The Podcast of the Lotus Eaters - PREVIEW： Epochs #241 ｜ The History of the Steam Engine - Part II

00:00:00.000 Epochs!

00:00:20.340 Hello and welcome back to Epochs. Today we're going to talk again all about the history of

00:00:26.300 steam and steam engines and all things related to that and i am joined by alex how are you sir

00:00:30.800 hello good afternoon yes yeah i'm very looking forward to this because last time you was on

00:00:34.640 yeah we only really scratched the surface didn't we we um yes we went off on uh on quite a tangent

00:00:41.460 we talked about all the earlier stuff things like um just the very very earliest concepts of a steam

00:00:47.160 cylinder and newcomer and a little bit of james watt didn't we so in other words the very very

00:00:52.740 first kernels of the thing you could even a push call a steam engine yes so today we're going to

00:01:00.500 try and get a bit more into it and a bit more of a bit more of the history yeah we're going to

00:01:04.100 actually get into it because we went off on a massive tangent about what would you do if you

00:01:07.740 had a million slaves in in ancient greece and could you could you build a steam powered battle trireme

00:01:13.020 which i enjoyed immensely but it didn't quite fit the brief so the thing i had in mind was how do

00:01:17.580 we go from sort of a newcomer pump pumping water out of a cornish mine to 120 mile per hour flying

00:01:27.720 scotsman in like the 1930s yeah 1920s 1930s yeah like how the history of that the story of that yeah

00:01:36.220 it's it's really good to say yeah it's the cornish um because it it really does come down to a cornishman

00:01:42.500 richard trevithic who is the inspiration for trevithic day in cambourne which is well worth

00:01:47.820 the visit if only once just to see what cambourne's like uh but uh cornwall obviously has a great

00:01:54.600 history of mining and mining under the sea go back to the ancient times i mean even the the ancient

00:02:01.360 greeks um used to in the bronze age were getting their tin from cornwall um so there's a long history

00:02:08.280 of it but mining under the sea water's a very pressing issue so obviously they're quite early

00:02:13.960 adopters of of uh atmospheric engines but the thing with that which is the newcom which is the

00:02:19.640 newcom and engine uh but they are extremely inefficient yeah very low pressure right very

00:02:25.000 low pressure you just can't pump much water very far with it with the best within the world you just

00:02:29.100 can't yeah and the the sizes the other thing with a very low pressure engine is if you want large

00:02:34.940 powers out of it it has to be enormous right because your only vacuum it is limited by air

00:02:40.540 pressure so it's about 14.7 pounds a square inch and if you're going to build a massive one that costs

00:02:46.440 uh well too much money it's just not economical yeah yeah so they don't or they never did well

00:02:52.320 they did build some but yeah you know the absolute ludicrous ones but eventually you just end up having

00:02:58.220 to build two because it's easier to build two than build one massive one right um you you end up at the

00:03:03.180 sort of upper limit of the technology but the other thing about the inefficiency is that you've got to

00:03:06.440 have the coal and there's no coal in cornwall right so there was a tremendous problem of the coal for

00:03:13.820 the engines came from south wales because that was their local supply so it's not a million miles away

00:03:19.420 but it's an annoying it's far enough yeah yeah right um and obviously is that why just just put something

00:03:25.420 together in my head why in newcastle they could do it yeah because in for a while i think the two main

00:03:31.260 places where they were using um engine cylinders to pump out water was cornwall and newcastle yeah

00:03:37.920 but of course that in newcastle they're using it to pump out a coal mine so you just bring the coal up

00:03:42.900 and chuck it in the in the pump and then whatever's left you sell on whereas the mine captains actually

00:03:49.180 have to buy it in and you start getting to the limits of the infrastructure because there were you

00:03:55.260 know legends of like thousand horse cart traffic jams on the mud tracks between like new lynn and

00:04:02.240 penzance and truro and around here you need an enormous amount of coal relatively enormous amount

00:04:07.500 of coal if you're burning sort of the the little one they've got at the moment apparently burns 10

00:04:13.000 tons a day well that means 12 that means 10 horse carts a day of coal might take two days to get

00:04:20.340 there so you need 20 on the road right you know before in the late 17th century or sorry late 18th

