The Butterfly Effect: A British AAR

[El Pip]

Chapter CLII: The Pressure of Foreign Designs.​

There are three main factors that determine the range of most naval vessel; the efficiency of the engines, how much fuel it carries and how it's turbines have been geared. There are other factors such as the condition of the hull and the quality of the fuel, but generally these can be controlled while the first three are set at the time of design and require a major rebuild of the ship to change. The three main factors were all in tension with other desirable qualities, if you used less displacement for fuel then you had more tonnage for guns and armour for instance, and as the Admiralty considered the question of range and propulsion it became apparent that they had generally sacrificed range in favour of those other qualities. For the Abyssinian War this had worked well, but it was becoming clear that the Far East was a different proposition entirely. The problem was not distance per se, the Admiralty had well developed plans to deploy an entire fleet the 9,000 odd nautical miles from the UK to Singapore, but the adverse geopolitics of the region. To take one of the classics of Far Eastern war planning it was around 1,400 nautical miles from Singapore to Hong Kong and any planning had to assume there wouldn't be any fuel in the city when the relief force arrived, as an un-modernised Queen Elizabeth-class battleship could do about 1,600 nautical miles at full speed before running out of fuel the issue should be obvious. Of course operating at cruising speed improved things, even the worst of the battleships could expect around 5,000 nautical miles of range at most economical cruising speed, the problem was that this was barely 12 knots. While we have seen that the Admiralty had disavowed the cult of speed that did not mean they were happy for the fleet to move around at the speed of a tramp freighter. There was also the matter of the carriers, air operations of the time required carriers to sail into the prevailing winds and maintain a decent speed while doing so, as a consequence even if the main fleet was transiting at cruising speed the carriers would still be burning considerable quantities of fuel. In the rest of the Empire the solution had been a network of bases, over half of the fuel reserves of the Navy were stored at bases outside of the UK in strategic waypoints such as Aden, Trincomalee and indeed Singapore. Once North East of Singapore that was not an option, Hong Kong was very much a lone outpost and recent events had demonstrated the inadvisability of assuming bases in French Indochina to be available, let alone those in the US controlled Philippine Islands. Hindsight would suggest that refuelling at sea was the obvious solution but at this point in time that was still something of a black art in the Royal Navy, the preference very much being for stationary refuelling in secured anchorages, as much due to lack of suitably equipped tankers as anything else. The only remaining choice was to find a less official refuelling point, the Spratly and Paracel Islands both being identified as possible choices that had suitable anchorages, secure enough to allow stationary refuelling and close, but not too close, to the expected areas of operation. Inconveniently the two sets of islands were claimed by France and China, but as neither had done much about their claims the Admiralty decided to just survey the islands and anchorages without telling either party. For the Foreign Office this became just another headache as the lingering Francophile element in the department would have preferred to support the French claim, just to help repair relations, while the Navy was pushing the Chinese claim on the basis that China had the least capacity to interfere (or indeed be aware) of the Royal Navy using the islands.

Speed-Fuel Use curves produced by the Royal Corps of Naval Constructors for a King George V-class battleship and a notional 'Far Eastern' battleship of the same design but with a revised propulsion system. The actual numbers are not particularly important at this point as they depend heavily upon other factors (auxiliary equipment use, if unused boilers are kept lit or cold, etc) it is the difference in the curve shape that is relevant. The standard KGV was optimised for high speed cruising, useful when hunting down commerce raiders or trying to dash through contested seas under hostile skies, the price it paid for this ability was the extra fuel use at normal cruising speeds. In contrast the 'Far Eastern' battleship could cruise faster and further for the same fuel use, ideal for long transits far from friendly bases, but would burn enormous amounts of fuel if asked to travel at high speed. As with so much in naval engineering, and indeed design in general, optimising for one desirable quality almost always comes with a cost elsewhere. Traditionally the Admiralty had always chosen the high speed option, confident that for the North Sea or Mediterranean theatres this was the best choice. For the South China Sea, not to mention the wider Pacific theatre, things appeared to be very different.​

It was into this febrile atmosphere that the Yarrow request to export high pressure boilers arrived. The request itself was easily dismissed, but as Yarrow had doubtless anticipated it did re-start the debate inside the Admiralty about high pressure steam. To grossly oversimplify matters the maximum efficiency of steam propulsion is limited by the difference between the temperature at which steam is raised in the boiler and the temperature at which steam leaves the turbine, the bigger the difference, the higher the maximum possible efficiency. If you increase the temperature of a boiler then, all else being equal, you will also increase the pressure it operates at. High pressure steam has another advantage, namely that it is more space efficient which is often a very different thing from being fuel efficient, in this case it meant you could either generate more power from the same sized plant or shrink the size of the equipment required for the same power. All of this was somewhat theoretical with a great many assumptions that were often difficult to achieve in practice, as a result it was quite easy to build a high pressure propulsion system that was larger and less efficient than a similarly sized low pressure alternative. Indeed the Admiralty had several examples of this in hand, the collection of battered cruisers taken from Italy during the Peace of Valletta had boilers that ran at higher pressures and temperatures than those in Royal Navy warships of the same vintage, yet used more fuel because the inefficiencies in the boiler systems and turbines swamped any gains from higher pressure operation. The result of the study of the Italian ships had fortified the Admiralty in their view that high pressure steam had severe practical issues and just was not worth the effort, so while existing designs were refined and new types of boilers were trialled in at least one destroyer of every new flotilla, no effort was made to increase the pressure of those systems. As a result the Yarrow request had been a nasty shock; the still under construction Tribal¬-class destroyers had standard Admiralty three drum boilers that ran at 300psi/600ºF and Yarrow were proposing to offer the Russian navy a destroyer with plant running at 500psi/700ºF, on the basis of their belief that an actual state of the art plant would be running at 650psi/850ºF or more. The Admiralty had expected that setting a limit on pressure would mean they were no longer on the cutting edge of propulsion technology, but not that they would fall so far behind. It must be said that Yarrow were somewhat over-optimistic in their belief of what state of the art was, based on their belief that power station technology could easily be adapted for naval use. This was not a completely unreasonable belief and would eventually prove to be correct, however the firm had grossly under-estimated the challenges involved in fitting a large and heavy land-based plant inside a ship's hull.

