This is a pretty famous boat these days, HMS R3. It is the best photographed of 10 R-class boats built during WWI, and I see from my hard drive that it has appeared around here before. Designed specifically for high underwater speed as submarine hunter killers, they were fairly unsuccessful due to not being able to actually find their targets. Evaluating the USN's extensive trials of USS Albacore from 1953 to 1960 (but in particular a 1955--56 series), Norman Friedman called attention to another aspect of the R-class's unfortunate performance, their poor underwater handling. He points out, somewhere in The Postwar Naval Revolution, that the R-class were in the range in which simplified fluid dynamics modelling fails, much as is the case with the transonic flight regime in aerodynamics. Just as postwar aerodynamics depended extensively on full-scale models due to the inability to extrapolate from wind tunnel testing, so the Albacore was a good way of getting past the limits of theory to a good hull form for Skipjack and later nuclear submarines.
Whether any of this features in the Admiralty response to WWI-era experience with the R-class, the fact remains that another R-class, R4, was retained in service until 1934 as a high-speed underwater target. The whole idea of a submarine optimised for submerged speed with a "teardrop" hull was no novelty for the postwar Admiralty, is what I'm saying, and it is hard to believe that anyone ever thought that it was.
Unbelievable, but because of the October, 1952 decision to cancel the British nuclear submarine programme, one that I want to hold up to the light and squint at for a bit. Seriously. What's going on?
In the late 1940’s, the Admiralty became interested in the possibilities of an Anti-Submarine escort vessel of some 2,000 tons displacement, to be installed with main machinery of some 30,000 s.h.p. on two shafts. This new requirement for a fast . . .frigate was a direct result of the Korean War. A speed sufficient to deal with modern submarines was required, together with a very long endurance at speeds in the region of 15 knots . . . This latter requirement came about from an analysis of World War II destroyer operations: this revealed that they spent at least 80% of their life at cruising speed or less, and, consequent upon the characteristics of a destroyer’s power / speed curve, this meant that 80% of a ship’s life was spent at less than 20% of the installed power . . . displacement of the new escort vessel had to be restricted to allow the necessary manoeuvrability for anti-submarine work; this, in turn, severely limited the permitted weight of machinery, plus fuel, to give the specified endurance. The Director of Naval Construction had stated that such a ship could only be achieved if the combined weight of propulsion machinery and fuel did not appreciably exceed 660 tons. By comparison with wartime practice this requirement demanded a very substantial advance in machinery weight, space, and efficiency standards. Based on the Dido-Class cruiser machinery of 15,000 s.h.p. per shaft, the reduction in weight would have to be approximately 33%, with a corresponding reduction in space, if the requirements were to be fulfilled. This represented a 25% reduction in the specific weight of the most advanced propulsion machinery then operated by the Royal Navy, that of the Daring-Class, as well as an improved fuel consumption at the lower speeds
The reference to the Didos reminds us
. . .of the cruiser design branch at the Admiralty that spent most of the Fifties trying to build the Minotaur-class cruisers before being abolished to free up staff room for a nuclear submarine design office. True story! The Minotaurs are mainly famous to me for David Brown's use of a comparison of their legend specifications with the USN's Worcester-class to show that British warships really were technically inferior to American at the end of the war, hence British industrial decline etc. The proposed machinery is, as usual, vastly uninteresting to the historians of warship design, but it seems clear that the cruiser boys were going on and on about machinery as they tried to get their new ship approved.
As often the case, the engineering historical approach gets a bit unstuck from the chronology so that the Y-100 is both a late-Forties initiative and a response to the Korean War. Fortunately, at least ship class histories are open record, so that one can nail down some dates, specifically the laying down of HMCS St. Laurent on 24 November 1950. Somewhere in the sources I read a comment to the effect that the first Y-100 plant was delivered on the specified date at Montreal in the fall of 1951, which was imporant because it was before "the St. Lawrence Seaway froze over," which, again, history, guys. Although, to be fair, this might just be some author being imprecise, and it's not like I can be too critical when I can't lay my hands on the reference. So the first Y-100 was available for delivery in the fall of 1951, and was the last non-nuclear new steam machinery plant delivered to the Royal Navy, albeit just as the Engineering Branch was about to launch into the adventure of refitting Victorious and then deciding right in the middle of the process to install a steam catapult.