00:04:27.320 century early 19th century there would be dozens or hundreds of these in cornwall right yeah so

00:04:32.040 right there it's just a silly amount of coal you need yeah right so the the impetus is there to make

00:04:38.040 it more efficient and uh richard trevithick who his schoolmaster said is a bit of a loafer uh not good

00:04:45.140 inattentive and all the rest of it um has a natural knack an ability with mechanical systems

00:04:53.120 he quite quite quickly um becomes a mine captain as they call it who's a sort of general manager

00:04:59.400 slash supervisor chap um and starts to play around with concepts and what he comes up with is is the

00:05:06.360 concept of what he calls it strong steam whereas now we call it high pressure steam and even then we're

00:05:11.920 talking sort of 25 50 pound a square inch so now that to me sounds a lot yeah in the scheme of

00:05:19.680 things though is it in the scheme of things no it's about you convert it back into atmospheres and it's

00:05:25.400 about two or three atmospheres so two or three times atmospheric pressure okay um but that in of

00:05:33.320 itself so you put that much more you know two or three times atmospheric pressure into the engine

00:05:41.040 it means the engine can be a half or a third the size of a of an atmospheric engine to get the

00:05:48.500 equivalent power out of it the problem you get them with high pressure steam is that it's really

00:05:55.520 quite dangerous all right the thing can blow up it can blow up yeah and you can't the boilers that

00:06:00.540 were using at the day that were called a haystack boiler or a box boiler was essentially a a box

00:06:06.480 over a fire so you've got massive flat surfaces and the moment you try and put a pressure in it they

00:06:12.440 try and balloon it out like a barrel yeah so what trevidic comes up with is the initially he comes up

00:06:19.420 with the cornish boiler um which is a big tube full of water with a little tube in it with fire in it

00:06:26.260 so once you've got a round shape it naturally self-supports so it's much much more um strong

00:06:33.600 and it's much more economical with the material as well it's just it's a better shape and the two m

00:06:38.400 plates um you then essentially make them quite thick and then put sort of girders across the back

00:06:45.000 of them and a couple of tie rods at each end to hold the two flat surfaces in line i was gonna say

00:06:51.740 because one of the one of the uh it's not really the right word to say but like one of the problems

00:06:58.640 with that would be um that it needs to be engineered well enough and the materials need to be strong

00:07:04.080 enough yeah but when you're dealing with trying to make a business and make a profit yeah then people

00:07:10.260 are always going to try and do it for the cheapest way possible right yeah and so in theory it's all well

00:07:15.540 good but then people made ones that still just blew up yes yeah right and the metallurgy wasn't there

00:07:22.640 at that time and the ability to quality control wasn't there as well so you can't do

00:07:29.160 like proper materials analysis you can't take samples away to be tested in any meaningful way they

00:07:35.560 you use a local iron founder who has a reputation for having making decent iron and that's it that's

00:07:42.040 all you've got to go on yeah it's his reputation and then his plate goes off to your boilersmith who

00:07:48.480 also has developed a reputation for not blowing up uh which is quite useful you're just relying on

00:07:54.320 that you're just relying on that it's like yeah this guy's built 100 boilers and none of them are

00:07:58.460 blown up so he must be doing something correct um he also has to develop if you're working at

00:08:04.320 pressures you know how to develop a safety valve so that the boiler runs up to that pressure and then no

00:08:10.560 further right um so he develops counterweight safeties um as well which is literally just a

00:08:17.220 uh a valve on the top of the boiler with a bar across it and a weight on the end and then by

00:08:23.800 adjusting where the weight is you adjust the pressure on the valve and at that pressure it

00:08:27.820 just lifts off and that lets out the excess steam um one of the things i say about that though that like

00:08:33.540 we just say that in passing but like this is the first people ever to do this yeah like you've had

00:08:40.540 all sorts of empires throughout the the millennia yeah and no one's ever done any of this no no it's

00:08:46.940 all english one gang well if we just design that and do that then that works yeah and they're the

00:08:51.420 first guys to do it ever they're always running up against the limitations i know in our previous one

00:08:56.720 we were talking about um hammers and being able to hammer um we were talking about prop shafts at the