The A-class destroyer HMS Acheron while on service with the ASDIC trials and training base at HMS Osprey near Portland. Laid down in late 1928 the Acheron was an experimental ships, while her sisters had either the standard Yarrow or new Admiralty pattern three-drum boilers the Acheron had experimental Thornycroft boilers that produced steam at 500psi/750ºF. It was hoped this higher temperature operation would translate into a considerable improvement in fuel efficiency, which it duly did as the Acheron used 25% less fuel than the rest of the class. Unfortunately she could not do so reliably, despite regular refits and a far more intensive (and expensive) maintenance regime she was still crippled with constant mechanical problems, the boilers themselves were reliable but the associated piping and high pressure turbines were not. While her speed and operational trials were officially "inconclusive", despite a second set of trials being carried out just before the Abyssinian War to see if regular service had improved matters (it had not), all the follow up destroyer designs would use the Admiralty three-drum boiler and the Admiralty Engineering Laboratory imposed a limit of 400psi/700ºF on future boilers, effectively curtailing future high pressure steam development in the fleet. Withdrawn from regular flotilla service the Acheron became the trials ship for the Type 128 ASDIC set, a task which did not require her to move particularly quickly or be especially reliable.​

Once it was clear the Admiralty had indeed fallen behind the initial response was straightforward enough; the ban on high pressure research was lifted and work started to investigate the proposed Yarrow designs, both the 'export' design and the cutting edge one, as well as look again at the Acheron system to see if modern materials and details could make it reliable. The next step however was less clear, standard practice would be to conclude the investigation and, if promising, specify that one of the destroyers in the next ordered flotilla include a boiler of that design. Realistically that would mean a ship ordered under the 1938/39 Naval Estimates, allowing the usual build and commissioning time and time for trials of the new ship this meant the Admiralty would be reviewing the results sometime in late 1940. By that point it was hoped that most of the new construction agreed by the Defence Requirements Sub-Committee would have either have been built or already laid down, so there would no chance to include the advances in any of the next generation of capital ships. The alternative was the so called Admiral Fisher solution; just build the things in the expectation that any problems would be sorted before the ships were commissioned. There was a strong argument that the current technology was 'good enough', the Abyssinian War had been won and there were enough low-risk incremental developments available that range could be increased without a radical and risky jump in technology, particularly now design was no longer limited by the naval treaties. Conversely bitter experience had shown that it was slow and expensive to upgrade a ships engines and it had also shown that the Cabinet and Treasury expected capital ships to live a long life, so if the Admiralty played safe they would be stuck with the consequences for quite some time, as a result the example of the Revenge-class loomed large over the decision making. In the end therefore the Fisherite solution won out, partly due to concerns over Far Eastern operations, partly due to a recognition that great efficiency and range would also be helpful in hunting down German raiders but mostly because the Admirals worried they would laying down ships that would be obsolete before they even launched. They knew the Italian navy had been working on high pressure steam (unsuccessfully admittedly) and it was likely they had also provided information on that to the Soviets as part of their ongoing co-operation. The USN had very publicly announced it ships would use a new and more powerful form of steam propulsion, combined that with it's termination of all contracts with Parsons and the many contracts issued to General Electric (which had no naval experience, but was pre-eminent in power station engineering) and it was obvious they too were looking at high pressure steam in the same way as Yarrow proposed. Naval Intelligence had correctly identified that Germany was using very high pressure boilers for the Scharnhorst-class battlecruisers, while it was admitted that they had no real firm data on what the Japanese were doing save that it was likely optimised for range given their Pacific ambitions. The sole bright point was that it appeared the French Navy were at least no further forward, though for the Admiralty to be reduced to the level of such a comparison was damning in itself. So from that perspective for much of the Admiralty board it had in fact been no choice at all.

The RMS Queen Elizabeth under construction in John Brown's Yard in Clydebank, Glasgow. While the hull and internal structure had been completed prior to the boilermakers strike her owners, Cunard White Star, had been forced to chose between a long suspension of work or instructing John Brown to adopt welding to finish constructing the upper decks. Given the financing of the ship was dependent on government guarantees the line's chairman, Sir Percy Bates, soon discovered the board had very little choice in the matter; the government was keen to see welding adopted, so Cunard White Star would have to be equally keen if they wished to keep their financing guarantee. The dozen Yarrow boilers deep in the heart of the vessel had also been completed prior to the strike and careful enquiry by the Admiralty Engineering Laboratory had revealed that they were intended to operate at a much higher temperature than those going into the Royal Navy's capital ships. The Trans-Atlantic route was tough on liner machinery, four days of constant near maximum power output to maintain the 30knots speed demanded by the timetable, repeated every week. That the owners and builders of the Queen Mary had selected high pressure steam for such a high profile ship was taken as another sign that the technology had become reliable.​

