A Technological Appendix to Postblogging Technology, March 1954, II: Revisiting the Nuclear Submarine Question

 

The story here is that the United Kingdom is a rich, first world country and a Great Power. It fought the Second World War in alliance with the United States, now a superpower. At the time the metropolitan British Isles had 34% the population of the continental United States, compared with 20% today. It is fashionable to compare and contrast the technological achievements of the two states across a wide range of warmaking capabilities in WWII, and after, and to attempt to draw larger conclusions. It is particularly interesting to ask whether the steady decline in creditable comparisons over this period (or longer ones going back into the Nineteenth Century) is consequence or, perhaps to some extent, cause of the increasing disparity in national power (and, of increasing relevance, population). One such comparison is between the first nuclear submarine launched by the United States, Nautilus, commissioned on 30 September 1954, and the first British nuclear submarine, Dreadnought, commissioned 17 April 1963. 

Sea power is submarine power now

I looked at Dreadnought back in 2021, when the decision to build Nautilus (and the less-celebrated Seawolf) was first publicised. In the interest of pushing back against some of the cross-cultural comparisons referred to in the previous paragraph, I focussed on one of the more celebrated British contributions to American power, the "raft" that isolates the relatively noisy atomic machinery of modern submarines. I discussed developments in steam machinery in the 1950s, and even got into the hydrodynamic experimental submarine, USS Albacore, and its influence on the development of the nuclear submarine. 

What I didn't have was a contemporary view in the form of a leading article in The Engineer explaining what a mid-century British technocrat would deem important research questions needing to be worked out before the nuclear submarine could take the sea as the lynchpin of modern strategic power. So in this short week, I am going to take another dive. 

In my last post on the subject, I compared Dreadnought to WWI's R-class submarines, a premature attack submarine concept. The Engineer takes a similar tack, but compares nuclear submarines to another failed experimental class of the WWI era, the "Ks." This line of thinking isn't unusual. The modern nuclear submarine is the basis of nuclear deterrence for most of the powers that maintain one, and this alone makes the nuclear attack submarine one of the most important weapon systems of the modern era --perhaps the most important one of all if they have an unacknowledged destabilising role. (That is, if they can reliably hunt and kill the SSBNS of some powers.) 

The imaginative flowering of submarine warship concepts which occurred in the first half of the Twentieth Century is therefore a fascinating episode in the history of technology, and here we have The Engineer getting out in front of the trend, but singling out a class with very different lessons to teach us than the R-class.

 The Rs were designed as high speed underwater attack boats, much like the modern SSN, and failed because sensor technology and associated computing was not up to the job of generating attack solutions in 1914--18. Manoeuvre problems were noticed at the time, but it was not until the Albacore generation that it was fully appreciated that new hydrodynamic departures were needed to operate a submarine safely at these speeds, in a way analogous to the contemporary effort to achieve safe and economic flying in the transonic regime. The Engineer does not discuss the challenging mathematical (to include computing) issues involved in generating exact solutions to hydrodynamic equations, but does note that the hydroplanes of the Ks, and perhaps Nautilus, seem to lack authority to keep the submarines on an even keel underwater. In the case of the Ks, which could have surfaced bows while their sterns were below crush depth, this was a punchline about Victorian technological folly. For modern nuclear submarines, it is a continuing issue, as increasing tactical speed implies increased crush depth and an ongoing effort to create stronger hull materials and design very, very strong boats. This is not, however, a point emphasised by The Engineer, even though shipbuilding steel progress will be an important part of the story leading to Dreadnought, and the QT 35 steel developed for Dreadnought is still a commercial-grade steel product used for "slightly higher loaded components" and "more complex forms" with "higher demands on constancy of properties and surface integrity," for example crankshafts and gearbox parts.  

The Ks, in contrast, were designed as submersible torpedo boats, mainly operating on the surface and using their submersible status to keep their silhouettes low while manoeuvring during a decisive naval battle to head off fleeing enemies with massed torpedo attacks aiming to force them to turn back towards pursuing British forces. This implied a high surface speed, and only steam turbines could supply that speed. Leaving aside the many other technical challenges involved in a steam-powered submarine, The Engineer that the residual heat in the boilers made these boats difficult and uncomfortable to operate underwater, and asks for extended trials to establish that this will not be a problem in the nuclear submarines of the future. 