Over on the HTP side, the Royal Navy took up a German prototype as HMS Meteorite and ordered two British-built trial boats, Explorer and Excalibur under the 1945/6 and 1947/8 Estimates. Hennessy and Jinks find ruminations on the excessive demands that these two would make on British high-test hydrogen peroxide production (6000 of a proposed annual 7700t production), much less a follow-on fleet of twelve boats, which was cancelled in September of 1949, a fairly rare occurrence in the post-Korean panic buildup that suggests serious reservations about the possibilities of HTP in saner offices of the Admiralty. Or maybe it was proposals to substitute liquid oxygen, which distracted those with a taste for the spicier possibilities of near-future technology. Meanwhile, the service at sea was breaking in the snorkel, a boring, barely-day-after-tomorrow technology while developing the sonars that would make the submerged hunter-killer concept viable in the first place, and failing to develop the weapons that would allow submarines to actually do something if they did detect a target. This, of course, duly failing and leading to the era of the nuclear depth charge, Tigerfish, and, finally, Spearfish, with a disastrous HTP torpedo along the way until finally we have a weapon system that allows attack submarines to sneak up on boomers and kill them without warning, which I am sure is very good for MAD diplomacy.first of a series of classes of conventional submarines continuing through the Upholder, now Victoria class, which I mention to establish that the British didn't give up on conventional submarines until 1992 and conveniently point to the culmination of this trend for those unaware of the sad history of the class. Good luck, Australia! Having the postwar conventional submarine programme well begun, it then somehow swung back behind the HTP submarine with the brief-lived "Boreas" class proposal, some of which, per a 1954 rumination, were to be HTP-powered, while others would be conventional.
Having dealt with the Boreas excursion from reality, Hennessy and Jinks swerve back to the nuclear submarine. "In May of 1950, when the British learned that the US intended to build an atomic submarine," which is one way to put it, Clement Attlee understandably minuted the First Lord about what Britain might be up to along those lines. The First Lord replied that it was hush-hush, because in Britain one didn't talk about atomic matters except to repeatedly, broadly hint that a British atom bomb was just around the corner and shine as much light of publicity on GLEEP and BEPO as the subject would bear. This would, of course, prevent the Russians from thinking of an atomic submarine unless they accidentally read an issue of Time. Having finally come to the point where it is necessary to talk about what is going on at Harwell instead of within the submarine branch, the authors then give us a fairly full account of the programme there, which was then aiming to have the first British nuclear submarine at sea in 1959. Given the real limits of the British (and any other country without vast, semi-stranded hydroelectric generation) fissile materials production programme, some advanced planning was needed, so perhaps it is not a complete coincidence that, after all the vicissitudes of the programme, HMS Dreadnought launched in 1960.
What happened next? Hennessy and Jinks have turned up a memo from Sir William Penny to the effect that he didn't think the country wanted to go in for a submarine reactor, and point out that Halwell's preferred gas-cooled reactors were being pushed forward for very good reasons, given that they would be able to produce plutonium, needed for bombs, and electrical power to address the brownouts and "load-shedding" of early-Fifties Britain. Therefore, they suppose, there was not much call for a pressurised-water reactor, necessarily using enriched uranium, and quite possibly very enriched uranium. this overlooks the potential of the seed-in-blanket reactor, then being promoted at Shippingport as a pressurised-water plant that would have an ancillary U233-breeding role. In January of 1952, Harwell confirmed that a gas-cooled reactor would be too large for a submarine and recommended a shift of focus to liquid-metal cooled reactors, which, as we have seen, would have worked. Whether they might have worked as well as pressurised-water plants, so that we are all victims of technological "lock-in," is entirely another matter. In any case, at the Admiralty work went right on with a pressurised-water design. At (136) comes the payoff. At the beginning of 1952, the projected lack of highly enriched uranium was given as a reason to "suspend" the nuclear submarine project and haul the HTP submarine back on the table.
Where it remained until the fall, when it was cancelled, too, and the Admiralty revived the nuclear submarine in the middle of 1953. The authors then go on to say that the Admiralty's section at Harwell was "expanded" in 1954, which leaves me unclear as to whether it went into hibernation during the nuclear winter of 1952/3; probably not.
So, as far as I can tell from the plain text of this source, at this point, that is, "in 1954," a Naval Section under "Captain (E) Harrison Smith" was established at Harwell, and expanded in 1955. I think that someone is confused, but Captain (E) Harrison Smith, apart from being the grandson of an admiral and an aide-de-camp to the Queen in 1958, has, like most Engineering Branch officers, dropped down the memory hole. Of perhaps more relevance, this source agrees with Hennessy and Jinks that "Rolls-Royce was involved from the beginning," while the latter add that Vickers-Armstrong and Foster-Wheeler were also in the picture at this point, which is important at least for dispelling the notion that this was either Rickover's idea or followed from the Rolls-Royce relationship with Westinghouse, the firm behind the American plant that was eventually installed in Dreadnoought, S5W. (Also the last submarine reactor designed by Westinghouse.) By the end of 1956, the Admiralty cell at Harwell had a shore prototype underway at Dounreay, the point in the United Kingdom which is absolutely furthest from doing anyone any harm if an oopsy happened.