This decision prompted a flurry of urgent orders to flow down from the Sea Lords to their many subordinates. The naval constructors prioritised rapidly modifying the plans for two of the upcoming J-class destroyers, one to include Yarrow's proposed "export grade" boilers and plant and the other with an updated version of the machinery used in Acheron incorporating modern welding and materials. The lucky ships would be Jupiter (because Yarrow's shipbuilding arm had already won the contract to build it) and Jaguar (because it was planned to be the last to be laid down and so gave the designers the most time to update the old Acheron plans), the two ships would serve as test beds with the knowledge that one would prove to have been built with the 'wrong' boiler. The next priority was to start on-shore testing of the designs in order to decide exactly which sort of high pressure boiler should be used for subsequent ships. It was at this point that a particularly unfortunate issue was noticed by the Admiralty Board, they had two departments looking at marine propulsion and the demarcation between them had not been well done, resulting in both duplication and far more worryingly gaps. The Admiralty Fuel Experimental Station (AFES) at Halsar had done excellent work on optimising the burning of fuel inside boilers, but considered fundamental questions about pressure outside their scope because the rest of the system (turbines, piping, etc) would also have to be improved to cope. Conversely the Admiralty Engineering Laboratory (AEL) in West Drayton had a large team looking at ship propulsion from the point of view of propellers, gearboxes, turbines and so on, but they also considered boiler pressure outside their scope as they believed all matters to do with boilers sat with the AFES. After a meeting between the First Lord Viscount Monsell, the First Sea Lord Admiral Keyes and the heads of the AEL and AFES that was both frank and direct it was agreed that number of senior officers would take up challenging new posts to help spread engineering knowledge to the more distant stations in Africa and the South Atlantic. It was also decided that all surface ship propulsion work from boiler to propeller would be concentrated at one site in Halsar, under the renamed Admiralty Propulsion Research Station while the AEL would focus on it's mechanical and electrical work, along with the diesel-electric propulsion for submarines which was recognised as being very much it's own specialised area. The first priority of the new station was to produce a recommendation on the boiler system from the many options available and to do so by the end of October at the very latest. The deadline was important because while some of the ships allowed under the 1937-38 estimates had been laid down (the Swiftsures and most of the J-class destroyers) much of the programme had not. In the autumn and into the spring of 1938 the Admiralty had planned to lay down another destroyer flotilla (pencilled in as the K-class), some repeat Town-class cruisers, the first batch of Diadem light escort cruisers and two fleet carriers. It was likely some of these ships would have to use the existing Admiralty three drum boilers at the standard pressures just due to limits on time and manufacturing capacity, but for the carriers and ideally most of the cruisers the Sea Lords wanted high pressure installed. The development programme was a chastening experience for the Navy's engineers, forced to lean on the experience of the power station boiler makers at Yarrow and Babcock & Wilcox it soon became apparent it was not just advances in high pressure they had missed. The lack of economisers on the standard Admiralty three drum boiler was greeted with incredulity and a team hurriedly formed to add them to the boilers destined for the rest of the J-class, this simple addition alone improved fuel efficiency by 10% at all speeds. To the relief of the naval engineers it was not all one way traffic, their experience with several more exotic types of boiler, such as the forced circulation La Mont boilers fitted to HMS Ilex, was valuable to industry if only from a 'what not to do' perspective and several of the innovative details of the Admiralty three drum system were much admired and would find their way into power station systems before the end of the decade. In the longer term, after the initial rushed efforts had been completed, the Admiralty moved to put these industrial co-operation efforts on an more official footing and to include the shipbuilding firms as well. While many would grumble about giving up 'trade secrets' it was clear the previous fragmented approach had not worked and a move to the same co-operative approach used for guns and armour plate seemed only logical to the Admiralty. Time would tell if this would be correct.

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Notes:
This one was a bugger of an update that has fought me every single step of the way. Four complete re-writes and thousands of words sitting in my "this will be useful later (hopefully)" file. However in the end there is only so many times something can be re-done before one has to just hit Post and be done with it.

This all started from me wondering why the Royal Navy ships had a reputation for being short legged, if nothing else because many of them weren't. Ark Royal had the same cruising range as Yorktown for instance. The Illustrious-class and the KGVs however, very much were short legged. A large chunk is just not carrying much fuel, a KGV had maybe 60% of the fuel capacity of a North Carolina or South Dakota. Another large part was the gearing as per the pretty graph, the KGV data is indicatively about right and the 'Far East' battleship is actually from a North Carolina, but the principles holds if not the exact numbers. The Admiralty didn't see a role for high speed cruising but did want max endurance for full speed dashing around after raiders or racing in and out of enemy air cover/Straits of Messina/whatever.

That just left boiler efficiency and the words around that are indeed grossly simplified as I felt a long discourse on Carnot's theorem, the Second Law of Thermodynamics and the Ideal Gas Laws would be a bit of distraction as well as easily available on the internet if anyone truly cared. Royal Navy boiler technology inter-war is a funny one, the Acheron trial did kill off high pressure steam research but everything else carried on and so the Admiralty 3 Drum boiler was still a very good design and incredibly reliable. It also makes comparison very hard because you are never really comparing like for like. There were also very different decisions on priorities being made, the Germans went for crazy high pressure because for them fuel saving was absolutely vital, both due to lack of fuel and to give their ships the long range to get out into the Atlantic and stay there for extended periods. In contrast the British were still over-concerned about the treaties, for instance the lack of economisers on the Admiralty boiler (essentially you use the exhaust from the boiler to help heat up the incoming water) was because that wasn't very weight/space efficient, on a destroyer you would add say 100t of weight to your machinery to save 50t of fuel (assuming the same range). Under the Treaty system that was not a good trade and so the Royal Navy did not fit them, by the time even they had thrown off the treaties there was a mania for efficient mass production, so the design was frozen as it was thought that would help get machinery built faster. In Butterfly different pressures, different decisions.