00:09:04.140 time but in boiler plate so a cornish boiler is about six or seven feet across by about 30 feet long

00:09:11.340 so you've got to you got to roll the plate to make the band but they couldn't roll a plate that was

00:09:19.500 about at that time it was about 18 inches wide by about three feet long massive so it's you know

00:09:26.760 that's that's big for the time and that's it's a difficult process to roll the place a piece of

00:09:31.600 plate to a thickness with any degree of accuracy at that time and then because you've got lots of

00:09:37.780 plates you've got lots of joints and joints are failure points and all the rivets that hold the

00:09:43.780 joints together have got to be closed by hand because you haven't invented a pneumatic rivet gun

00:09:48.040 so you've got you know dodgy plate being held together with possibly dodgy rivets that have

00:09:56.980 been driven in by hand by a guy who's probably drunk um so there's all these things but some of

00:10:04.040 them actually managed to do a good enough job that the confidence gets there and they actually um

00:10:09.720 actually managed to move forward the on the on the on the other side of it so once you've made your

00:10:15.800 steam the other thing he does is he comes up with uh yeah they come up with uh a principle called the

00:10:23.920 cornish principle which is a slight improvement on the watt engine but still using atmospheric

00:10:29.920 um principles there's a lovely lovely video which for some reason is on the shell is in the oil

00:10:36.100 company's youtube channel and it was made in 1948 about cornish pumping engines and they do those

00:10:42.960 classic like black and white um cartoony diagrams about how things work it's absolutely lovely but

00:10:49.100 essentially you've still got the same problem where your pump rod's gone down which means your pistons

00:10:53.560 come up how do you get it back down again and what they did was they actually you close the top of the

00:10:59.980 cylinder you put your high pressure steam in the top which then pushes it down yes shut the inlet valve

00:11:07.240 and then they have a pipe that goes from the top of the cylinder to the bottom and you open that and

00:11:13.680 the weight of the beam transfers the steam from the top of it down into the bottom so now you've got the

00:11:20.740 full cylinder on the bottom all right then you open it out to the condenser it sucks it back down

00:11:25.600 right once that's going you've then got 25 pound of steam on the top and a vacuum on the bottom

00:11:33.380 and that boost gives you much more power out of the out of the engine so the cornish start again no

00:11:42.260 one's ever done that before no and it's such a simple it is elegant isn't it it's such an elegant

00:11:47.140 way of doing it and and but it's still relatively low relatively low pressures low pressures and

00:11:53.640 not fast no so in the flying scotsman you've got the thing going yeah this is going you they've got right

00:12:01.620 slow as shit right yeah they've got absolutely beautiful ways of on the pumping engines they

00:12:05.640 can actually adjust both the length of the stroke and the stroke rate right and it's all it is is the 0.98

00:12:10.980 operating rods that operate the valves go down into into the basement under the cylinder and they've

00:12:16.760 got it's almost like a car damper so as it goes up it draws water into a into a little cylinder and

00:12:23.640 then there's a tap on the side and as the bob comes back down again by adjusting how open the tap is

00:12:29.940 you can adjust how quickly it comes back down again so if you open it all the way the thing

00:12:34.460 will go like the clappers and if you just have it dribbling it'll just slowly slowly slowly come

00:12:38.660 down and then it will repeat and that was again an economy thing because you only want to pump the

00:12:44.240 water out that is actually there you don't want it over pumping yes i think it's important to point

00:12:50.040 out at this stage because we're still talking about what the late 18th century yeah 1790s into about

00:12:56.240 185 yeah so things nearly all things are still handmade right basically yes handmade every

00:13:05.460 handmade every every little thing yeah so it's like every everyone is like a bespoke unique yeah

00:13:13.820 project almost yeah and these these big engines you know we said about how they'd um we'd managed to

00:13:20.760 sort of link them up to spinning mills cotton mills the weaving power loom hasn't been invented yet i

00:13:29.260 think it's about 1820 that's invented so we can mass manufacture cotton cotton uh string we can hook

00:13:40.220 them up to bellows so we can make we can keep the brass furnaces going so we can make lots of cast iron

00:13:46.460 but it comes back to the bottleneck principle so you you've suddenly you can you can mine a lot more

