USS Connecticut: How did a $3 billion US Navy submarine hit an undersea mountain?


The Connecticut is now pierside at a US Navy base on the Pacific island of Guam. The Navy says it got there — more than 1,800 miles (2,900 kilometers) east of the South China Sea — under its own power and its nuclear reactor was not harmed, although 11 of its crew of suffered minor injuries in the collision.

The Pentagon has not released details of the damage the vessel incurred nor how long it might be out of action in a region which, with the rise of the Chinese navy, is seeing growing demands on the US fleet.

Which leaves US military planners with some big questions to answer in the coming weeks and months.

Not the least of which is, how did this happen?

Driving a submarine

The Navy on Thursday gave a hint of what might have led to the accident when it relieved the Connecticut’s leadership of their command due to loss of confidence.

The commanding officer, Cmdr. Cameron Aljilani, was relieved of duty, as were the executive officer, Lt. Cmdr. Patrick Cashin, and the chief of the boat, Master Chief Sonar Technician Cory Rodgers.

Vice Adm. Karl Thomas, commander of US 7th Fleet, determined that “sound judgment, prudent decision-making and adherence to required procedures in navigation planning, watch team execution and risk management could have prevented the incident,” according to a statement about the decision.

The undersea environment is unforgiving and even small mistakes can have huge consequences.

“Submarining is hard, it’s really hard. Not everything goes right all the time,” said Thomas Shugart, who spent more than 11 years on US submarines, including commanding an attack sub.

Members of the crew sit at the controls aboard the Seawolf-class attack submarine USS Jimmy Carter in 2005.

Surface ships or a sub operating at periscope depth can relay on global positioning satellites to give sailors a very accurate location, said Shugart, now an adjunct senior fellow at the Center for a New American Security.

But at depth, the GPS systems are not available. Submariners use their compasses and charts.

Accurate charts (with a resolution of 328 feet or 100 meters) of the sea bottom are compiled by sending surface ships over an area and bathing the bottom in sound waves — a method called multi-beam sonar.

But the process is expensive and time consuming, leaving as much as 80% of Earth’s seafloor unmapped.

In the busy South China Sea, through which a third of the world’s maritime trade passes and where China has been building and militarily fortifying man-made islands, less than 50% of the sea bottom has been mapped, David Sandwell, a professor of geophysics at Scripps Institution of Oceanography in California, told CNN.

“It’s not surprising that you could run into something,” he said.

The US Navy has not said exactly where the Connecticut hit the seamount.

Officially, the service says it was in Indo-Pacific waters, but US defense officials had previously told CNN it occurred in the South China Sea.

Sandwell tried to narrow down the area.

Using a method called vertical gravity grading — taking satellite altimetry measurements of the Earth’s gravitational field — and overlaying those results with mapping of the bottom of the South China Sea, he was able to identify 27 places where the Connecticut could have hit a seamount that was not on US Navy charts.

“These are places where the gravity predicts there is something shallower than 400 meters (1,312 feet), around the depth where a submarine might run into it,” he said.

Officially, the Navy says Seawolf-class subs have a maximum depth of more than 243 meters (800 feet), although some experts put their maximum depth around double that.

Submarines do have their own sonar, but using it comes at a price — loss of stealthiness.

Those sonar pings — so ubiquitous in submarine movies — also give away the sub’s position to opposing forces.

“Sonar is your only way to look at the bottom, but you don’t want to put out more sound than you have to,” Shugart said.

“You’d have to do that about every 20 seconds or so,” to get an accurate picture, Sandwell said. “It makes a lot of noise.”

When it comes to knowing the terrain beneath them, even astronauts might have it easier than submariners, according to Shugart.

“Basically, the surface of the moon is better charted than the bottom of the ocean is,” he said.

A history of submarine groundings

The USS Connecticut isn’t the first US Navy sub to be involved in an underwater collision.
The attack submarine USS San Francisco sits in dry dock, on January 27, 2005, in Apra Harbor, Guam to assess damage sustained after running aground approximately 350 miles south of Guam on January 8, 2005.

On January 8, 2005, the USS San Francisco, a Los Angeles-class attack submarine, struck a seamount about 350 miles (563 kilometers) south of Guam in the Pacific Ocean.

The incident killed one sailor and injured 97 others among the crew of 137.