At Sea Refuelling for large ships while abeam (side by side) had a fearsome reputation inter-war, the USN tried it multiple times in exercises and it kept being called of by the supervising officers as 'too dangerous'. They didn't manage to succeed at it until Nimitz personally ran an exercise in late 1939 and just held his nerve about it. Interestingly abeam refuelling for destroyers was basically routine in the USN so it was just fear of the lack of manoeuvrability of larger ships. On the RN side there are some 1932 trials where they came up with exactly the right answer (abeam refuelling, you can refuel multiple ships and you should use more than one fuel hose per ship for speed) but then did bugger all with it, no doubt in part because there was no reason to. As I am trying to have the British make mistakes the RN will not be making that leap quite yet, forcing them to look at other solutions. Such as the OTL plans to just use some reefs that the French and/or Chinese had not claimed properly, at least until the Japanese invaded China and then the IJN did garrison them. Here though they remain the emergency option.

As to the decision, well high pressure steam does work at sea (a few issues about graphitisation and tricky welding aside) but the learning curve is unpleasant, the USN did take the plunge first in OTL (and have done again in Butterfly) and their first high pressure class did use GE land based power station tech, so had a torrid few months during and after commissioning the first ships as there were a lot of detail problems. But after they were sorted then the system worked reliably so I'm assuming a similar thing will happen on the RN side. the J-class test beds will be challenging ships but by the time the big ships are launched it will all be understood. The overlapping research stations is of course OTL but the fix isn't, in part because wartime panics meant something else was always more important.

 

[RustyHunter]

An interesting naval update, especially since I've never seen much discussion on the relation between high pressure boilers and fuel efficiency. It seems the UK is slowly going in the right direction, although they aren't figuring everything out right away (which I appreciate).

 

[Wraith11B]

I've got to say, having gone through a significant portion of the major naval powers' fleets withe a fine tooth comb for my mod (the intent being to have a balance of engineering systems that have actual trade offs of speed/range/weight), and seeing so many of them as having "Yarrow Three-drum boilers" or some other RN version of the same, this makes significant sense to me. Waaaay back in eigth grade, my science teacher taught us the "hack" of the various gas laws using a sheet with "P T V" on the front and "A B C" on the back, with the understanding that by holding a finger in whichever letter one wanted, reading a question and determining which law applied was easy. The relevant case in our example here being as Volume remains constant, if pressure or temperature rises, the other is directly proportional, and thus C-dudes law (on mobile, I never properly memorized the names and I'm not bothered to look it up!).

Amazing that stuck with me after all these years.

 

[TheButterflyComposer]

There are three main factors that determine the range of most naval vessels

How much water is there and what is the draw?

Inconveniently the two sets of islands were claimed by France and China, but as neither had done much about their claims the Admiralty decided to just survey the islands and anchorages without telling either party.

Ah...I'm sure they won't mind. It's hardly the worst breach of sovereignty the RN had undertaken that century.

 

[Cromwell]

Very interesting stuff, good to see it at the top of the page in its rightful spot too!

 

[Killerduck]

I wonder what was thrown out. Generaly I find your style of writing interesting regardless of subject.

Other than that, good for RN.

 

[El Pip]

An interesting naval update, especially since I've never seen much discussion on the relation between high pressure boilers and fuel efficiency. It seems the UK is slowly going in the right direction, although they aren't figuring everything out right away (which I appreciate).

I suppose because in OTL range/fuel efficiency was mostly only relevant in the Pacific and in reality wasn't really a massive factor. The USN was so good at refuelling at sea they probably could have coped regardless, though it would have caused problems and given their logistics people regular headaches. In contrast the IJN was so short of fuel that even a 25% of more increase in their fuel efficiency was not going to help, by the end they were reduced to just pouring unrefined Borneo crude oil into their boilers, which worked after a fashion but the sulphur content was slowly eating the metalwork from the inside out. The Allies were kind enough to sink all their ships before it became a serious issue though.

I am glad the policy of trying to make mistake and not take every opportunity is appreciated.

I've got to say, having gone through a significant portion of the major naval powers' fleets withe a fine tooth comb for my mod (the intent being to have a balance of engineering systems that have actual trade offs of speed/range/weight), and seeing so many of them as having "Yarrow Three-drum boilers" or some other RN version of the same, this makes significant sense to me.

I too had seen it everywhere and figured it must be quite good for everyone to use it, so I decided to find out why.

Waaaay back in eigth grade, my science teacher taught us the "hack" of the various gas laws using a sheet with "P T V" on the front and "A B C" on the back, with the understanding that by holding a finger in whichever letter one wanted, reading a question and determining which law applied was easy. The relevant case in our example here being as Volume remains constant, if pressure or temperature rises, the other is directly proportional, and thus C-dudes law (on mobile, I never properly memorized the names and I'm not bothered to look it up!).

Amazing that stuck with me after all these years.

It is incredible the things that stick with you and the impact a good teacher can have. That said I'm assuming he was a good science teacher, but maybe he wasn't. I had a teacher who taught us an mnemonic for the order of resistor colour bands, something it turns out I did not need for the exam, have never needed since but can still remember to this day. But aside from that one moment he was rubbish at teaching.

How much water is there and what is the draw?

No those are important factors for whether your ship floats or not.

Ah...I'm sure they won't mind. It's hardly the worst breach of sovereignty the RN had undertaken that century.

Indeed.

Very interesting stuff, good to see it at the top of the page in its rightful spot too!

It is good to see traditions maintained and that an update that was a bugger to write has been well received.

I wonder what was thrown out. Generaly I find your style of writing interesting regardless of subject.

One chunk was on the Italian 'reparation fleet', long discussion on what had happened to it and was planned for it. The first chunk had been "RN find out the Italian cruisers have better engines, panic at falling behind the Italians of all people, so rush to go high pressure". But of course that didn't work when I found out that Italian ships were in fact less fuel efficient due to other mistakes, hence it got cut down a lot. The rest about what will happen to them will possibly emerge later, there are tension in the government about what to do with them.

