Weapons of War – Oberon-class Submarine
This deadly attack submarine and master of stealth was a key player in the Royal Navy’s ‘silent service’ during the Cold War. Words by Felix Rowe.
When we think of the might of the Royal Navy throughout history, perhaps the first images to spring to mind are the iconic flagships and battleships built to impress, dazzle and intimidate. But equally important in modern times have been those vessels designed to operate on the fringes, away from the visible theatres of war; the clandestine operators lurking deep beneath the waves.
Since the 20th century, submarines – the so-called ‘silent service’ – have played a pivotal role in naval warfare. There’s always been something mysteriously alluring about these covert sea creatures, rising from the murky depths of the oceans. Yet their shadiness has brought mistrust too. Even the British Navy’s own First Sea Lord Admiral Sir Arthur Wilson once referred to subs as “underhanded, unfair and damned un-English”!
But the Cold War, perhaps more than any other period in history, was a time when clandestine activity was essential to maintain tactical advantage. Of this era, the Royal Navy’s Oberon-class submarine, which entered service at the turn of the 1960s, was among the most advanced and effective stealth machines in existence.
Birth of the Oberon
The Oberon-class is named after the king of fairies in Germanic folklore, most famously depicted by Shakespeare in A Midsummer Night’s Dream. Known as a mysterious master of deception that reigns over others, it seems rather an apt description.
The Oberon was, in fact, a development of its sister sub and predecessor, the post-war Porpoise-class sub, which it resembled almost identically in physical dimensions. Essentially, the Oberon was the Porpoise 2.0.
The Porpoise-class itself was a diesel-electric boat, developed in the immediate aftermath of World War Two to succeed the Triton class, which had performed valiantly in that conflict. In total, eight were built in the late 1950s. (Note that this classification should not to be confused with the minelaying Grampus-class of the 1930s, occasionally also referred to as Porpoise-class after the prototype ship of that name.)
Like many military developments of the 1950s, the Porpoise was heavily influenced by forebears developed by Nazi Germany, in this case the Type XXI submarine. A product of the Cold War, the Porpoise was particularly adept at surveillance, clandestine and special forces operations. Technical innovations, including better air circulation, enabled it to stay underwater and avoid detection for relatively long periods of time.
In the development of the Oberon, the qualities that made the Porpoise such an attractive proposition were streamlined and accentuated further. The key difference between the two was that the Oberon’s hull was constructed out of an innovative alloy known as ‘QT28’ steel, rather than the ‘UXW’ steel used in the Porpoise (itself a technical innovation of its time). QT28 was not only simpler to produce, but – crucially – it was stronger, allowing the Oberon to dive even deeper and avoid detection. This material also gave it better sound proofing, adding further to its stealth. The Oberon was enhanced with updated technology, including the latest sonar and radar equipment. The sub was famed for its high speed and doggedness underwater, adding to its all-round advantages.
‘Conventional’ Versus Nuclear
Significantly, the Oberon and its predecessor were ‘conventional’ submarines; that is, subs that relied on the customary diesel-electric system to provide power and propulsion. This factor distinguished them from the nuclear submarines, which by the 1950s were already under development – initially by the US and then subsequently the Soviets.
Technologically advanced in many ways, nuclear subs have some clear operational advantages. While by design conventional subs need to surface regularly as well refuel, today’s nuclear counterparts could (in theory) remain under water indefinitely, without ever needing to rise or refuel. Aside from general maintenance, they are only limited by human needs such as fresh food supplies and other perishables, and, of course, daylight.
But nuclear technology has its drawbacks. First, it’s phenomenally (often prohibitively) expensive, hence putting such machines out of the reach of most navies. To date, only six nations have successfully deployed them: the US, Soviet Union/Russia, France, UK, China and India. Secondly, considering that stealth is integral to the very concept of the sub, the need to cool the nuclear reactors can leave a ‘thermal scar’ revealing its location. In the cooling process, heat is dissipated into the water surrounding the sub, which can be detectable through thermal imaging. What’s more, the reactor itself generates a noise that can be picked up on sonar, unlike the silent battery-powered conventional vessels.
“The silent assassin was far stealthier than many of its contemporaries, while still being able to dive to great depths for comparatively long periods of time, making it a fearsome war machine”
This is pivotal to the Oberon’s story. While most conventional subs (the Oberon included) couldn’t hope to compete with their nuclear counterparts in terms of underwater duration, the Oberon had considerable benefits that largely offset the issue. The silent assassin was far stealthier than many of its contemporaries, while still being able to dive to great depths for comparatively long periods of time, making it a fearsome war machine.