At this point the succession of events occurred which eventuated in Dreadnought going to sea with not only an American reactor, which is understandable after the three year delay in laying down a nuclear submarine or building a reactor to start with, but also the American steam machinery. Given that the American plant appears to have been far too loud, and the enormous pride that is taken in the fully "rafted" machinery of Valiant and successor British nuclear submarines, this is a curious thing that happened! It can be justified on the grounds that the British were in a screaming hurry to have their first nuclear submarine in the water, but why exactly they needed a British technology demonstrator when they could borrow Nautilus for fleet trials goes unexplained. After wandering through politics, the rich trove of Rickover stories in circulation in the community and a final excursion into the HTP story as "Exploder" and "Excruciator" made their brief appearance on the world stage, Hennessy and Jinks wander back to a May, 1957 visit to Derby at which , it is suggested, the outlines of the Dreadnought project were worked out in a one-on-one conversation between Ernest Hives and Admiral Rickover in the privacy of the Rolls-Royce chairman's Hillman.
That's not suspicious at all! So, about that special Westinghouse-Rolls Royce relationship. It turns out that it's because Westinghouse licensed the Avon in 1954 in an attempt to recover from the decisive failure of the J40, taking with it an entire generation of Navy fighters. And while that seems bad, to be fair, Allison somehow survived the T38/T40 debacle, so it didn't have to doom the company, and didn't. That was left to a ludicrously Eighties misadventure into financing, far from the silliest thing that the once-electric engineering firm involved itself in from the 1970s on, leaving only the nuclear side to carry on the company's name. The astonishing wreckage scattered behind the pioneering American jet manufacturers is at some variance with Rickover's shrill insistence that private industry just had to be involved in reactor and steam machinery design.
So: As far as I can tell, the broad outline of the British nuclear submarine programme is that its timing lines up with Harwell's programme for the production of fissile, and I would look like a monstrous cynic speaking ill of certain atomic admirals who were pretty clearly on the spectrum if I spelled out what I think were the actual motivations behind Dreadnought. That leaves the question of Valiant's machinery. Was it an independent constraint on the timeline of the British nuclear submarine? No-one's saying, but somehow Rolls-Royce managed to wedge aside the competition, which seems like Rolls-Royce's motivation for being less than transparent here.
So, if there was a line of technological development leading to Valiant''s machinery, and which constrained the timeline of the first all-British nuclear submarine, the obvious place to look is the state of art in machinery in the Royal Navy as we know it. That state of art, as of 1958, still included a steam installation as part of the pride of place of the late-Fifties Engineering Branch, the COSAG installation on the Tribals and Counties.
So what do we know about it? Precious little, because, again, people don't care about the machinery when they could be talking about missiles and guns. Apart from SSS Clutches, all I have from Wikipedia is that Metrovick is credited with the gas turbine installation here, and Graces Guide has the useful information that it was the G6 of 7500hp, a plant that might be in line of succession from the Beryl. For at least HMS Hampshire, Yarrow Engineers "supplied the four Metrovick G6 gas turbines" to John Brown, the prime machinery contractor, broadly suggesting that the steam plant was by Yarrow, and thus perhaps a successor to the Y100.
And, hah! In 1973, the managing director of SSS Clutches, H. A. Clements, couldn't resist sharing some corporate history, uploaded here. It turns out that the design already existed, and was being used in railroad work, when in 1958 the Royal Navy ordered clutches for the Tribals and Counties. This seems awfully late, but was a direct consequence of the problems with the Y100. Instead of proving the SSS Clutch in static trials, the first County was designated as a technology demonstrator, it says here. the timing seems strange (also, the timing is wrong, but maybe Clements means the first Tribal), but wait on a minute. The Counties followed on directly from the "Mk. 3 Korean war emergency 1951 Dido-class cruiser, which, it turns out, was an unbuilt development of the late-war Didos offered as an "alternative" to the Minotaurs. Of course, it wasn't an alternative in the sense that no cruiser, either Minotaur-class or "War Emergency Dido" was actually built, but that doesn't mean that the machinery wasn't on the table, and, as noted above, the cruiser design section at the Admiralty was turned into the nuclear submarine design section in 1957. I'm not 100% sure how "rafting" the machinery driving a propeller shaft is supposed to work, but we are talking about a gearing arrangement that can't possibly be locked. It seems like clutching/declutching would play a role when the shaft flexes with respect to the machinery raft. I'm sure this isn't the only issue that would need to be resolved in rafting a warship's machinery, but this is the line of inquiry I have going.
So. Was Ashanti's steam installation a stealth technology demonstrator for Valiant? Some of the mystery might well be dispelled if I could just follow up on Clements' bibliography. It's not like no-one ever bothered to say who built the machinery of the Tribals and Counties, just thta the cited articles are in the Trans. Mar. Eng., which UBC never bothered to collect. This is, however, what I'm going with, for now.