Another attempt started with an overview on RN build priorities - which bit of the guns-armour-speed triad is most important. Look back to Fishers speed madness and the engines in Hood which were the highest pressure and best in any warship when launched. Then it was a 'due to budget cuts this stopped as R&D was concentrated on ASDIC, fire controls, armour chemistry, etc'. But again it turned out that was not true, most of the post-WW1 destroyer flotillas had a least one 'experimental' ship with a mad boiler in it and the Admiralty 3 drum was a late 1920s design and was constantly being developed and improved until it became a very reliable and efficient design that was much copied. So the RN did keep up research into boilers and propulsion despite no longer worshipping the cult of speed, their mistake was to limit high pressure steam work after the Acheron trials. I feel that Fisher would have just demanded they push on and make it work, though probably at the cost of cancelling all the armour R&D which may not have been a good trade. In any event that no longer fitted and needed redoing.

So those were the thrown out bits. And as always I am pleased that the writing style is meeting with approval.

Other than that, good for RN.

That is the most important thing in any British AAR.

 

[TheButterflyComposer]

No those are important factors for whether your ship floats or not.

Well...whether it floats or not seems critical to how far it shall go?

One chunk was on the Italian 'reparation fleet', long discussion on what had happened to it and was planned for it. The first chunk had been "RN find out the Italian cruisers have better engines, panic at falling behind the Italians of all people, so rush to go high pressure". But of course that didn't work when I found out that Italian ships were in fact less fuel efficient due to other mistakes, hence it got cut down a lot. The rest about what will happen to them will possibly emerge later, there are tension in the government about what to do with them.

From what I recall the revised/og alarm seems to be about torpedoes, and various electronic countermeasures found in the bowels of the ship, kept fairly vague to avoid this sort of problem?

Mind you, there is interest in the british thinking the Italian engines were better, getting worried and a few week later realising they were actually worse.

 

[El Pip]

Well...whether it floats or not seems critical to how far it shall go?

No it's critical to whether it goes at all. Which is a different thing.

From what I recall the revised/og alarm seems to be about torpedoes, and various electronic countermeasures found in the bowels of the ship, kept fairly vague to avoid this sort of problem?

Mind you, there is interest in the british thinking the Italian engines were better, getting worried and a few week later realising they were actually worse.

Fairly sure it wasn't torpedoes as they weren't anything special, definitely not any electronic countermeasures (didn't exist on Italian ships even late war). The engines are in some ways better, they did run at a higher pressure, but were in some ways worse (awful turbines, dodgy gearbox) and the bad outweighed the good so overall they were worse.

Main concern is just keeping them going, there is a cost in keeping them in a useable state and the Admiralty can't see the point. They'd much rather use them as gunnery targets, gives them a chance to try out new guns and shells and gett some more data on how modern ships armour behaves. Others have plans for the ships however.

 

[Le Jones]

The problem was not distance per se, the Admiralty had well developed plans to deploy an entire fleet the 9,000 odd nautical miles from the UK to Singapore, but the adverse geopolitics of the region. To take one of the classics of Far Eastern war planning it was around 1,400 nautical miles from Singapore to Hong Kong and any planning had to assume there wouldn't be any fuel in the city when the relief force arrived, as an un-modernised Queen Elizabeth-class battleship could do about 1,600 nautical miles at full speed before running out of fuel the issue should be obvious.​

I commend this passage, it's not really the getting there, it's making the fleet (of whatever composition) sustainable in theatre. While you are commendably 'taking the rough with the smooth' the fact that this is being considered is a good thing. For a start, if you had to do as the BPF did, and launch a fleet from the UK (and with Singapore compromised, invested, or even fallen) this understanding, at this stage, will hopefully help with the politicians.

Of course it's not just fuel, it's also stores. Has your Admiralty done the study, after the Abyssinian escapade, on 'afloat support'? I seem to remember that this was hugely informative when Admiral Daniel, in '44, worked out that the BPF would need something like 1 million square feet for stores, with another 200,000 or so for air stores. Huuuuuuuge figures. And of course this was in Australia, a long, long way from the front.

This decision prompted a flurry of urgent orders to flow down from the Sea Lords to their many subordinates. The naval constructors prioritised rapidly modifying the plans for two of the upcoming J-class destroyers, one to include Yarrow's proposed "export grade" boilers and plant and the other with an updated version of the machinery used in Acheron incorporating modern welding and materials. The lucky ships would be Jupiter (because Yarrow's shipbuilding arm had already won the contract to build it) and Jaguar (because it was planned to be the last to be laid down and so gave the designers the most time to update the old Acheron plans), the two ships would serve as test beds with the knowledge that one would prove to have been built with the 'wrong' boiler.

I sort of get a Type 45 vibe here, and so long as nothing international explodes while the RN is building and evaluating, you'll probably get away with it. While the power and propulsion issues are well documented (not least amidst the comments in this AAR, I recall) the RN has learnt a lot about electric propulsion.

 

[Davout]

After watching many Drachinifel YT videos, all of this makes sense, although armour and gun size (and therefore weight) would seem to also be factors which would materially affect range too. It is encouraging to see Admiralty getting it right on this occasion.

In OTL, the RN was intentionally designed to operate in comparatively smaller theatres than the Pacific, with a convenient string of stations and access to copious amounts of fuel which obviated the need for long legged vessels. For example, Jesselton (now Kota Kinabalu) was the intermediate refueling station between Singapore and Hong Kong. I can't remember if you have explored this earlier but this strategy also the reason for armoured flight decks and smaller hangars.