They were also quite large, and here The Engineer questions their ability to operate in the modern active sonar environment. It is unquestionably true that WWII saw the vulnerability of larger submarines cruelly exposed in the Mediterranean and Atlantic, albeit less so in the Pacific. The Admiralty's essays in large fleet boat designs, such as the "Rainbow" class, were not further pursued in part because of heavy losses while the most successful Royal Navy classes were, unexpectedly, the minute U and V-boats originally intended as training vessels. 

Nautilus' 4200t submerged displacement was clearly identified as a weakness arising from its bulky machinery. The announcement that the follow-on Skipjack-class  would be a smaller class with a single reactor of the new S5W design acknowledges this concern. It also adopted the so-called "body of revolution" hull tested in Albacore and other early high-speed submarine experiments. This further impaired crash-dive capability, one of the less-often acknowledged problems of large submarines, probably because it involves a long and complicated discussion of ship stability. (In brief, a diving submarine has theoretically zero stability at neutral buoyancy and is at high risk of capsizing. The larger the dimensions, the more serious the risk.) This risk was discounted because the Skipjack class was seen as primarily an underwater fighter. 

The modern attack submarine is a standoff fighter using passive detection to identify targets and using homing and guided weapons to engage targets. That is, in theory. My impression was that the actual set of examples consists of HMS Conqueror sinking ARA General Belgrano  with a salvo of three Mk 8 torpedoes, the first burner-cycle torpedo, introduced into British service in 1927 right after the lads at Greenock trolled a Japanese delegation with a demonstration of oxygen enrichment, with hilarious consequences. It turns out that INS Khukri was sunk by a wire-guided postwar French torpedo fired by PNS/M Hangor during the Indo-Pakistan War of 1971, and ROKS Cheonan by a more modern torpedo at least capable of acoustic homing or wire control in 2010. Homing torpedoes have been in service since WWII, and the USN's Mk 37 active acoustic homing torpedo was the standard American SSN weapon through the Los Angeles-class, a period spanning the transition from vacuum tube to transistorised electronics. 

The use of of the Mk8*** against the Belgrano would seem to violate The Engineer's implied stricture against using a large and expensive SSN as a glorified submersible, but is understandable in the light of the long development of the Mark 24 Tigerfish, which notoriously lost its anti-surface capability during a tortuous development process underway as The Engineer writes. Tigerfish, although not by a long ways the first wire-guided torpedo, was the first to employ it in a standby role, allowing the submarine to fire it on warning and release it later once a firing solution was achieved. 

The so-called "Ongar Station" torpedo, so-called as the purported end of the line for torpedo development on its projected 1969 service entry date, certainly didn't lack for ambition, originating as an ambitious internal-combustion engine concept before settling for electrical propulsion. The main problem with the control system seems to have been  a tendency to throw the wire prematurely, but Wikipedia gets in some Tory-bashing, noting that the 1959 closure of the Torpedo Experimental Establishment, Greenock, "disrupted the pace of development." It all seems like a bit of a fiasco, especially considering that the Spearfish, effectively the weapon that Greenock envisioned to begin with, succeeded the Tigerfish only 15 years after its unsatisfactory introduction into service in 1977. (Or by an even more damning timeframe, only a decade.) In tepid defence of this delay, at least part of it must have been the result of a doubling of its specified crush depth from 1000 to 2000ft to meet the threat of the titanium-hulled Soviet high speed/deep diving submarines. Fortunately, the Admiralty's entire network of underwater-research installations has now been privatised, so that this sort of thing can never happen again. 

This discussion has so far neglected the wild heat problem on the perhaps not unreasonable grounds that the particulars of submarine nuclear reactors are TOP GODAMN SECRET.  As a practical matter the technology wouldn't work at all without using seawater as a coolant, and once you've got the ocean for a heat sink the wild heat problem is moot. You do have to spend a considerable amount of emf to pump all that water around, but that does not really seem to be a problem with nuclear submarines. One of the virtues of the Dreadnought design was an active sonar of unprecedented power, the Type 2001, after all. 

That concept seems to have been rethought with more alacrity than was shown by the torpedo development programme, the 2001s being hauled out of the Valiants and Churchills in the "late Seventies," probably at the same time that someone clued into infrared spotlights on tanks being a bad idea, and for the same reason. 

The Sixties, everybody! 

In short, The Engineer can relax. These problems are being considered, and a comprehensive solution to all the problems you raise will be in place in less than a generation, and only fifteen years or so after the first British nuclear submarine hits the water.