- In 1900, Babcock & Wilcox licenses a number of patents relating to burning pulverised coal fuel from the Atlas Cement Company. These remove the need for a coal fired boiler to have a grate while increasing the rate at which coal can be burned, allowing for a more efficient water-tube boiler design with fewer stokers.
- Then in 1902 HMS Challenger is launched at Chatham, the first ship in the world to use pulverized coal in her boilers. Her sister ship, HMS Encounter, will use Dürr type boilers with conventional stoking. It is rapidly noticed that Challenger produces far less smoke than Encounter at speed.
- In 1903 the four Topaze class protected cruisers are ordered with Babcock & Wilcox pulverized fuel boilers. HMS Amethyst is the first to be laid down, and will also be the first warship larger than a destroyer to be fitted with Parsons turbines rather than triple-expansion engines.
- HMS St Vincent is laid down in 1907 as the first battleship with both Parsons turbines and pulverised fuel boilers. The design is the result of a stand-up row between Jackie Fisher, Sir Philip Watts and Sir William May about the proper role of battlecruisers in a fleet action and should be able to sustain 25 knots while maintaining the same armour and armament as the preceding Bellerophon class battleships (the speed capability being treated as most secret). While it will in fact only be able to sustain 24 knots on trials in 1911, the contemporary Indefatigable class battlecruisers only have a knot on the design while carrying two fewer guns and half the armour.
- With the very satisfactory design of the St Vincent starting to change a few minds at the Admiralty about the value of Battlecruisers (including to the surprise of many Jackie Fisher), the 1909-10 naval programme is to be 8 fast battleships of the Orion class. These will have four twin 13.5" turrets and will be able to sustain 25 knots.
- After the 1910-11 and 1911-12 naval programmes produce what are essentially repeats of the successful Orion class with minor improvements, the 1912-13 programme will go for an enlarged version with 15" guns which forms the Queen Elizabeth class.
- The 1913-14 programme is essentially a repeat class of ships but using oil rather than coal fuel in the form of the Revenge class. While not offering any more power than a pulverized fuel burner, oil is significantly easier to handle and it has been noted that after long periods of time at high speed in coal-fired ships the bunker trimmers tend to be unable to keep up with the demands of the boilers leading to an enforced reduction in speed.
Pulverised Fuel (one-shot)
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You will have a problem with the pulverized coal onboard. You need to keep it in a whole form until just before you use it in the boilers. If you don't you run the risk of a coal dust explosion onboard the ship, even with waiting till the end stage if you don't have a way for good dust suppression you would still run the risk. In combat you have to make sure you would be able to have some kind of water spray in case of an emergency.
This will have major effects on the development of the Imperial German Navy, which was far more dependent on coal than the Royal Navy.
The patents are held by B&W in the US, and there's nothing to stop Germany from licensing them.
The patents are held by B&W in the US, and there's nothing to stop Germany from licensing them.
It's a cross between the two classes really: these Orion types have the 8 x 13.5" armament of the Lion class rather than 10 as OTL. This in combination with much better boilers is enough to get it up to speeds which are regarded as battlecruiser ones for anybody except Fisher at the time while keeping their armour. I'm handwaving things a bit to get this past Fisher, essentially by letting him have 8 not-quite battlecruisers to play with.
Very much so. Essentially it's a 13.5" version of the Queen Elizabeth class made possible by the improved boilers.
I'm assuming that there is a dedicated ball mill in each engine room, and that any coal powder created is immediately burned. The whole place will end up covered in coal dust, but no worse than any other ship of the time. Trains experimenting with pulverised fuel seem to have been loaded with the stuff, but that's most likely down to a limitation with the loading gauge rather than anything else. Remember that the RN needs any pulverised fuel ships to share a fuel supply with the rest of the fleet, which means lump coal.
Fuel supply is still going to be an issue (in OTL any extended action would slow down as the ready-use coal was used up and it had to be manhandled from deep bunkers). The real benefit here is that pulverised fuel has a much larger surface area to volume ratio than lump coal, and doesn't need a grate to burn in. This means that you avoid the grate limit (i.e. the air flow rate at which lumps of coal are blown out of the chimney!) and just like oil burners can increase the amount of heat generated in a particular size of boiler, with consequent increases in the power rating of that boiler. The RN were doing something similar in OTL by spraying oil onto the coal, this does the same but more effectively.
