Piloted by a game controller, fitted with camping shop lights - and a ballast made from old construction pipes: The doomed Titan sub 'red flags' as experts reveal all the key mistakes before tragedy struck

One year ago tomorrow, the doomed Titan submersible embarked on a trip to visit the wreckage of the Titanic.

British billionaire Hamish Harding, OceanGate CEO Stockton Rush, French navy veteran PH Nargeolet and Pakistani businessman Shahzada Dawood and his son Suleman, who was just 19, were all onboard.

Tragically, it was reported as missing and after a desperate race against time before the oxygen ran out, only the debris and 'presumed human remains' were found.

However there is still criticism about the sub's alleged technical inadequacies - as well as the failure to address repeated warnings it was unsafe.

Here we look at the red flags posed by the construction of the sub - and some of the key mistakes that were made in the run up to the tragedy. 

Titan had experienced several safety incidents on previous dives

Inside the OceanGate Titan submarine 

$50 Playstation controller

OceanGate, the company conducting the excursion, revealed that the Titan submersible was navigated by a modified Logitech G F710 Wireless Gamepad first released in 2010.

The controller - which ran on two AA batteries - had a 4.2 out of five overall score on Amazon, but hundreds of one-star reviews dating back more than a decade claim the device suffered from irritating and regular connection problems.

Other themes among the negative reviews included problems with the controller's analog sticks and that pressing certain buttons scrambled the entire pad.

And the Logitech G F710 Wireless Gamepad was only compatible with decade-old Windows and Chrome systems.

The OceanGate Expeditions submersible was steered by a video games controller

CBS correspondent David Pogue is seen inside Titan holding the PlayStation controller

While the world anxiously waited for the crew to be found, the public was shocked about the out-of-date PC gaming controller piloting OceanGate's 22-foot craft.

The silver device featured a traditional gaming system layout with two analog sticks at the front, a black D-pad in the top left corner and colourful buttons to the right.

It featured a 2.4 GHz wireless connection, which users said on Amazon will drop periodically. However, the product overview stated there were 'virtually no delays, dropouts or interference.'

The Logitech G F710 can work wirelessly using two AA batteries or be plugged into a power source.

It is unknown how the controller was powered in the submarine, but AA batteries can last up to 10 years.

The five men inside tiny 22ft tube with no seats and just a single window

The five men were trapped inside the tiny 22ft tube with a single window and no seats, thousands of feet below sea level with no way of reaching the outside world.

Those onboard had to contend with the cramped conditions - all while not being able to see beyond the black depths of the ocean from the single window.

There were no seats and only one toilet - a small black box - with a black curtain drawn across for privacy. All passengers were barefoot and had to sit on the floor.

A photo of inside the OceanGate Expeditions sub, described as around the size of a minivan 

Thin hull made from carbon fibre

Reports from researchers at the University of Houston studied how thin-walled structures can buckle due to tiny imperfections in the materials.

In a paper in the journal of the National Academy of Sciences (PNAS), research lead and professor of civil and environmental engineering, Roberto Ballarini, suggested that imperfections in the carbon fibre used to build the Titan sub's hull could be to blame for the devastating implosion.

Experts have offered different theories as to what could have happened on board the sub

He further suggested that any damage that had built up from the vessel's previous dives could have made it vulnerable to 'micro-buckling.'

Researchers were not able to examine whether micro-buckling was behind the Titan failure - but they looked at vessels of similar shapes and materials.

There are still other theories for why the submarine imploded - including the hull's carbon fibre composite material.

Small imperfections that could go undetected make vessels, like the Titan, at risk of collapsing under intense pressure.

Now that the ship has completely imploded, researchers will likely never determine the exact location of the flaw that caused the tragic event.

Parts 'you can get from Amazon'

Former Royal Navy admiral Chris Parry described the small craft, named Titan, as 'very flimsy and fragile' made of parts you 'can get from Amazon'.

Speaking to Sky News, former rear admiral Chris Parry warned that crafts like Titan 'are essentially kit cars, they're not normal submarines'.

'They're built in an experimental way, and this particular one is, shall we say, built from components you can get off the internet, from Amazon - they're very flimsy, very fragile, and you can't allow a lot to go wrong before you're in danger,' he said.

The Titan suffered a deadly implosion last year that killed five people

A file photo of the Titan submersible before its doomed voyage to the Titanic wreck 

Camping shop lights 

A journalist who once sat inside claimed it features lights from a camping shop, off the shelf CCTV cameras and salvaged metal pipes for ballast.

CBS correspondent David Pogue who descended to see the Titanic last year - compared the sub to something put together by MacGyver - the TV series character known for his ingenuity in making devices from different items to get out of difficult situations.

Recalling the interior of the submersible, he described white camping lights on the ceiling, off-the-shelf security cameras, Ziploc bags for a toilet and construction pipes as ballast.