00:13:52.820 coal you can make a lot more thread you haven't developed a steam hammer so that limits the size

00:13:58.180 of the thing you haven't developed a rolling mill so you can't roll big bits of plate yet you haven't

00:14:03.120 all these things start backing up which then means the price of iron and coal have collapsed which then

00:14:09.860 means people have got the spare money to develop things to use all the spare iron and coal for

00:14:15.260 um trevidic actually he uh he constantly gets hounded by bolton watts lawyers uh and the story goes

00:14:27.660 well he they claimed that he was infringing on their patent because of his their bolton and watt patent

00:14:34.180 run out in 1801 so before then you know you've nicked my principle of a beam engine or you know strong

00:14:43.080 steam is the the classic sort of hate campaign that he deserves hanging for his use of strong steam

00:14:49.140 because it endangers the public and all the rest of it all right very much like edison and uh tesla

00:14:54.220 you know a hundred years later like when edison and the other yeah yeah sounds like that trevidic

00:15:00.820 apparently one of these bailiffs came down to try and uh extract royalties out of him and um trevidic was a

00:15:07.540 six foot six cornish wrestler the giant for the time and um he just uh grabbed the guy by his

00:15:14.720 ankles and hang him over a over a mine shaft and sort of shook him shook him out and sent him on

00:15:19.020 his merry way um so yeah he wasn't he wasn't one for the authorities um but he he takes this

00:15:26.060 the concept of high pressure steam and he's like well if i forgot high pressure steam

00:15:30.280 the engine for a given power output can get smaller and smaller so there must come a point

00:15:36.960 where it's small enough and powerful enough to drive itself right you put it on some sort of platform

00:15:43.920 put it on some sort of platform and and away you go and what he comes up with was the puffing devil

00:15:49.840 in 1801 and there is a um replica of it built by the trevidic society it sort of runs up and down

00:15:57.160 campbell neil every year um it was at uh stythians rally this year actually fascinating little thing

00:16:02.140 because there's so many little problems he had to work out um to make an engine unit because nobody

00:16:12.880 had ever built a unit before you had your boiler was in one building and then there was a whacking

00:16:17.540 great pipe that went through the wall and then a beam engine sat in another building it was over three

00:16:21.760 stories so you know you had all the control gubbins in the in the in the basement and then the

00:16:26.800 cylinder on the first floor and then you had the um beam up the top in the roof so how do you how do

00:16:34.920 you make some of that onto something you can even put in a cart chassis um and what he does is he he

00:16:42.860 makes a boiler he then puts a return flue in it um just to try and increase the heating uh space

00:16:50.260 he puts the cylinder in the boiler to keep it nice and toasty so that's that and then he

00:16:56.940 has a vertical beam at the top a cross beam and then just some coupling rods down to the wheels

00:17:03.020 and then it sort of they turn an axle that the wheels sit on and then you can put pins in and

00:17:10.680 then that actually engages the conrod into the wheels and then along you go all right uh some sort

00:17:16.300 tiller steering arrangement um just to point on rails no this is a road vehicle blimey this is a road

00:17:24.200 vehicle yeah uh and uh that's where the the old cornish song about going up cambourne hill coming

00:17:31.020 down comes from all right uh i think it was christmas eve 19 uh 1801 him and his mates you know they've

00:17:38.620 just they've just built this thing and they uh they go for a drive up cambourne hill to the to the pub

00:17:44.960 at the top as you do thoroughly impressed with the with the engine's performance as it roared up the

00:17:53.420 hill they all decamped to the pub and leave it in a barn get drunk have a roast goose completely forget

00:18:00.880 about the engine all the boiler all the water boils away and apparently it uh it then uh blew up and set

00:18:09.160 part of the building it was in oh so yes oh dear oh dear they haven't haven't quite got the concept

00:18:14.440 of no once you put a fire in it you kind of have to stick around it that was the one thing i was

00:18:18.640 going to say it all sounds well and good but isn't it even like modern i say modern even like mid 20th

00:18:23.780 century steam engines right is it not the case that um let's say like a 1920s 1930s or the flying

00:18:30.940 scotsman say you have to keep the fire burning the whole time because if it goes out and the thing