A Navy investigation concluded the San Francisco was traveling at maximum speed at a depth of 525 feet (160 meters) when it hit the seamount, which was not on the chart the sub’s commanders were using at the time.

But the probe found the commanders should have known the undersea mountain was there based on other charts in their possession, which indicated a navigational hazard in the area.

“If San Francisco’s leaders and watchteams had complied with requisite procedures and exercised prudent navigation practices, the grounding would most likely have been avoided,” the Navy report said. “Even if not wholly avoided, however, the grounding would not have been as severe and loss of life may be been prevented.”

Other incidents have been less serious but illustrate the difficulties of maneuvering subs even in familiar waters.

For instance, in November 2015, the USS Georgia, an Ohio-class guided missile submarine, struck a channel buoy and grounded as it was returning to port in Kings Bay, Georgia.
The Ohio-class guided-missile submarine USS Georgia departs Naval Submarine Base Kings Bay in 2015.

The 18,000-ton, 560-foot-long (170 meters) sub sustained more than $1 million in damage and its captain was relieved of command.

And in 2003, the USS Hartford ran aground while entering a NATO base in Spain, resulting in a $9 million repair bill and its commander being relieved of duty.

Despite those incidents, Shugart, the former US Navy sub commander, defends the US Navy’s record under the sea.

“We have more submarines, they spend more time at sea, they go a lot farther away from home and they operate at higher speeds than probably anybody else’s,” he said.

“We do the most challenging submarine missions that anybody does and the farthest away from home,” he said, adding: “even the pros have bad days.”

What makes the USS Connecticut so special?

The Connecticut is one of three Seawolf-class submarines in the US Navy fleet, each costing about $3 billion to build. The 9,300-ton, 353-foot sub, commissioned in 1998 and is crewed by 140 sailors.

What are nuclear-powered submarines and how do they work?

Like all modern US Navy attack submarines, the Connecticut is powered by a nuclear reactor, which enables it to be fast but quiet, with none of the noise produced by a combustion engine. Nuclear power enables such subs to stay at sea and underwater as long as provisions for the crew hold out.

The Navy doesn’t give exact figures in publicizing the abilities of its submarine, but experts say the Seawolf-class is exceptional.

“These subs have some of the most advanced — in fact the most advanced — underwater capabilities in the business,” said Alessio Patalano, professor of war and strategy at King’s College in London.

The Navy says it is “exceptionally quiet, fast, well-armed, and equipped with advanced sensors.”

A Navy fact sheet says the Connecticut is capable of going faster than 28 mph (46.3 kph) under water. That’s faster than the average container or cargo ship on the surface of the sea and almost as fast as the US Navy’s Arleigh Burke-class destroyers.

As it is larger than even the newest Virginia-class attack subs, the Connecticut can carry more weaponry than other US attack submarines — including up to 50 torpedoes as well as Tomahawk cruise missiles, according to a US Navy fact sheet.

The USS Connecticut was commissioned in Groton, Connecticut on December 11, 1998.

And despite being more than 20 years old, it’s also technologically advanced with updates to its systems performed during its service life.

Though the Navy doesn’t give details on the missions its submarines undertake, the three Seawolf-class subs are thought to be important intelligence-gathering assets, especially in shallower environments.

“The robust design of the Seawolf class enables these submarines to perform a wide spectrum of crucial military assignments — from underneath the Arctic icepack to littoral regions anywhere in the world,” the manufacturer, General Dynamics Electric Boat, says on its website.

“Their missions include surveillance, intelligence collection, special warfare, cruise missile strike, mine warfare, and anti-submarine and anti-surface ship warfare,” Electric Boat says.

With no combat taking place in the South China Sea, the focus of the sub in the current environment is likely to be in intelligence gathering.

And that’s why China is paying close attention.

The  guided-missile destroyer USS John S. McCain, rear, and the Royal Australian Navy  frigate HMAS Ballarat sail together during integrated operations in the South China Sea in October 2020.

Questions from Beijing

Following the collision, Beijing has accused Washington of not being forthcoming about what happened and how it could affect countries around the South China Sea.

“We have repeatedly expressed our grave concern over the incident and asked the US side to take a responsible attitude and provide a detailed clarification so as to give a satisfactory account to the international community and countries in the region,” Chinese Foreign Ministry spokesperson Wang Wenbin said this week.