'The main centre section looks like a shiny white tube about minivan length. It's made of five inch thick carbon fibre which no one has ever used in a submersible before,' he told his Unsung Science podcast. 

Ballast made of abandoned construction pipes 

Speaking to BBC news, CBS reporter David Pogue - who took a trip of the submarine himself - said he was had some doubts over getting in due to 'improvised' elements.

'It's a one-of-a-kind submersible, with five-inch thick carbon fiber,' he explained.

'I have to admit I had some qualms getting on that thing, because a lot of the components are off-the-shelf, improvised – for example you steer the sub with a game controller [like] an Xbox controller.

'Some of the ballast is abandoned construction pipes that are sitting on shelves on the side of the thing, and the way you detach the ballast is you get everybody ob-board to lean to one side of the sub and they roll off,' he explained.

Safety incidents on dives

The Titan sub is shown seconds before submerging with five people onboard

The Titan was hit by technical issues and mishaps on at least six previous occasions before it vanished. 

In August 2021, Arthur Loibl dived down 12,500 feet to the Atlantic wreck site and has said he was 'incredibly lucky' to survive the voyage.

Speaking to German tabloid Bild, the 60-year-old said parts fell off and the mission went into the water five hours late due to electrical problems.

In July 2022, YouTuber Alan Estrada was onboard Titan when the batteries of the sub suddenly drained, forcing it to end early.

Mexican-born Estrada and his fellow submariners' time spent at the wreck was slashed from four hours to one so they could return to the surface before the sub lost power.

Meanwhile, Josh Gates told how the sub 'did not perform well' when he went on a trip to the Titanic in 2021.

He said: 'To those asking, Titan did not perform well on my dive. Ultimately, I walked away from a huge opportunity to film Titanic due to my safety concerns with OceanGate.

'There's more to the history and design of Titan that has not been made public - much of it concerning.'

Billionaire's friend withdrew due to safety worries

A thrill-seeker who intended to join his missing billionaire friend Hamish Harding on the sub pulled out of the dive because he thought OceanGate was 'cutting too many corners'.

Chris Brown, 61, had paid the deposit to go on the doomed voyage, but says he changed his mind after becoming concerned by the quality of technology and materials used in the vessel.

Among his concerns were OceanGate's use of 'old scaffolding poles' for the ballast and the fact that its controls were 'based on computer game-style controllers'.

He told The Sun that despite being 'one of the first people to sign up for this trip', he ultimately decided the 'risks were too high'.

The key mistakes: Experts warned of raft of safety issues in the years before the tragedy

Experts in submersible vehicles wrote a letter warning trips on Titan could end in 'disaster' years before the vessel vanished.

The letter, obtained by the New York Times, warned that 'the current 'experimental' approach' of the company could result in problems 'from minor to catastrophic.

It was sent by the Manned Underwater Vehicles committee of the Marine Technology Society, a 60-year-old trade group.

It is unclear if any employee or Rush himself responded to the letter, and there was no further detail on why the approach was considered dangerous.

Anyone boarding Titan was required to sign a disclaimer that read: 'This experimental vessel has not been approved or certified by any regulatory body and could result in physical injury, emotional trauma, or death.'

For years, a number of red flags over the safety of the Titan submersible had been raised - but were ignored by OceanGate boss Stockton Rush

Delay before sounding the alarm

OceanGate Expeditions was criticised for taking eight hours to tell the US Coast Guard it had lost contact with Titan.

At 2.45pm - an hour and 45 minutes into the dive - it lost contact with its mothership, the Polar Prince.

But it wasn't reported as missing to the US Coast Guard until 10.40pm, eight hours later.

The company has not yet explained why it took so long to alert the Coast Guard when the Titan lost communications.

Dives to the Titanic usually take around eight hours, it is understood. 

No official inspections 

OceanGate opted against having Titan 'classed', an industry-wide practice whereby independent inspectors ensure vessels meet accepted technical standards.

The firm suggested that seeking classification could take years and would be 'anathema to rapid innovation'.

In 2019, OceanGate said seeking classification for Titan would not 'ensure that operators adhere to proper operating procedures and decision-making processes – two areas that are much more important for mitigating risks at sea'.Classification involves recruiting an independent organisation to ensure vessels like ships and submersibles meet industry-wide technical standards.

OceanGate bosses fired David Lochridge, who was Director of Marine operations for the Titan project, in 2018 after it disagreed with his demand for more rigorous safety checks 

It is a crucial way of ensuring a vessel is fit to operate.

In a blog post titled 'Why Isn't Titan Classed?', OceanGate suggested classification would take too long.

The post said: 'While classing agencies are willing to pursue the certification of new and innovative designs and ideas, they often have a multi-year approval cycle due to a lack of pre-existing standards…

'Bringing an outside entity up to speed on every innovation before it is put into real-world testing is anathema to rapid innovation.'