Here's What You Need to Know: Submarine collisions are far from isolated incidents.

On May 23, 1981 the Soviet submarine K-211 Petropavlovsk cruised quietly at nine knots, one hundred and fifty feet below the surface of the Arctic Barents Sea. The huge 155-meter-long Delta III (or Kalmar)-class submarine was distinguished by the large boxy compartment on its spine which accommodated the towering launch tubes for sixteen R-29R ballistic missiles, each carrying three independent nuclear warheads. 

K-211’s mission was hair-raisingly straightforward: to cruise undetected for weeks or months at a time, awaiting only the signal that a nuclear war had broken out to unleash its apocalyptic payload from underwater on Western cities and military bases up to four thousand miles away.

British and American nuclear-power attack submarines (SSNs), or “hunter-killers,” were routinely dispatched to detect Soviet ballistic missiles subs (SSBNs) leaving from base to discreetly stalk them. The quieter SSNs also awaited only a signal of war, an event in which they would attempt to torpedo the Soviet subs before they could unleash their city-destroying weapons.

Mindful of this threat, at half past seven that evening K-211’s commander halted his sub and pivoted it around so that its MGK-400 Rubikon bow sonar array could attempt to pick up any submarines sneaking behind it in the ‘blind spot’ of its wake—a maneuver known as “clearing the baffles.” However, the SSBN’s hydrophones did not report any contact.

In his book Hunter Killers: The Dramatic Untold Story of the Royal Navy’s Most Secret Service, Iain Ballentyne described what happened shortly afterwards:

“…at 19.51, the Soviet SSBN juddered as she sustained three short glancing impacts astern and from below, each lasting only a few seconds.

Immediately ordering the boat to periscope depth, the Delta III’s sonar team detect propeller noise on a bearing 127 degrees.  The contact was judged to be a submarine.

Having ascended to achieve separation, K-211 also turned to starboard, but the contact was lost within a couple of minutes.”

The Soviet submarine surfaced and found that something had scraped off the rubber sound-dampening anechoic tiles lining the submarine’s stern and damaged its rear hydroplane.  Furthermore, fragments of metal—undoubtedly from a Western submarine—were embedded in its right screw and even had punctured its rear ballast tank. K-211’s right screw had to be replaced and its rear stabilizing fin repaired.

A Soviet investigation subsequently concluded the metal had likely come from a U.S. Navy Sturgeon-class attack submarine ascending from below and to the rear.

The Soviet commission might have been highly interested in British press reports later that year that the Royal Navy’s hunter-killer submarine Sceptre had returned to base in Devonport with damage from a collision from a “detached glacier.”

Only a decade later in September 1991, the Sceptre’s former weapons officer David Forghan described very different circumstances for the accident when interviewed on the television program This Week.

Sceptre, or SS-104, was the fourth of six Swiftsure-class nuclear-powered attack submarines launched by Vickers in the 1970s. The Swiftsures were shorter at 83 meters and broader than the UK’s first-generation Churchill-class SSNs, and boasted retractable diving fins on their bows instead of on their conning towers. All but the lead ship used a shrouded pump-jet propulsor instead of a conventional propeller for quieter running, and had their internal mechanisms isolated with rubber to further decrease acoustic signature. 

That May, the Sceptre had been trailing K-211 for some time using her Type 2001 sonar, which had an underwater detection range twenty-five to thirty miles or six to seventeen miles while moving fast, when it abruptly lost its sonar contact—around when K-211 shifted its position to clear its baffles. The British submarine continued cruising ahead when its bow smashed into K-211’s tail from below. 

One of the Soviet submarine’s five-bladed propellers chewed into the front hull casing of the Sceptre, tearing a 23-foot long chunk off its bow and ripping off the front of its conning tower.

In The Silent Deep, by James Jinks and Peter Hennesy, one officer recalled:

“It started very far forward, sort of at the tip of the submarine, and it trailed back. It sounded like a scrawling. We were hitting something. That noise lasted for what seemed like a lifetime. It was probably on a couple of seconds or so. Everybody went white.”

Normally, such damage would have triggered an automatic shutdown of the submarine’s reactor, but Sceptre’s captain engaged a ‘battle short’—a manual override of the safety system for emergencies—to keep his 5,500-ton submarine under control. Emergency bulkheads were sealed as the wounded submarine fled the scene, believing itself to be pursued by a Soviet submarine for two days.

Chief Petty Officer Michael Cundell recounted in The Silent Deep, “We just made a sharp exit and escaped under the ice without a trace.” 

Upon finally surfacing, the British submariners discovered the horrifying extent of the damage, as Cundell described:

“That tear started about three inches from the forward escape hatch [Cundell]. If that hatch had been hit or damaged—it’s about 2’6” in diameter—if that had been ruptured, then the fore ends would have shipped water which would have made the boat very heavy. We would have probably sunk.’

Sceptre limped back to its home base of Devonport at night to conceal the damage, its scars camouflaged with a fabric shroud and black paint applied by the crew. 

In port, fragments from the Russian propeller that had partially penetrated the pressure hull had to be removed. The Royal Navy meanwhile peddled the glacier-collision story to the media.

After months of repairs, Sceptre finally returned to the sea that fall, now under Captain Doug Littlejohns. In the wake of the terrifying accident, he recalled, “The submarine was broken and so was the crew.” To build back crew confidence, he took them out on a white-knuckle practice run performing deep dives and fast maneuvers.

Both K-211 and Sceptre served roughly three more decades after the accident. K-211 remained part of Russia’s smaller SSBN fleet until she was decommissioned in 2013, when the first new pump-jet propelled Borei­-class began to replace the older Deltas. K-211’s nuclear fuel was finally removed in December 2018, and she was moved to Bolshoy Kamen for scrapping in 2019.

Sceptre was involved in several notorious accidents, suffering an onboard fire, snagging Swedish fishermens’ nets, and leaping out of her cradle in port during an engine test. Her pump-jet propulsor reportedly had ingested debris from K-211 that left it noisier than usual during certain performance regimes. She was the oldest operational vessel in the Royal Navy when she was finally decommissioned in 2010. Currently, Sceptre is in long-term storage, as the Royal Navy has been unable to pay for the defueling of a single decommissioned submarine since 2004.

According to Ballentyne, “To this day the Ministry of Defence will not admit the truth.” Questioned by an MP, a minister “skillfully evaded confirming or denying there had been a collision involving the Sceptre, or for that matter, any other British submarine.”

 In fact, such collisions are far from isolated incidents. Aside from numerous collisions with commercial traffic, there have been other scarier run-ins between nuclear-powered submarines, such as two incidents involving Russian and U.S. Navy submarines in the early 1990s, and the collision of French Triomphant and British HMS Vanguard in 2009.

Today, submariners continue to stalk each other deep in the oceanic depths, tracking and studying potential foes, thereby practicing the skills they would use in times of war. It’s a dangerous mission—and most navies prefer to keep any of the mishaps that inevitably occur as far as the public eye as possible.

Sébastien Roblin holds a master’s degree in conflict resolution from Georgetown University and served as a university instructor for the Peace Corps in China. He has also worked in education, editing and refugee resettlement in France and the United States. He currently writes on security and military history for War Is Boring.

This article first appeared in July 2019.

Image: Wikimedia Commons