00:18:34.960 gets cold it's dead yeah until you re-fire it again and of course once you've you've put a fire

00:18:40.900 in it and it is hot it does have you do have to keep an eye on it yeah well yeah um you can't well

00:18:47.780 you can just you know leave them if you if you've got it you know ram full of water and it's 100 pound

00:18:52.060 down or whatever it is and the fire's dying you can you can leave it it's pretty safe but yeah you

00:18:56.900 come back and it's cold and you've effectively got to start again and isn't it also like you know uh any

00:19:02.420 rocket engine like solid fuel rocket or anything like that you light it or you get it going rather

00:19:09.040 one way or another and that's it you're then a passenger till the fuel's burnt isn't it not is

00:19:14.160 there an endless like not exactly that in any way but an element of that that once it's hot and it's

00:19:18.880 going you could put the fire out if you want by i don't know throwing cold water on it or something

00:19:23.260 but assuming you don't do that it's going and yeah it's going to keep going the the thing i always

00:19:29.480 say about steam steam engines like steady state right once yeah once they're up to temperature

00:19:34.440 they want to go right um and actually i was i was driving one of the engines back from uh a christmas

00:19:40.680 thing this this on sunday and you can feel it in the engines you know you'll you'll get them up to

00:19:45.960 temperature and she'll i don't know how that roller she must be part mountain goat or something but 1.00

00:19:50.460 she was going up a hill and you could hear you know chuffing away really really enjoying it and you get

00:19:55.240 over you get over the top of the hill and the fire's really hot and all the water you've got's

00:20:00.080 really hot and then the safety valve starts screaming off because you're you're just making

00:20:04.600 steam she's like no no i want to go i want to go i want to go it's like no actually i've got to go

00:20:07.740 back down the other side you fill them back full of cold water and you've sort of got to start again

00:20:11.540 again there's a thing just a slight aside before we carry on with the narrative there's a thing a lot

00:20:16.180 of people say about steam people actually really work on them like you do

00:20:20.820 and really genuinely make them work and make them go um that it feels like it's something that's

00:20:28.500 alive oh they are yeah that it's really alive and you're keeping it alive with how you're tinkering

00:20:34.480 with it as you go along yeah they do and actually i've read um scientific analysis on um steam engines

00:20:44.140 and the best comment that was in the introduction they said they were like frustratingly biological

00:20:49.200 which is a wonderful way of saying that yeah they are because particularly a solid fired solid fuel

00:20:58.560 fired engine when you're getting down into the really nitty gritty tech you know really trying

00:21:05.580 to measure of course in an experiment you're trying to replicate the results

00:21:08.700 and with a steam engine fired on coal no two bits of coal are exactly the same size

00:21:16.820 right the air pressure outside is no and the air temperature and the humidity is never going to

00:21:22.180 be quite the same there's never quite the same amount of soot in the tubes or in the firebox

00:21:27.580 so there's you know the the boiler plate is never quite the same temperature and the

00:21:31.900 properties in the water are never quite the same and there's so they they do they've there's a mood 0.92

00:21:38.720 there are if you get bad coal they can be a complete bitch really it's really really bad or for some 1.00

00:21:46.960 reason you haven't fired it quite properly and and the the great clinkers up and then you just can't

00:21:51.640 get them to work and and at a certain point you've just got to admit defeat and start again and i have

00:21:57.360 done it we've had we've had um we had a load from south africa and a third of it was rocks didn't

00:22:05.640 help yeah right um and it was really horrid stuff it didn't it didn't burn like any coal i've ever

00:22:12.000 seen before um very very fine ash it was almost like talcum powder the ash it was very light and it

00:22:19.700 was very very fine but it gummed up the tubes if you left it for any length of time it would just

00:22:26.900 immediately clinker over what's that mean which is clinker is actually molten ash all right and if

00:22:32.780 you've got very high ash content in the in the coal obviously when you're chuffing away you're

00:22:38.920 pulling air through so you get the fire really really really hot and if you then stop you end up

00:22:44.940 with a layer of ash because the fire continued continually burns so you've got a layer of ash over the top

00:22:49.300 but over the top of really hot fire and it fuses into this solid layer of very brittle

00:22:59.040 it does actually look like slag and it's got the sort of mechanical properties of like set plaster

