“Submarines are the first line and
last line of defence for the United Kingdom.
The last line of defence is obviously the strategic ballistic missile submarines with the
Trident D5 [nuclear missiles].
But the first line of defence is intelligence gathering.
And that’s going to places in the world to gather intelligence and assess future capability to make sure that we’re ready to defend against it.”
Of course, there are many countries trying to do the same to Britain.
Finding hostile submarines is a team sport.
He says for the surface fleet, the most important concern is to stay outside an enemy submarine’s torpedo range of “high single digit miles”, adding: “If you’re outside of that you can do whatever you like as a ship.”
But he sounds a note of caution: “If you’re a single frigate against a single submarine, you’re going to be in trouble.
There are no absolutes in war fighting, there are so many variables in the business of anti-submarine warfare, but a singleton frigate against a submarine? It’s advantage to the submarine every time.”
Hunting Russian submarines starts with intelligence gathering.
Through satellite imagery and other sources, the British military would usually know when a
Russian boat has deployed from its home base of Murmansk in the Russian arctic region.
Such knowledge would be highly classified and not shared widely around the Nato alliance.
Underwater sensors located on the seafloor in the “Greenland-Iceland-UK gap” would send a silent alert back to headquarters when a Russian vessel crossed into the high North Atlantic.
Long-range patrol planes, such as the
RAF’s P-8 Poseidon multi-role maritime patrol aircraft, which is equipped with sensors and weapons systems for anti-submarine and surface warfare, would refine the search, perhaps aided by a friendly submarine.
After that, a close-in search would be conducted by frigates using towed-array sonars trailing behind the ship, dipping deep into the ocean to listen for the tell-tale sounds of man-made technology beneath the waves.
The ships would send out “pings”, basically a sound that would hopefully reach an enemy submarine and be reflected back.
“You’re giving away your position but in this case it doesn’t matter,” Sharpe says.
“As long as you’re outside their weapon range you are safe.”
However, “finding
a well-run nuclear submarine on passive only [not emitting any noise] is a game probably only for another well-run submarine, not frigates,” he concedes.
Only when satisfied the Russian vessel had been found would the frigate’s commanding officer launch the on-board Merlin helicopter to locate the submarine and, if ordered, launch a weapon.
In the case of the
Royal Navy helicopters this would be a Sting Ray torpedo with its sophisticated acoustic homing system and 45kg explosive charge, which is powerful enough to punch through the double hulls of modern submarines.
Sound can travel vast distances underwater and a frigate’s variable depth sonar will, in the right conditions, pick up noise from hundreds of miles away.
Exactly how far sound will travel underwater is governed by a number of factors.
Commanders above and below the surface are aided by highly sophisticated systems to construct mental models of the sea, where depth, temperature, salinity and distance from land all combine to form “layers” in the water.
Sonar pings can bounce off these layers in the right conditions, meaning submarines can hide below – potentially close to ships, but utterly unseen.
Submarine captains have to use their judgment to position their boat correctly in the layers to hunt or hide.
Grueling ‘Perisher’ courseRamsey trained
British and American would-be commanding officers on the Royal Navy’s gruelling “Perisher” course.
This unforgiving final hurdle, that tests future submarine commanders in every aspect of their work before they can be appointed, has just a 60 per cent pass rate.
Success or failure is a very human construct, Ramsey says.
“Ego has a huge part to play in this.
You see some captains that have massive egos that push the limits way beyond where they should do.
“We would get into contact with the enemy and start trailing them [but] we need to tell somebody so they can position other forces.
But breaking off to go back up to periscope depth to transmit, to tell somebody, means you lose the tactical advantage immediately.
“I always found that to be the real challenge.
How far do we push this before we pull out and say, ‘right, he’s going in this direction, you need to put other forces in to intercept’?
“
Anti-submarine warfare is by far the biggest game of chess that you could ever participate in.
“I describe it as being in a really dark room where you’ve got a knife, the other guy’s got a knife, you can’t hear him and he can’t hear you, but you’re looking round, hoping, waiting for the person to make the first sound so you can get in there and deal with them.”
Has Ramsey been in contact with Russian submarines? “I’ve been in contact with many submarines in my time,” he replies cryptically.
But being detected by an enemy submarine is “a different game,” he says.
“You’re no longer in tactical control.
You need to work out how you’re going to evade, get out of there, and come back another time.
You don’t know whether they’re going to fire weapons or not.
You don’t know what their rules of engagement are; it’s not like we’ve spoken to them before we started this.
We have no idea what their rules of engagement are, we only know what ours are.
It’s exceptionally tense.”
Sharpe agrees: “Anti-submarine warfare is a complex and confusing business and the captain who can impose order on that the quickest is the one that inevitably ends up winning.”