On a personal note, I looked back to the start of this majestic opus. The saga began just less than 12 months before my wife died. The slower than real time adventure became my escape through the dark days of single parenthood. Now my daughter has graduated and started the first year of university (studying a Science degree). And I am engaged, again. Thank you El Pip for carrying me on your back through the years to better time. I hope we can meet when I bring my new wife to London next year.

 

[TheButterflyComposer]

In OTL, the RN was intentionally designed to operate in comparatively smaller theatres than the Pacific, with a convenient string of stations and access to copious amounts of fuel which obviated the need for long legged vessels. For example, Jesselton (now Kota Kinabalu) was the intermediate refueling station between Singapore and Hong Kong. I can't remember if you have explored this earlier but this strategy also the reason for armoured flight decks and smaller hangars

I spent a while combing through the early chapters for that balsted Italian super secret thing the navy was so worried about so yes, this time line has the navy sorta quietly begin to abandon the idea of short range ships in small theatres. Ships were becoming so expensive and large, and the Empire was so big at this point, that they seem to have decided they might as well go for long range and hope for the best. I suspect going forward through the 20th century (if the UK and commonwealth sticks together fairly closely, and doesn't collapse and die anticlimatically at the end of this story), that the RN will either have an Atlantic Fleet and a Pacific fleet (just those two) or a generalist worldwide single fleet.

Of course, with nucelar aircraft carriers and nuclear subs being the future, super long range and world spanning ability really has to be the default, so the RN planning for it now is (albeit perhaps unintentionally) a good idea?

On a personal note, I looked back to the start of this majestic opus. The saga began just less than 12 months before my wife died. The slower than real time adventure became my escape through the dark days of single parenthood. Now my daughter has graduated and started the first year of university (studying a Science degree). And I am engaged, again. Thank you El Pip for carrying me on your back through the years to better time. I hope we can meet when I bring my new wife to London next year.

Wow. This AAR is the forums Mount Fuji, isn't it?

 

[roverS3]

So everyone is working together on efficient high pressure boilers, and this Royal navy will end up with more fuel-efficient ships that have longer fast-cruising ranges. An interesting tangent compared to OTL. I'm sure we're now all wondering what those new ship classes are going to look like...

 

[TheButterflyComposer]

So everyone is working together on efficient high pressure boilers, and this Royal navy will end up with more fuel-efficient ships that have longer fast-cruising ranges. An interesting tangent compared to OTL. I'm sure we're now all wondering what those new ship classes are going to look like...

People may feel free to wonder...for the next 5 posts or so.

For me, sounds like a good idea. Especially with oil probably going to fall out of mostly European empire hands in the next decade and into the hands of a mix of the natives, amercian business men and maybe the british.

 

[Wraith11B]

Probably fewer US businessmen, given the predicament that they find themselves in.

Five left.

 

[TheButterflyComposer]

Probably fewer US businessmen, given the predicament that they find themselves in.

Five left.

That's true. Pip seems determined to ruin the American economy for at least the next decade so the British should have the middle east locked down by then...as, to be fair, they should have in OTL had they accepted the Saudi offer...

 

[El Pip]

I commend this passage, it's not really the getting there, it's making the fleet (of whatever composition) sustainable in theatre. While you are commendably 'taking the rough with the smooth' the fact that this is being considered is a good thing. For a start, if you had to do as the BPF did, and launch a fleet from the UK (and with Singapore compromised, invested, or even fallen) this understanding, at this stage, will hopefully help with the politicians.

Of course it's not just fuel, it's also stores. Has your Admiralty done the study, after the Abyssinian escapade, on 'afloat support'? I seem to remember that this was hugely informative when Admiral Daniel, in '44, worked out that the BPF would need something like 1 million square feet for stores, with another 200,000 or so for air stores. Huuuuuuuge figures. And of course this was in Australia, a long, long way from the front.

I am glad it's appreciated, though in keeping with the rough-and-smooth approach things have not reached the level of Admiral Daniels assessments. The Admiralty and the government (or those who think about it) do have a ridiculous amount of faith in Singapore not falling, it was such a shock in OTL just because there had been such faith pre-war.

If nothing else Fortress Singapore was incredibly expensive, one figure that keeps being quoted is £60 million. The Maginot line cost around 6 Billion Francs which was only about £45 million. Admittedly I think the Singapore figure includes all the stores, fuel, plant, equipment and so on (there was at least £2million worth of bunker fuel at the base for starters) so even if you believe the costs this not really comparing like for like, but I think it is still a useful order of magnitude comparison.

I sort of get a Type 45 vibe here, and so long as nothing international explodes while the RN is building and evaluating, you'll probably get away with it. While the power and propulsion issues are well documented (not least amidst the comments in this AAR, I recall) the RN has learnt a lot about electric propulsion.

That was the great luck the USN had, so much of their tech 'came of age' at just the right time, the RN will doubtless hope for the same. At some point the submarine arm may surface into an update and electrics will be further discussed.

After watching many Drachinifel YT videos, all of this makes sense, although armour and gun size (and therefore weight) would seem to also be factors which would materially affect range too. It is encouraging to see Admiralty getting it right on this occasion.

It is indeed a pleasure to see.

In OTL, the RN was intentionally designed to operate in comparatively smaller theatres than the Pacific, with a convenient string of stations and access to copious amounts of fuel which obviated the need for long legged vessels. For example, Jesselton (now Kota Kinabalu) was the intermediate refueling station between Singapore and Hong Kong. I can't remember if you have explored this earlier but this strategy also the reason for armoured flight decks and smaller hangars.

A good point on Jesselton, North Borneo was a refuelling option and it helps cut the distance but it's still a long way across the South China Sea to Hong Kong from there, at least compared to everywhere else the RN fights.