00:23:06.520 okay it feels like that and all that does is of course it chokes the air off right right and then

00:23:14.360 it gets worse because it's poison it's absolutely poison for the fire and it you end up with

00:23:19.240 these little holes where there isn't any clinker and then the fire is trying to pull all the air

00:23:25.300 through that tiny hole which then pulls a hole in your fire which then means there's no coal in that

00:23:30.300 hole which then means you're pulling cold air through all right so that comes back to it being a living

00:23:35.120 thing yeah of but you'll you'll do it the next day and that won't happen right for some reason

00:23:43.040 yeah you'll just you'll fire it in a slightly different way so the thickness of the fire bed

00:23:48.060 will be slightly different and you'll you'll have the you know the lumps will be slightly bigger which

00:23:54.800 means that the the structure of the fire has got some more holes in it which gives the ash somewhere

00:24:00.640 to go so it can go down into the grate or it'll burn slightly slower which so it doesn't get quite as

00:24:07.180 hot but the gas flow is still there so it means it can pull it out over the top things like that

00:24:12.800 so that's why an experienced steam engine driver and engineer yeah it is there is an element of an art

00:24:20.800 to it oh yeah that they see what the coal they're working with know it inside out like looking at the

00:24:28.600 fire all the time checking it all the time all the things you just mentioned and much much more yeah

00:24:33.800 and there's an art to that yes it'll take years to feel and just know intuitively or very quickly at

00:24:40.160 least what's going on and why it's gone wrong in any given way um fascinatingly i mean you know

00:24:44.840 jumping ahead into the sort of big four days the great western and we're sat here in swindon which

00:24:49.880 is the hallowed ground of great western steam that they bought all of their coal from south wales

00:24:57.640 right and south wales coal is soft anthracite so it's it's quite and it is soft i mean you you

00:25:07.100 muck it about too much and it just dissolves into dust so you've got to be very very gentle with it

00:25:12.560 and in fact western locos were always cold by hand they never used mechanical coaling because it just

00:25:17.760 used to pound it up into dust but it's got a very very high carbon content it's about 95 98 percent

00:25:24.640 carbon what that means is that it burns very cleanly but ironically it's actually quite difficult

00:25:31.180 to set on fire okay because what you usually do in coal very much like wood is that as you heat it up

00:25:38.180 the gases in it evaporate off that then forms flames the flames get the carbon hot enough for it to start

00:25:46.100 to decompose into carbon monoxide and then you burn the carbon monoxide into carbon dioxide and that's

00:25:51.020 where most of the heat comes from right so western engines because you were running very very low

00:26:00.100 volatiles in in the in western coal they never had wide fire boxes and you could run a very very deep

00:26:08.180 fire and there's there's a typical western fire and you see in um in the museum here there's like king

00:26:14.100 george of fifth you've got a you've got a fire bed that's 11 and a half feet long from the from the

00:26:20.720 door to the front of the fire box is 11 and a half feet okay it slopes down i think it's about two feet

00:26:27.080 it goes down but it's only four feet wide this is the bit where you see someone with a shovel shoveling

00:26:33.780 into a hole yeah and you you go you have quite a few feet long yeah so you've got to go in with

00:26:40.880 the with the shovel and hoik it so as it goes in through the hole which is only about this big you

00:26:46.660 can put it perfectly on a on a corner 11 and a half feet away but you run a very very thin fire at the

00:26:52.760 front and it comes back and it and it basically comes up to the door so at the back the fire's about

00:26:57.880 this deep right very very deep fire and it almost acts as like a gas gasifier essentially and you can

00:27:05.820 you can run it like that because what western engines were good at because of the way the

00:27:09.960 great western was built was they do very very long runs so moderate power for a long time and then

00:27:16.800 there's a nip where you've got to get up like two miles of one in 80 or something like that and you

00:27:21.340 suddenly put an explosive demand on the engine right but it's only for about 10 minutes or so okay and

00:27:26.980 then you're up over the top of the hill and then you're away again so that's that like the chilton 0.99

00:27:31.540 what hill what the i thought it was extraordinarily flat from london out to bristol london to bristol's