The subject of nuclear-powered submarines has been prominent in Chinese state media over the past few months in the wake of Australia’s decision to acquire such vessels from the United States and the United Kingdom under a deal known as AUKUS.

Chinese Foreign Ministry spokesperson Zhao Lijian said in September the AUKUS deal “seriously damages regional peace and stability.”

The Connecticut incident just added fuel to Beijing’s propaganda push.

Washington issued its first public statement on the collision five days after it occurred. It did not disclose the fact that the Connecticut hit a seamount until earlier this week, nearly a month after the incident.

US Navy officials told CNN on Wednesday the delays stemmed from concerns including keeping the damaged sub safe and ensuring a thorough investigation of the incident, as is standard.

“Due to operations security, we could not disclose the location of the submarine or the incident to the public at an earlier date,” Cmdr. Hayley Sims, a public affairs officer for the US 7th Fleet, said in an email.

Sims said two internal investigations were launched, one on the command of the sub and a second on safety procedures.

Analysis: Why Russian and Chinese warships teaming up to circle Japan is a big deal

The first, she said, “determined USS Connecticut grounded on an uncharted seamount while operating in international waters in the Indo-Pacific region” and has been submitted to 7th Fleet commanders for review.

The second probe, being conducted by Submarine Force, US Pacific Fleet in Hawaii, is ongoing.

A spokesperson for the sub force, Cmdr. Cindy Fields, told CNN this week the submarine is in “a safe and stable condition” at the port in Guam.

“USS Connecticut’s nuclear propulsion plant and spaces were not affected and remain fully operational,” she said.

The Navy said Thursday the Connecticut would be moved to Bremerton, Washington, for repairs.

According to a report by the state-run Xinhua news agency, Chinese Foreign Ministry spokesman Wang called on Washington to clarify “the intended navigation of the nuclear submarine, whether the specific location of the incident was in an exclusive economic zone or territorial sea of any other country, or whether the incident has caused nuclear leakage or damaged the marine environment.”

The US has not revealed any of those details, but when it comes to the South China Sea, Washington’s policy is consistent.

After a US destroyer performed a freedom of navigation operation in the waterway in September, a US 7th Fleet statement responded definitively to Chinese objections: “The United States will continue to fly, sail, and operate wherever international law allows,” the statement said. “Nothing (China) says otherwise will deter us.”

CNN’s Oren Liebermann and Barbara Starr contributed to this report.



Source link

Damaged US Navy sub was operating in one of world’s most difficult undersea environments, analysts say


By Brad Lendon, CNN

The US Navy submarine that struck an underwater object in the South China Sea last weekend was operating in one of the world’s most difficult undersea environments, one filled with noise from ships above and a seabed with constantly shifting contours that can surprise any submarine crew, analysts say.

US defense officials on Thursday did not give details of the accident that befell the USS Connecticut, saying only that a number of sailors aboard were injured when the sub struck an object while running submerged in the South China Sea.

The service said the injuries were minor and the sub was making its way to the US naval base on the island of Guam under its own power.

The Connecticut is one of three Seawolf-class submarines in the Navy fleet, with a price tag of about $3 billion each. The 9,300-ton, 353-foot sub, commissioned in 1998, is powered by a single nuclear reactor and crewed by 140 sailors.

As it is larger than even the newest Virginia-class attack subs, the Connecticut can carry more weaponry than other US attack submarines — including up to 50 torpedoes as well as Tomahawk cruise missiles, according to a US Navy fact sheet.

And despite being more than 20 years old, it’s also technologically advanced with updates to its systems performed during its service life.

The Navy says it is “exceptionally quiet, fast, well-armed, and equipped with advanced sensors.”

“These subs have some of the most advanced — in fact the most advanced — underwater capabilities in the business,” said Alessio Patalano, professor of war and strategy at King’s College in London.

How did it get into trouble in the South China Sea?

While the Navy hasn’t revealed what the Connecticut struck, analysts say conditions in the South China Sea can be a challenge for the sub’s sophisticated sensors.

“It could have been an object small enough to be missed by sonars in a noisy environment,” Patalano said.

According to the US National Oceanic and Atmospheric Administration, naval vessels use what is called “passive sonar” to detect objects in the water around them. Unlike “active sonar,” which sends out pings and then registers how long their echoes take to return to the vessel, passive sonar detects only sound coming toward it.