The impact of this on carriers has indeed been discussed and is still under discussion in the Admiralty, how much do they really expect to fight in the Far East and wide open waters of the Pacific? It is a completely different sort of carrier warfare from operations in the Med. Though of course Radar will change that considerably.

On a personal note, I looked back to the start of this majestic opus. The saga began just less than 12 months before my wife died. The slower than real time adventure became my escape through the dark days of single parenthood. Now my daughter has graduated and started the first year of university (studying a Science degree). And I am engaged, again. Thank you El Pip for carrying me on your back through the years to better time. I hope we can meet when I bring my new wife to London next year.

My word. I feel absolutely certain it was your own efforts that did most of the carrying but if I did unwittingly help you through such an experience then I am honoured to have done so. Congratulations on your daughters academic success, her wise choice of degree, your own clearly magnificent parenting and of course your engagement. I would naturally be delighted to meet up in London and hope such a thing can be arranged.

Wow. This AAR is the forums Mount Fuji, isn't it?

Of all the things I have hoped to achieve in this work over the years I never dreamed of anything like this. Quite humbling really.

I spent a while combing through the early chapters for that balsted Italian super secret thing the navy was so worried about so yes, this time line has the navy sorta quietly begin to abandon the idea of short range ships in small theatres. Ships were becoming so expensive and large, and the Empire was so big at this point, that they seem to have decided they might as well go for long range and hope for the best.

A lot of the fleet Fisher built was myopically focused on Germany and fighting in the North Sea, which turned out to be a fairly wise choice but left ships that were all a bit compromised post-war, which was a problem when the Treaty System meant so many had to be kept in service. This is not a mistake they want to make again.

I suspect going forward through the 20th century (if the UK and commonwealth sticks together fairly closely, and doesn't collapse and die anticlimatically at the end of this story),

There are plenty of miserable AARs around where the forces of darkness triumph and all is woe and misery, I have no desire to add to their numbers.

So everyone is working together on efficient high pressure boilers, and this Royal navy will end up with more fuel-efficient ships that have longer fast-cruising ranges. An interesting tangent compared to OTL. I'm sure we're now all wondering what those new ship classes are going to look like...

We will definitely be looking at the result of all this in the future, the relevant chapter notes file has already been started.

People may feel free to wonder...for the next 5 posts or so.

Or we could go for two pages of comments, as once was common in richer and more vibrant times.

For me, sounds like a good idea. Especially with oil probably going to fall out of mostly European empire hands in the next decade and into the hands of a mix of the natives, amercian business men and maybe the british.

As I have said before, your historical determinism is your undoing when it comes to predictions.

Probably fewer US businessmen, given the predicament that they find themselves in.

They have not yet begun to find themselves in a predicament, and that's just with the OTL events to consider.

That's true. Pip seems determined to ruin the American economy for at least the next decade

It's not a deliberate plan, it's just the way the Butterflies flap. Honest.

so the British should have the middle east locked down by then...as, to be fair, they should have in OTL had they accepted the Saudi offer...

Genuinely do wonder what would have happened if the India Office had won that round of the IO vs FO fight over who got to control British Middle East policy. And as I've decided that they have, or at the very least are competing better than OTL, we shall all have a chance to find out.

 

[TheButterflyComposer]

If nothing else Fortress Singapore was incredibly expensive, one figure that keeps being quoted is £60 million. The Maginot line cost around 6 Billion Francs which was only about £45 million. Admittedly I think the Singapore figure includes all the stores, fuel, plant, equipment and so on (there was at least £2million worth of bunker fuel at the base for starters) so even if you believe the costs this not really comparing like for like, but I think it is still a useful order of magnitude comparison

But how many Ark Royals is that???

Also wow...they sure spent a lot on fortress Singapore. Would be a shame if someone just...ran away...wouldn't it?

The impact of this on carriers has indeed been discussed and is still under discussion in the Admiralty, how much do they really expect to fight in the Far East and wide open waters of the Pacific? It is a completely different sort of carrier warfare from operations in the Med. Though of course Radar will change that considerably.

Good point...I suppose the range of the carriers is important but also the range of the planes themselves, esepcially over such vast stretches of open water as the Pacific...

There are plenty of miserable AARs around where the forces of darkness triumph and all is woe and misery

Hey, check out my inkwell guys! I'm two for two on horrifically evil empires taking over Europe and KILLING EVERYONE.

Admittedly the HOI4 one might have had Super Churchill stop me, but he was too busy killing the United States instead.

Or we could go for two pages of comments, as once was common in richer and more vibrant times.

That only used to happen when people spontaneously broke out into song or poetry. Or when I make a flippant comment about something I don't know much about in order to inspire debate and teach me what it actually is.

...

Having said that:

The Welsh.

Discuss.

As I have said before, your historical determinism is your undoing when it comes to predictions.

I tend to qualify with 'probably', because to be honest, the chances of the other European empires not collapsing, the US not starting investing in the wider world again after recovering, and the British continuing to be big oil tyconists for another couple decades at least seems slim.

Genuinely do wonder what would have happened if the India Office had won that round of the IO vs FO fight over who got to control British Middle East policy. And as I've decided that they have, or at the very least are competing better than OTL, we shall all have a chance to find out.

I don't actually know how accurate this is, but I seem to recall from somewhere that a) no one quite knew how much oil (as in, vast, vast amounts) was in Arabia, b) the British were given first dibs on looking and drilling it because of course they were (being the big experienced oil tyconists in the middle east) and c) the british turned it down for some reason or another.

Which is odd, because this would be around the same time, or just after, the british found oil in persia.

 

[nuclearslurpee]

Another weekend and thus another chance to catch up on an AAR, naturally we must choose the one with lengthy paragraphs and...graphs? Well, that's a new one.