00:27:37.100 all right okay the bristol to exeter run you go up wellington bank okay and i think it's white ball

00:27:43.060 hill and somebody in the comments will correct correct me because it never really won't be sorry

00:27:46.560 but it it goes from flat as you come across the levels the somerset levels then it starts to go up to

00:27:52.660 about one in 150 and then it which is still pretty flat which is quite flat it's that steep for a

00:27:57.940 railway okay and then it and then it peaks at about one in 80 but that's one in 80 in the tunnel

00:28:03.040 right and then you go through the tunnel and then you back down the other side then you just follow

00:28:07.100 the x all the way down to exeter so that that's what it is there's there's like spurts and south

00:28:13.940 wales has got quite a lot of them cornwall's got quite a lot of them um as well where you do that

00:28:19.200 whereas um if you're burning northern coal which is hard coal which has got a much more um volatiles

00:28:27.240 in it the northeastern railways you see the even back to the great northern atlantics and the and

00:28:34.580 the gresley's engines big wide firebox letterbox to try and get everything through but you get with a

00:28:42.160 hard coal you get a much much bigger flame length all right so you need a much a wide box brick arch

00:28:49.680 combustion chamber and they they ran such a thin fire apparently that you could see the coal dancing

00:28:58.020 on the grate as it's pulling it's literally making the one bit yeah and then as it comes up burns away

00:29:05.120 and you end up with a hole you just put the next one in so they're constantly constantly just guys

00:29:10.600 constantly yeah but it's like half a dozen lumps at a time you just go oh it's going and it goes

00:29:16.080 brighter and it does that as it gets thinner the air comes through it faster and faster and faster

00:29:19.900 it gets hotter and hotter and hotter and then and then you've burnt it it's gone okay so you just

00:29:23.260 see these hot spots you go and and then it goes black next one right and then next one and that's

00:29:31.940 that's what you're doing there's a big thing in like the preserve scene now because we've been

00:29:35.340 using soft welsh coal from fozzy frown for years and everybody's got used to it the mine's shut and

00:29:41.080 we suddenly had to look for other coal and everybody's going you know oh this this stuff's rubbish you

00:29:45.380 know i can't do anything with it it's like no it's just different it's just different right and

00:29:49.680 you're gonna have to learn to be an actual proper fireman not fill the box up and then run it on the

00:29:55.660 damper essentially because most people most people wouldn't know any of that no i didn't know any of

00:30:02.120 that hardly any of that anyway yeah there was different that yeah there would be different um 0.93

00:30:07.780 things that if you had to do on different times but i didn't know like the deepness of the coal bed

00:30:13.920 mattered and all that sort of thing and they had to be thicker at the at the far end and all that

00:30:18.840 sort of thing it's fascinating to me yeah and uh one thing before we go back to traumatic and stuff

00:30:25.060 um you're talking about how you put a tremendous strain on the engine having to go up a hill

00:30:31.800 the first thing that popped into my mind was something in bloody india or somewhere where it's 0.74

00:30:39.520 a really steep incline really steep you're going up a mountain you've got a steam engine and you're

00:30:44.040 trying to get it up a mountain so like you would be put absolutely insane amounts of

00:30:50.380 yeah you're asking it to do something massive yes yeah so you end up you end up with these engines

00:30:57.740 that have huge boilers right tiny wheels right so that the the leverage from the cylinders onto the 0.74

00:31:05.300 wheels is is enormous very slow speeds yeah running shorter distances as possible because they're

00:31:13.740 consuming vast amounts of water of water yeah but then because you've got to get it so hot

00:31:19.540 that it's just it's gonna okay okay i get it and you're just using a lot of steam so you need if

00:31:25.880 you're using lots of steam you need lots of water um but and you probably have like two or three

00:31:30.740 coolies in the tender chucking lumps down to the guy who's actually doing the firing right and

00:31:36.520 he'll be doing it just continuously um so yes but anyway going back to see yeah so trevidic has

00:31:44.540 blown up his first end we hope you enjoyed that video and if you did please head over to

00:31:48.240 lotusseaters.com for the full unabridged video

The Podcast of the Lotus Eaters - December 14, 2025

PREVIEW： Epochs #241 ｜ The History of the Steam Engine - Part II

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