already been spent. This rose to €5.4 billion by 2014 and €6.9 billion by 2016.

By the time it is ready to open the total bill could reach €10.3 billion, according to some estimates. All of which would leave it around €7.5 billion over budget. The cash has kept coming in thanks to a series of loans, but every month the airport remains unused it sinks further into the red – simply maintaining the empty shell costs millions of euros.

Construction companies, taxi firms and shops have declared bankruptcy due to the ongoing delays, and a scandal broke out last year over how much the airport's head was paying himself.

But BER has become an unlikely attraction

A fine example of schadenfreude if ever we saw one, tourists have been paying to take tours of Germany's disastrous unopened airport. There are various options available, including bike tours, which wend their way around the apron, passing empty terminal buildings and gates.

The bike tours are run by the airport, which, true to form, does not provide bicycles or helmets – visitors must come with their own set of wheels. The airport does, however, provide a packed lunch on the two-hour excursion, which costs €15 per head.

Group tours are also available of the ghostly terminals and check-in areas. Dubbed the "BER Experience", these also last two hours and cost €200 for a group of eight. Those who sign up are currently the closest thing the airport has to passengers.

Hundreds have even taken part in regular "Airport Night Runs" at BER, which include half marathon, 10 km and 4x4 km relay races.

It's not the only unused airport in Berlin that's become a tourist attraction. The abandoned runways and scrubby wastelands of Tempelhof Airport, of Berlin Airlift fame, is now a park – and an unlikely spot for a bit of birdwatching.

The Telegraph, London