There are three main factors that determine the range of most naval vessel; the efficiency of the engines, how much fuel it carries and how it's turbines have been geared.

The fourth factor, the inverse relationship with how well-funded the national Navy is, rarely enters public discussion for obvious reasons.

There are other factors such as the condition of the hull and the quality of the fuel, but generally these can be controlled while the first three are set at the time of design and require a major rebuild of the ship to change.

One might suggest that the first three factors fix the range of ranges.

as the Admiralty considered the question of range and propulsion it became apparent that they had generally sacrificed range in favour of those other qualities.

The Admiralty Plays Aurora 4x

It was into this febrile atmosphere that the Yarrow request to export high pressure boilers arrived. The request itself was easily dismissed, but as Yarrow had doubtless anticipated it did re-start the debate inside the Admiralty about high pressure steam

The Admiralty: "Wait, what's that 'high-pressure boiler' you've got there?"
Yarrow: "What, this old thing? I only manufacture it when I don't care what I wear, darling!"

To grossly oversimplify matters

rabble-rousing from the two-stage turbine crowd intensifies

It must be said that Yarrow were somewhat over-optimistic in their belief of what state of the art was, based on their belief that power station technology could easily be adapted for naval use. This was not a completely unreasonable belief and would eventually prove to be correct, however the firm had grossly under-estimated the challenges involved in fitting a large and heavy land-based plant inside a ship's hull.

Step one is to build a 100,000-ton ship. Step two is a nuclear reactor, but don't tell them that just yet.

The alternative was the so called Admiral Fisher solution; just build the things in the expectation that any problems would be sorted before the ships were commissioned.

The fine print about a ~50% chance that something will go wrong with your bloody ships today can be roundly ignored, for authenticity of course.

it was admitted that they had no real firm data on what the Japanese were doing save that it was likely optimised for range given their Pacific ambitions.

The Japanese doing what is in their best interests? A bold assumption...

The sole bright point was that it appeared the French Navy were at least no further forward, though for the Admiralty to be reduced to the level of such a comparison was damning in itself.

Indeed.

That the owners and builders of the Queen Mary had selected high pressure steam for such a high profile ship was taken as another sign that the technology had become reliable.

This is an optimistic assessment; all it really shows is that at least some owners and builders have deemed thet the technology might be profitable, which is a particularly large difference to account for.

After a meeting between the First Lord Viscount Monsell, the First Sea Lord Admiral Keyes and the heads of the AEL and AFES that was both frank and direct it was agreed that number of senior officers would take up challenging new posts to help spread engineering knowledge to the more distant stations in Africa and the South Atlantic.

This is one way to put it, particularly when the generous Lords involved have taken upon themselves to help the officers involve frame their memoirs in the best possible lights.

While many would grumble about giving up 'trade secrets' it was clear the previous fragmented approach had not worked and a move to the same co-operative approach used for guns and armour plate seemed only logical to the Admiralty. Time would tell if this would be correct.

Of course it will be correct, the UK is the player nation in a Paradox game here and thus cannot possibly screw this up.

This one was a bugger of an update that has fought me every single step of the way. Four complete re-writes and thousands of words sitting in my "this will be useful later (hopefully)" file. However in the end there is only so many times something can be re-done before one has to just hit Post and be done with it.

This is the most relatable sentence of the update.

That just left boiler efficiency and the words around that are indeed grossly simplified as I felt a long discourse on Carnot's theorem, the Second Law of Thermodynamics and the Ideal Gas Laws would be a bit of distraction as well as easily available on the internet if anyone truly cared.

While I always enjoy your work, I must admit continued mystification and some modest amount of continued disappointment at the decisions which go into it.

In Butterfly different pressures, different decisions.

Indeed.

As I am trying to have the British make mistakes

You could try harder.

and thus C-dudes law (on mobile, I never properly memorized the names and I'm not bothered to look it up!).

I think we just call it the Ideal Gas Law around these parts. Though I genuinely can't remember the last time I saw volume used, these days it's all about densities.

The USN was so good at refuelling at sea they probably could have coped regardless, though it would have caused problems and given their logistics people regular headaches.

That is after all what we pay them to have.

I feel that Fisher would have just demanded they push on and make it work, though probably at the cost of cancelling all the armour R&D which may not have been a good trade.

Given how armor has gone since the War, one might consider that he was simply a man ahead of his time.

Well...whether it floats or not seems critical to how far it shall go?

RussianSubmarine.jpeg

Or we could go for two pages of comments, as once was common in richer and more vibrant times.

Indeed.

That only used to happen when people spontaneously broke out into song or poetry. Or when I make a flippant comment about something I don't know much about in order to inspire debate and teach me what it actually is.

...

Having said that:

The Welsh.

Discuss.

I must admit confusion as to why you would want to learn what the Welsh are.

...come on now, reply, you know you want to...

 

[TheButterflyComposer]

The fourth factor, the inverse relationship with how well-funded the national Navy is, rarely enters public discussion for obvious reasons.

Ah yes, can't forget the 4th factor: does the ship actually exist?

This is one way to put it, particularly when the generous Lords involved have taken upon themselves to help the officers involve frame their memoirs in the best possible lights.

Nicer and more generous than living in a dictatorship. When senior command becomes irrelevant or in the way there, they don't pay for their retirement abroad but have them arrested.

While I always enjoy your work, I must admit continued mystification and some modest amount of continued disappointment at the decisions which go into it.

As in, didn't go into enough detail?

I must admit confusion as to why you would want to learn what the Welsh are.

One hears rumours and tall of such things. Considering DLG apparently was 'one of those', we should definitely know more about it. Potentially a grave threat to the empire.