This enables the submarine to stay quiet and hidden from adversaries, but it means subs must rely on other devices or multiple passive sonars to triangulate the location of an object in its path.

Because the South China Sea is one of the world’s busiest shipping lanes and fishing areas, all kinds of noises from vessels on the surface can mask what might pose a danger to the submarine below, analysts said.

“Depending on the place the incident occurred, noise interference of sorts (usually from traffic above) might have affected sensors, or indeed operators’ use of them,” Patalano said.

And it’s not just shipping that can pose problems for a submarine in the South China Sea, said Carl Schuster, a former US Navy captain and past director of operations at the US Pacific Command’s Joint Intelligence Center.

“It is an area with a very poor acoustic environment,” Schuster said, with even the nature of the waters themselves creating problems.

“Ambient noise from currents passing between the islands and inconsistent water conditions affect acoustic reception,” he added.

It’s also possible that something from below could have caused a problem, Schuster said.

“Those waters’ environment and the sea bottom are in a state of slow but inexorable change,” Schuster said. “It is an area that requires constant bottom contour mapping. You can hit an uncharted underwater mountain down there.

“That’s why the countries in that region, the US and China are constantly surveying and patrolling them.”

The accident was the second involving a submarine in the region this year. In April, an Indonesian submarine sank in the Bali Strait, killing all 53 crew aboard.

Indonesian Navy officials said the accident was caused by “a natural/environment factor,” but did not give further details.

The-CNN-Wire
™ & © 2021 Cable News Network, Inc., a WarnerMedia Company. All rights reserved.



Source link

Putin’s stealth subs could cripple Britain by cutting undersea internet cables as Russia launches new Arctic front


VLADIMIR Putin’s shadowy fleet of submarines dedicated to tampering with vital undersea internet cables could cripple Britain and plunge the country into chaos.

The vessels are operated by a shadowy branch of the Russian military that answers directly to Putin – with a mission to deliver a catastrophic blow to the West.

5

The subs are carried underneath beneath an enormous “mothership” undersea vessel and are built to lurk at the bottom of the ocean – entering the Atlantic by sailing down from the Arctic.

They then use robotic arms to tamper with or even cut key cables that help keep the world’s economy moving with potentially devastating consequences.

It comes as Putin has opened up a new front in the North Pole as he builds new military bases in the frozen wastes – giving him control of polar waters across 11 of the world’s time zones.

Tensions continue to simmer between the West and Russia who have both beefed up their presence in the polar region, which is believed to hold significant natural resources.

And cutting the undersea cables could be a key element in any conflict between the two sides.

Undersea cables crisscrossing the seafloor carry 97 per cent of internet traffic with $10 trillion worth of daily financial transactions dependent on them.

Cutting enough of the network in the Atlantic could cause chaos for Britain, with Air Marshall Sir Stuart Peach previously warning such a breach could be “catastrophic”.

It could shut down the internet, cut Britain off from the rest of the world, paralyse financial transactions, and damage communications with the military overseas.

And the US is also under threat, with a report Director of National Intelligence urging Washington to push for stronger protections for the undersea cables.

The US Government is reliant on the cables to transfer information with their NATO allies – and as well as cutting them, its also feared Russia or other state actors could tap into the cables to steal information.

Defence expert Rob Clark from the Henry Jackson Society told The Sun Online “the threat is very real” from the secretive Russian subs.

“Their aim is to retain the credible capability either to disrupt or destroy the cables that the UK’s economy and its entire communications rely on,” he warned.

“Even slightly damaged that can cause untold chaos and disruption to the UK.”

And the cables are not hard to find, with their locations being open to the public as global shipping networks have to be aware of their locations.

The dire warning comes as it emerged the threat is being taken so seriously that the Royal Navy has recently ordered a special surveillance ship to protect cables from the Russians.

And one US submariner even described to The Sun Online how he witnessed the Russians practicing lifting the cables in a dress rehearsal for cutting them during any showdown with the West.

A rare picture of what is believed to a Losharik submarine, launched from the Belgorod

5

A rare picture of what is believed to a Losharik submarine, launched from the Belgorod
The giant Belgorod 'mothership' submarine

5

The giant Belgorod ‘mothership’ submarineCredit: Getty – Contributor

The concentration of cables in chokepoints means any disruption is likely to hit hard, as an earthquake under the Luzon Strait between Taiwan and the Philippines showed in 2006.