Yes. If anybody has the head-space to write such a timeline I'd be fascinated to read it. I've essentially stopped here because it's going to get very complex very fast.
Uh... not exactly. The initial patents were filed in 1899 and 1900 in OTL, but nobody picked up on them outside the cement industry (which is what they were invented for) until the 1920s or so. Here, someone at B&W makes the link earlier and with the naval races going on in Europe thinks there might be some mileage in it.
Now the US aren't interested really - they've got lots of oil which gives the same benefits, and without an immediate threat they're taking an evolutionary path. That isn't true in the UK where Jackie Fisher is very much a revolutionary by nature and oil supply is a concern. B&W also have a UK subsidiary (set up in Glasgow in 1881, with all their international business run from London since 1891) so my assumption is that the engineering work needed to turn the patent into an actual boiler would be done in the UK rather than the US. That means that while the Patent information is available, much of the rest they need to know is not and this would slow down German adoption.
What I had in mind here is that there are a LOT of experiments with different boiler types going on at the time (this is when the world was converting from fire-tube to water-tube) and everything up to the Topaze class would be lost in the noise of such experiments. A really alert German naval intelligence service might pick something up with the Topaze class, but it would probably be pretty murky to them as to whether it's a major benefit or not. St Vincent is where the Germans will absolutely realise what is going on, but at that point they essentially have to start developing the technology from the patent and scale it up to battleship level. That's going to be very tough - and it really isn't retrofittable - so the König class are probably a bit early and if the Baden class get it then it's too late to make any real difference.
If the Grand Fleet can do 24-25knots sustained vs 21knots of OTL that could make a big difference at Jutland or whatever the big fleet battle ends up being.
I think the lack of the 'Splendid Cats' is also an advantage, it means the Battlecruiser Force from OTL doesn't exist as the capital ships have the same top speed. Overall I think the benefit of Beatty on a tight leash and the fleet training and fighting together outweights the loss of the 'fast wing'.
I was thinking more about the effects on the Imperial Japanese Navy not being dependent on oil. It won't affect WWI but WWII is a different matter.
Off topic question, pulverised fuel would seem to give better conditions for the fireman but would it improve on efficiency and general operations for coal fired steam engines?
muddyleathers
Banned
Interesting thought about the Japanese. Would this system work with their low quality coal?
It's been pretty much universally used for coal fired power stations for getting on for a century now, mostly because it's much easier to operate than previous systems such as chain-grate loading. Efficiency is a bit more difficult to address since it's mostly tied to the metallurgy of the boiler tubes and hence the pressures and temperatures you can run at, but it will tend to burn a bit cleaner which will help.
If you're thinking of locomotive steam engines, it's been tried but really isn't beneficial enough to be worthwhile. The added complexity is a major handicap in an environment where low capital cost is a major issue and they've already got highly developed and very cost-effective Stevenson-type locomotives in mass service.
The bigger the system the more compelling the advantages: RN battleships of the time tended to use 18 boilers while the Lion class had 42 boilers of very similar size. My understanding (although I don't have any sources for it) is that the boiler size is driven by the size of grate which can be manually fired. With mechanical firing - and indeed the use of pulverised fuel which is blown in as essentially a very large flame - it is likely that this sizing limit can be relaxed somewhat.
< diagram taken from https://www.navalgazing.net/Engineering-Part-2 >
Essentially the pulverised fuel burner would be fitted where the furnace door is at the moment, blowing horizontally towards the back of the furnace. That allows for a higher burn rate (the grate limit being eliminated implying more power from the same boiler volume) as well as enabling the furnace to be practically scaled up a bit which should be more weight-effective. Essentially you're going to get more power from the same weight and volume than you would from conventionally fired boilers.
However, oil gives you the same benefits plus eliminating the need for men to move coal about (roughly half the engine room manpower), increased energy density in the fuel, etc. It's still coming, but I think there's a window of opportunity where everyone is still committed to coal and this technology is just about mature enough for adoption.
Depends exactly what is wrong with the coal, but should be OK. The coal dust burns in the air which means you don't have issues with clinker formation in the grate blocking up inlet air, although you do need to make sure that the ash cools enough before it hits the boiler tubes or you'll have problems with them getting glazed up and killing the heat transfer from gas to steam.