Banging sounds have been detected in the massive search for the missing Titanic submarine as friends of the explorers fear that the five stuck onboard the vessel are running out of time – with the clock ticking to find the craft before it runs out of oxygen tomorrow.

Titan lost communication with tour operators on Sunday while about 435 miles south of St John’s Newfoundland during a voyage to the shipwreck off the coast of Canada.

Five people are onboard, including British billionaire adventurer Hamish Harding, and on Tuesday the US Coast Guard estimated the 22ft long OceanGate Expeditions vessel had just over 40 hours of oxygen left. 

Shahzada Dawood, his son Suleman, 19, OceanGate’s chief executive and founder Stockton Rush and French submersible pilot Paul-Henry Nargeolet, are also stuck in the deep-sea vessel. 

The discovery has sparked fresh hopes that the passengers are still alive and could be banging the side of the craft so that they can be detected on sonar – possibly with cups. But at 12,500ft – nearly two-and-a-half miles – below the surface, and with possibly just two vessels on Earth capable of rescuing them, time is running out to find the craft.

In a heartbreaking plea today, one of Mr Harding’s close friends Jannicke Mikkelsen warned ‘we are losing time’.

The panicked friend told BBC Radio 4’s Today programmer this morning: ‘I’m nervous. I’m sick to my stomach with nerves. I’m terrified, I’m anxious. I’m not sleeping at the moment. I’m just hoping for good news. Every single second, every single minute feels like hours.’

Colonel Terry Virts, another friend who dubbed Mr Harding ‘the quintessential British explorer’, also stressed that ‘the clock is ticking’ to find the five onboard.

Meanwhile retired British navy rear admiral Chris Parry told LBC that hopes of finding the missing deep-sea vessel without an ’emitting signal’ will be ‘impossible’ to find in the timescale. 

Overnight search equipment was seen being loaded onto US aircrafts to be taken to the St John’s area as the frantic search continues 

Five people are onboard, including British billionaire adventurer Hamish Harding

Amongst those on board are Shahzada Dawood, his son Suleman, 19 (pictured together) 

Harding (pictured) is the CEO of Action Aviation in Dubai. He excitedly posted to social media about being there on Sunday. His friends called him the ‘quintessential British explorer’ this morning 

French Navy veteran PH Nargeolet (left) is believed to be taking part in the expedition, along with Stockton Rush (right), CEO of the OceanGate Expedition

Admiral Parry said: ‘I’m afraid the odds are vanishingly small. Obviously, we want to remain hopeful and optimistic but there are two problems here – one is actually finding the thing and secondly is how on earth are you going to get it off the seabed.

‘It’s never been done before and I don’t think anybody’s got any ideas about how to do it at the moment.’ 

Scientist Dr Michael Guillen, who ‘almost died’ when visiting the Titanic wreck in 2000, said following the news of the underwater sounds, that the trapped crew could be using cups to bang on the side of the sub to communicate.

He told Good Morning Britain: ‘If their hydrophone failed so early in the mission, less than two hours down which means they never made it to the bottom, at the very least they could take their cups and bang it on the side of the sub.

‘That’s what I would do if I were down there and I am sure that’s what the pilot will be telling everybody.

‘They have five people, they can make quite a racket by just banging on the side as sound communicates extremely well in water.’

Dr Guillen added that when he heard the news it gave him ‘great hope that perhaps their still alive.’ 

Another friend of the billionaire British explorer said the ‘banging sounds’ is the kind of thing his missing friend would do.

He told BBC Breakfast: ‘That is just the sort of thing I would have expected Hamish to come up with.’

He added: ‘There’s always hope. As an explorer, you never give up anyway.’ 