The quake severed six out of the seven cables used to distribute internet and phone services from North America to Taiwan, China, Hong Kong, Japan, Singapore and South Korea.

That led a 100 per cent internet outage to Hong Kong and South East Asia, cutting off millions of citizens and businesses from internet and mobile phones.

It has been estimated that cutting three cables could lead to some countries losing 70 per cent of their data traffic.

‘CRIPPLING BLOW’

The impact of any outage on that scale would severely damage the world financial system.

Globally, it has been estimated an average of 15 million transactions a day are wholly reliant on undersea cables alone.

Now Chancellor Rishi Sunak MP penned a paper on the threat in 2017 in which he warned of “full-scale outages” caused by the cable cutting and coordinated sabotage is a “major threat to the UK”.

“A successful attack would deal a crippling blow to Britain’s security and prosperity,” he wrote.

Putin’s mysterious cable cutting submarines

RUSSIA is believed to have six submarines dedicated to the cable cutting mission – with the Losharik the most modern and capable.

Only a handful of grainy photographs exist of the vessel and everything known about it comes from educated guesswork.

A fire on board Losharik in 2019 resulted in the deaths of 14 submariners, reportedly including some of the most experienced decorated in the Russian navy.

The Kremlin has never explained what the submarine was doing just 60 miles off the coast of Norway in the first place.

According to submarine expert H.I Sutton, who writes the Covert Shores blog, the submarine is constructed from seven spherical titanium hulls strung together which gives it extraordinary strength.

The vessel is named after a Russian cartoon horse, which is made up of lots of many spheres joined together.

It can operate at up to depths of 3300ft, far greater than conventional submarines and have special attachments allowing them to rest at the bottom of the sea.

The submarines are deployed from the giant Belgorod, itself designed for special operations, and currently the longest submarine currently serving in the world’s navies.

Mr Clark said disrupting the undersea cables rather than completely destroying them would fit into Vladimir Putin’s goal of goading the West.

“A more likely scenario would be to disrupt the cables rather than destroy them,” he said.

“What should be the response to this? Should we torpedo the submarine or launch a cyber-attack on the Moscow stock exchange?

“Because of that Russia will try to exploit it because they know it’s a weakness.

‘Destroying them would be such a provocation from Russia the likes of which we’ve never seen since the Cold War, even compared to the Salisbury attack.

“So disrupting them is a much more likely scenario. So for example if there was an escalation of UK commitment to the Ukraine, where the British army and Royal Navy are training, then that would a response from Russia.”

The subs are directly controlled by Vladimir Putin

5

The subs are directly controlled by Vladimir PutinCredit: AFP

The Russian’s tactics were first deployed during the Cold War and they have been refining them ever since.

Former US submariner Aarron Amick. witnessed the cable cutting subs in action firsthand while working as a sonar operator off the coast of Norway.

“We were monitoring a unit around the coast of Norway when they sent out a mothership, which was a specially modified ballistic missile submarine that had the missiles removed,” he told The Sun Online.

“The area where the missiles were was basically a hanger for a second mini-sub, which they would dock in the belly and they would go down the coast of Norway, which very convenient as it was the closest country with cables.

“They would undock the sub and it would dive very deep, practically to the bottom to locate where these cables where so they could go right to them.

“They would also practice picking them up, not necessarily damage them because it was peacetime, but give them experience in doing everything except that.”

Undersea cables carry 97 per cent of the world's internet traffic

5

Undersea cables carry 97 per cent of the world’s internet trafficCredit: Alamy

Vulnerable undersea cables – the width of a garden hosepipe

THE FIRST cable was laid across the Atlantic 1858 and have been at the heart of global communication ever since.

They are mostly operated by private companies with Google recently announcing plans to install a cable linking the US, UK and Spain that would come ashore in Cornwall.

Most cables are around 3cm in diameter, roughly the size of a hosepipe and are cased in galvanised steel armour with a plastic coating.

Data is transmitted down the optical fibres as wavelengths of light travelling at about 180,000 miles per second.

Each fibre has the capacity to transmit as much as 400GB of data per second – about enough for 375 million phone calls.

A single undersea cable can contain anywhere between four and 200 of these fibres.

