Today we are used to the idea that the best way to counter a submarine is another submarine.
Quiet, sleek and lethal, the attack sub hunts its opposite number using acoustic hydrophones and sonar, stalking one another before dispatching them with torpedoes.
But this is a modern idea, surely? When one looks at the cluttered designs of the First and Second World Wars, these are not the streamlined killers of today.
From when the first modern submarines took to the seas at the end of the 19th century until the end of World War 2, these craft were designed to spend most of their time on the surface, even being designed to attack their targets primarily with guns.
Submarines were intended to submerge only when faced with threat, saving their precious stores of lethal torpedoes for dangerous and defended targets. They were actually more like surface ships with the ability to submerge; hit-and-hide raiders designed to be the scourge of merchantmen.
This told in their performance specifications. Until the commissioning of the famous Type-XXI U-boats in 1944, all submarines had been designed to spend most of their time on the surface. They were faster there than submerged, and the German’s were given credit for creating the true fighting submarine, a vessel designed to perform best underwater.
Except they didn’t.
Meet the R-class.
Commissioned in 1918 these submarines were the first to be built that had an emphasis on underwater performance.
With a streamlined hull, clean lines and large battery capacity for their size, the R-’s were faster underwater than on the surface.
But that wasn’t what was the most remarkable thing about them. The R-‘s weren’t designed to hunt merchantmen on the surface with their guns; indeed, they didn’t even have guns.
They were designed to hunt and kill submarines.
Ordered in December 1917, the R-Class were one of a raft of measures designed to try to combat the scourge of U-boat attacks on British shipping.
For many people, when the concept of unrestricted submarine warfare is bought up they think of the Second World War. The Battle of the Atlantic and the US submarine campaign against Japan tend to get a lot of attention for the crucial parts they played.
But it’s easy to forget that in 1917, the German Kreigsmarine unleashed their U-boats in a campaign that came within a hair of knocking the British out of the First World War.
So bad were things that at one point the UK only had six weeks of wheat left to feed the population; a margin far too close for comfort.
Desperate for a counter, the British explored a range of measures to counter the U-Boat menace. Amongst these was the idea of using submarines to attack the U-boats when on the surface.
The problem was that whenever a submarine detected a threat they would, naturally, submerge.
One design, the L-class, mounted it’s 4-inch gun in the conning tower, the idea being that on detecting a submarine the crew could surface and rapidly engage it. But this was recognised as a rather poor measure.
The R-class got round this by being true underwater hunters. Capable of 14 to 15 knts under water, they were the fastest submarines built until 1938.
Small subs at 410 tons on the surface, they were fitted with two large electric motors for their size that could generate 1200 horse power that was delivered to one shaft in a design scheme that still looks modern today.
But as true predators the R-‘s didn’t just rely on their higher speed. The class was fitted with a 25hp “creeping” motor that would allow them sneak up on unwary targets quietly – another feature that is absolutely critical in modern submarines.
They were also the first Royal Navy subs commissioned with six bow torpedoes. Unlike other submarines of their time they had 18-inch torpedoes, not the then standard 21-inch weapons.
This allowed for the fitting of the six tubes, plus the ability to carry more reloads, as it was recognised that their prey didn’t need the heavy hit of a big torpedo to sink them.
The intention behind the R-class was that they could hunt U-boats that were surfaced and, using their ability to creep and/or dash, close in so as to ensure a kill with their bigger spread of lighter torpedoes.
But what if the U-boat became aware of the lurking submarine and submerged? This occurred several times during the war, leading to the somewhat comical event of both submarines sailing around observing each other’s periscope before finally giving up and slipping away.
Submarines at this time were being fitted with hydrophones – hence the need for the R-‘s creeping motor – but these served as general detection instruments on most submarines. They were used for basic awareness when not on the surface or at periscope depth.
But the R-class was the first class to mount multiple hydrophones with the intention of providing target data on a submerged target.
Five hydrophones were mounted in the bow section, allowing some gauging of target position. Should a U-boat submerge, they would not be safe from a spread of torpedoes from one of the R-‘s.
And this was in 1918!
Unfortunately, timing is everything. Though they correctly predicted the ultimate form and function the submarine would take, the R-class were both too early in conception and too late in their fielding.
Only getting into service in the last months before the end of the war, the R-‘s saw hardly any service, though one may have launched an unsuccessful attack on a U-boat just before the armistice.
They therefore never got the chance to prove their design philosophy.
Also, their revolutionary design meant they were unpleasant ships to handle. Submarines were still effectively in their infancy and underwater handling was only just beginning to be explored. It would be some decades before this was resolved.
Ten were built, but their specialist nature meant that there was no role for them in the post-war navy and all but two were scrapped. The survivors, R-10 and R-4, survived for a few more years serving as underwater targets for anti-submarine warfare training.
So ended the R-class submarines – a great example of the right idea at the wrong time.
Ed Nash has spent years traveling around the world. Between June 2015 and July 2016 he volunteered with the Kurdish YPG in its battle against ISIS in Syria; his book on his experiences, Desert Sniper, was published in the UK by Little, Brown in September 2018.