Scientist Dr Michael Guillen, who ‘almost died’ when visiting the Titanic wreck in 2000 told Good Morning Britain today that the crew could be using cups to bang on the side of the submarine 

Retired British navy rear admiral Chris Parry slammed OceanGate claiming the submarine trip was ‘fundamentally dangerous’ and had ‘no back-up plan’

Banging sounds have been detected in the massive search for the missing Titanic submarine

Last known sighting: The Titan was pictured just before it embarked on the dive into the Atlantic Ocean to view the Titanic shipwreck 

A Canadian Aircraft (file photo) heard ‘banging’ at 30-minute intervals in the area the submarine disappeared, a leaked memo suggests 

Last night search equipment was seen being loaded on to US military plane Horizon Arctic to be taken to the harbour at St John’s to help with the search effort

At 9.45am – 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 5.40pm, eight hours later. Canada ‘s Coast Guard wasn’t alerted until even later – 9.13pm on Sunday night. 

Last night, search equipment was seen being loaded onto US military aircraft Horizon Arctic to be taken to the harbour of St John’s to help with the frantic search.

It comes hours after Canadian aircraft heard noises at 30-minute intervals in the area the capsule vanished. The banging was noted in emails exchanged with the US Department of Homeland Security and seen by Rolling Stone, but it was not clear when they were heard.

Coast Guard officials confirmed underwater noises were heard by a plane and operations were ‘relocated’ to determine the origin. As of early Wednesday, they have ‘yielded negative results’.

Recue crews will further analyze the data, which could be considered for future search plans in the deep Atlantic Ocean since the submersible launched Sunday and quickly lost contact with the surface.

OceanGate has not escaped criticism as the rescue search continues. Admiral Parry slammed the company this morning claiming the submarine trip was ‘fundamentally dangerous’ and had ‘no back-up plan’. 

‘Why on earth you would go in a dodgy piece of technology where you actually have to sign away any right to sue the company for emotional damage, injury or death is beyond me’, he added.

‘It is fundamentally dangerous, there was no back-up plan, it’s experimental and I’m afraid to say there’s an element of hubris if you want to go down and do that.’ 

Cargo being loaded onto the Horizon Arctic so it can be taken to the harbous in St John’s and help with the search efforts 

The ramped up search efforts follow hopeful signs that the Titan five are still alive as banging sounds were heard in 30 minute intervals 

The frantic search comes as the submarine is expected to have around 40 hours left of oxygen 

Richard Garriot de Cayeux, President of The Explorers Club, confirmed in a Tuesday night social media post that ‘there is cause for hope.’

He said in a statement: ‘We have much greater confidence that 1) There is cause for hope, based on data from the field – we understand that likely signs of life have been detected at the site.’ 

Billionaire Hamish Harding, French explorer Paul-Henri Nargeolet, OceanGate CEO Stockton Rush and Shahzada Dawood, 48, a UK-based board member of the Prince’s Trust charity, and his son Sulaiman Dawood, 19, are reported to be the people stuck in the sub. 

The DHS memo on the banging sounds read: ‘RCC Halifax launched a P8, Poseidon, which has underwater detection capabilities from the air,’ the DHS memo read, ‘reported a contact in a position close to the distress position. 

‘The P8 heard banging sounds in the area every 30 minutes. Four hours later additional sonar was deployed and banging was still heard.’

The timing – or cause – of the banging is not revealed by the memo.

Garriot de Cayeux added The Explorers Club are confident the U.S. Coast Guard ‘precisely understand the experienced personnel and tech we can deeply’ and ‘believe they are doing everything possible with all resources they have’.

One of the five men on the ship, Harding, is a founding member of the Board of Trustees for the Explorers Club. 

The group said they have a direct lines to Congress, The Coast Guard, Air Force and Nave and the White House.  

The missing OceanGate submersible, the Titan, lost contact with the mothership during its descent to the shipwreck Sunday morning

A DHS announcement also stated that ‘the Joint Rescue Coordination Centre is working to find an underwater remote-operated vehicle through partner organizations to possibly assist.’ 

A massive search operation remains underway to find the missing OceanGate submersible, the Titan, after it lost contact with the mothership during its descent to the shipwreck Sunday morning.  

Rear Admiral John Mauger, who is helping coordinate the search, said it could be stuck.

‘We don’t have equipment onsite that can do a survey of the bottom,’ Mauger said on Tuesday. 

‘There is a lot of debris, so locating it will be difficult. Right now, we’re focused on trying to locate it.’