With so much of the world now dependent on the internet, they have also seen as an Achilles heel.

The idea of tampering cables as a weapon of war was developed by the British in World War One, when German communications were intercepted and its cables cut.

But the Russians have in recent years been seen as a looming menace, building on methods from the Cold War.

When he was an MP, the current Chancellor Rishi Sunak warned about the threat in hard hitting report.

“A successful attack on the UK’s undersea cable infrastructure would be an existential threat to our security,” he said.

He said the US Navy crew observed the operation over a three months and said he was “impressed” by the Russian’s capability.

 “I was doing my job and being professional but in the back of my mind was impressed. At the time the American navy had none of this capability.

“It’s fantastic that this thing goes and this activity continues today.”

Navy warfare expert Sidharth Kaushal from defence think-tank RUSI said the submarines are operated by the GUGI or Directorate for Deep Sea Research, which answers to Putin.

“They’ve been developing a variety of special purpose submarines which are deep diving and have the capacity to withstand very deep pressures,” said Dr Kaushal.

“They could be used for a wide range of activities from tapping into the cables to gather intelligence to severing them to cause economic disruption in an extreme scenario.”

He said cutting cables “fits well” into a Putin’s strategy for fighting the West.

“He knows his conventional forces are inferior to Nato so the emphasis is to impose as much disruption to Western society to convince them the game isn’t worth the candle,” he said.





Source link

World's Most Powerful & Deadly Super Submarine – USS Texas – Full Documentary



World Most Feared Super Submarine in U.S, Navy – The Virginia Class attack submarine is the U.S. Navy’s newest undersea warfare platform and incorporates the latest in stealth, intelligence gathering and weapons systems technology. Attack submarines are designed to seek and destroy enemy submarines and surface ships; project power ashore with Tomahawk cruise missiles and Special Operation Forces; carry out Intelligence, Surveillance, and Reconnaissance (ISR) missions; support battle group operations; and engage in mine warfare.

The Virginia class wa not the first new design to come into service after the Cold War. The Seawolf class was originally intended to succeed the Los Angeles class, but production was canceled after only three submarines were produced. This restriction occurred due to budgeting restraints at the end of the Cold War, and the final submarine was manufactured in 1995. At a cost of $3 billion per unit, the Seawolf class was the most expensive SSN submarine. The Virginia class was put into production in full swing due to being smaller and carrying more manageable costs than the Seawolf.

The Navy is now building the next-generation attack submarine, the Virginia (SSN 774) class. The Virginia class has several innovations that significantly enhance its warfighting capabilities with an emphasis on littoral operations. Virginia class SSNs have a fly-by-wire ship control system that provides improved shallow-water ship handling. The class has special features to support special operation forces including a reconfigurable torpedo room which can accommodate a large number of special operation forces and all their equipment for prolonged deployments and future off-board payloads.

The class also has a large lock-in/lock-out chamber for divers. In Virginia-class SSNs, traditional periscopes have been supplanted by two photonics masts that host visible and infrared digital cameras atop telescoping arms. With the removal of the barrel periscopes, the ship’s control room has been moved down one deck and away from the hull’s curvature, affording it more room and an improved layout that provides the commanding officer with enhanced situational awareness. Additionally, through the extensive use of modular construction, open architecture, and commercial off-the-shelf components, the Virginia class is designed to remain state of the practice for its entire operational life through the rapid introduction of new systems and payloads.

As part of the Virginia-class’ third, or Block III, contract, the Navy redesigned approximately 20 percent of the ship to reduce their acquisition costs. Most of the changes are found in the bow where the traditional, air-backed sonar sphere has been replaced with a water-backed Large Aperture Bow (LAB) array which reduces acquisition and life-cycle costs while providing enhanced passive detection capabilities. The new bow also replaces the 12 individual Vertical Launch System (VLS) tubes with two 87-inch Virginia Payload Tubes (VPTs), each capable of launching six Tomahawk cruise missiles. The VPTs simplify construction, reduce acquisition costs, and provide for more payload flexibility than the smaller VLS tubes due to their added volume.

United States Navy (USN).
Virginia-class Nuclear-powered fast attack Submarine: USS TEXAS (SSN 775),
Namesake: State of Texas,
Commissioned: 2006, Builder: Newport News Shipbuilding,

source