Yesterday Admiral Parry likened the bottom of the Atlantic to ‘being in space’, saying: ‘It’s utterly dark down there, and you have also got a lot of mud and other stuff getting swept up. You can only see about 20 feet in front of you with searchlights. There are very strong ocean currents which are pushing you along.’ 

The 21ft submersible has an oxygen supply of up to 96 hours but it is thought the crew of five have just 40 hours of breathable air left

The US Coast Guard is coordinating the enormous search for the missing OceanGate vessel 

The search site is some 900 miles off the coast of Cape Cod, 400 miles southeast of  Newfoundland, Canada. Getting there is a difficult enough feat without finding the missing sub beneath the ocean surface

If the mini-sub lost power, with no working propellers, lights or heating, its five passengers will be in total darkness in temperatures of around 3C (37F) as the doomed craft rolls along the seabed.

Oceanographer and Titanic expert David Gallo said: ‘Where is it? Is it on the bottom, is it floating, is it mid-water? That is something that has not been determined yet. 

‘The water is very deep – two miles plus. It’s like a visit to another planet. It is a sunless, cold environment and high pressure.’

The basic problem is the submersible, Titan, has stopped transmitting signals, making it almost impossible to locate. It is supposed to send a sonar ‘ping’ (radar and GPS not functioning underwater) to mothership Polar Prince every 15 minutes, but the last one was at 9.45am on Sunday – an hour and 45 minutes into the dive as it was floating right above the Titanic.

For some reason, OceanGate Expeditions, the company that runs the tours of the Titanic, took eight hours to call the coastguard Sunday. It was reported to the US Coastguard at 5.40pm, and Canada’s Coastguard was alerted even later, at 9.13pm.

The vessel’s oxygen supply was estimated at 96 hours, which gives rescue teams until Thursday morning to find the vessel.

TIMELINE OF EVENTS: The Titan lost contact with the surface sparking panic. All timings given in BST, five hours ahead of EST. 

As families wait in agony for news, OceanGate, who started dives to the Titanic in 2021, is facing questions after it emerged the Titan suffered electrical damage and had to be rebuilt for not being able to withstand the ocean before it vanished.

The tourist company responsible for the missing submersible also took eight hours to report it to the Coast Guard after it lost contact an hour and 45 minutes into its descent on Sunday, the DailyMail.com revealed yesterday.

By yesterday, a fleet of US and Canadian rescue ships and aircraft had swarmed to the scene, along with a growing number of private vessels.

Speaking at search headquarters in Boston, Captain Jamie Frederick of the US Coastguard announced: ‘Those search efforts have not yielded any results.’

But last night some of the commercial vessels with specialist underwater drones were sending them down. Frederick offered his ‘most heartfelt thoughts and prayers’ to the lost crew and their loved ones, and pledged they were doing ‘everything possible’. But he admitted the rescuers were entering the final hours.

When he was asked ‘Even with that amount of time left, if you were to find the submersible at this moment, would that give you enough time to save those five people on board?’ he replied: ‘I don’t know the answer to that question. All I know is we will do everything within our power to effect a rescue.’

The Titanic wreckage lies at 12,500ft, and Titan was one of the only craft in the world capable of reaching it. Even nuclear submarines cannot safely go that deep. Deep water dive specialists are assisting coastguards in the ‘unique and challenging’ operation, said Frederick.

Standing on a dockside, he told reporters: ‘Getting salvage equipment on scene is a top priority. It is very heavy equipment, it is very complex, but the best experts are on scene. If the sub is located, the experts will look at the best course of action for recovering the sub.’

Among the equipment is a decompression chamber for the five passengers should they be brought to the surface.

A thrill-seeker who intended to join billionaire Hamish Harding on the missing Titanic sub pulled out of the dive because he thought OceanGate was ‘cutting too many corners’, it has emerged.

Chris Brown, 61, paid the deposit to go on the doomed voyage but said he changed his mind after becoming concerned by the quality of technology and materials used in the vessel, The Sun reported Tuesday night. 

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 newspaper that despite being ‘one of the first people to sign up for this trip’, he ultimately decided the ‘risks were too high’.

Brown added he felt ‘really upset about Hamish’, who is among the five passengers on the submersible, called the Titan, that are currently missing.

Harding had posted about going on the trip before the Titan was put in the water and later lost contact with the surface

Brown and Harding signed up for the voyage after sharing a ‘few beers’ while holidaying on Sir Richard Branson’s Necker Island.

The pair paid the 10 percent deposit for the trip, which has since more than doubled in price, while the Titan was still being developed, he claimed.

But Brown alleged that in the years that followed, he learned OceanGate had ‘missed key targets’ when depth-testing the submersible.

The multi-millionaire digital marketing tycoon found it concerning that the vessel was controlled by a modified Playstation controller.

He also is understood to have been worried by the technical issues and delays throughout the development process.

He told The Sun: ‘I found out they used old scaffolding poles for the sub’s ballast.

‘If you’re trying to build your own submarine you could probably use old scaffold poles. But this was a commercial craft.’

Brown, who said he is ‘not one to shy away from risk’, eventually emailed OceanGate and asked for a refund.

He is worried for his friend but said Harding is not the panicking type. He believes the billionaire is likely keeping ‘extremely calm’ and ‘processing plans, schemes and ideas through his enormous brain’.

Brown said Harding will be ‘giving hope’ to the other passengers.

The Titan vessel will have a carbon dioxide scrubber on board to remove excess toxic gas that builds up when passengers exhale in the confined space, but in most craft it has a limited capacity. There is also a risk of hypothermia due to the low temperatures in the depths of the ocean, as well as hyperventilation induced by panic attacks, which can use up more valuable oxygen

The Titan vessel that is still missing will have a carbon dioxide scrubber on board to remove excess toxic gas that builds up when passengers exhale in the confined space, but in most craft this will have a limited capacity 

A US Navy veteran warned of the chilling health effects of being trapped in a submarine just weeks before the Titanic tourism sub went missing, DailyMail.com can reveal.

In a scientific paper published in a medical journal last month, Dr. Dale Molé, the former director of undersea medicine and radiation health for the US Navy, detailed the ‘hostile’ environment onboard commercial submersibles, with passengers facing depleting oxygen supplies, toxic carbon dioxide levels and plummeting temperatures.

The Titan vessel that is still missing will have a carbon dioxide scrubber on board to remove excess toxic gas that builds up when passengers exhale in the confined space, but in most craft, those have a limited capacity.

A scrubbing system removes carbon dioxide from the atmosphere, making the air safe to breathe. 

Speaking to DailyMail.com Tuesday, Molé said it is ‘very much’ a race against time to rescue the passengers, if they are not already dead from a ‘catastrophic rupture of the pressure vessel.’

He added: ‘Anytime humans are confined in an airtight space, most people may think of oxygen, but carbon dioxide is actually a bigger concern.

‘In a submersible, they’ll have some system of scrubbing carbon dioxide. If they lost battery power, then that system would no longer work.’

There is also a risk of hypothermia due to the low temperatures in the depths of the ocean, as well as hyperventilation induced by panic attacks, which can use up more valuable oxygen. 

Cargo being loaded onto the Horizon Arctic at the harbour in St John’s, bound for the search area

Marc Hagle, 74, and his wife Sharon, 73, went to space on Blue Origin’s fourth trip, in March 2022. They intended to visit the Titanic wreck with OceanGate, and paid in 2017, but sued in February this year for fraud

It has also emerged that a Florida couple sued the Rush, CEO of the Titanic tourism company OceanGate Expeditions, accusing him of misleading them about their trip to visit the wreck and refusing to refund their $210,258 when they complained.

Marc and Sharon Hagle, who made their fortune in commercial real estate, are well known for their philanthropy and their adventurous spirit. In March 2022, they were on the fourth Blue Origin passenger space flight and became the first married couple to become space tourists.

In 2016, while on a trip to the South Pole, they decided their next adventure would be underwater. In 2017 they were announced as among the first customers for OceanGate, which was founded in 2009 by Seattle-born aviator and businessman Stockton Rush, now 61.

But they never got to take their trip, and in February this year sued Rush, accusing him of selling the adventure knowing it was not on schedule, and refusing to refund their cash.