Coal industry - pit, power station and beyond! (types of coal & freight flows)

[Adrian Barr]

When looking into the history of coal trains, it quickly becomes clear that the different types of coal (anthracite, steam/thermal coal, coking coal) and their geographical spread around the UK coalfields had a big influence on rail movements, and resulted in some long-distance flows that would otherwise give the appearance of "taking coals to Newcastle."

Related to this were the requirements of different industrial sectors for different types of coal. There were also a variety of coal facilities beyond the standard colliery / opencast site / power station; from washeries to coking plants and smokeless fuel plants, coal blending facilities, coal concentration depots, coal staithes, coal hoists, a variety of industrial users. This is a general thread for discussion of the "black diamonds" moved by rail.

Growing up in Dorset, the coal industry is not exactly "in my blood" - my knowledge of coal movements before 2000 is mainly from books and the internet, so I'd be interested in hearing from anyone with memories of coal traffic in their local area, or the coal industry in general. Or maybe you have questions, comments, opinions about the underground enigma of coal and its mysterious movements by rail...

I'll start by responding to the comment that got me diving into this internet rabbit hole, discussing coal movements to the coal handling plant (CHP) at Scunthorpe Steelworks:

The type of coal (anthracite) from South Wales was especially good for steel making. Anthracite (as well as South Wales anthracite is found in Canada, Poland, Russia, Ukraine, United States) is the densest and purist even when. Second to anthracite is bituminous coal, but requires turning into coking coal.

Anthracite was historically used for iron-making, but was displaced by coke which is more suitable for modern blast furnaces. As I understand it, compared to the qualities of coke, anthracite is the closest naturally occurring coal (high carbon content, low ash content, hard, low volatile content, low moisture content), but coke is superior in a blast furnace and bituminous coal (of the right type) is better suited for making coke.

A couple of relevant quotes from Wikipedia (you've got to start somewhere):

Anthracite has a history of use in blast furnaces for iron smelting; however, it lacked the pore space of metallurgical coke, which eventually replaced anthracite.

Metallurgical coal is low in ash, moisture, sulfur and phosphorus content, and its rank is usually bituminous. Some grades of anthracite coal are used for sintering, pulverized coal injection, direct blast furnace charge, pelletizing, and in production of ferro-alloys, silicon-manganese, calcium-carbide and silicon-carbide. Metallurgical coal produces strong, low-density coke when it is heated in a low-oxygen environment. On heating, the coal softens, and volatile components evaporate and escape through pores in the mass.

The first answer to this Quora question gives a comprehensive explanation as to why coke is preferred to anthracite in a blast furnace:
https://www.quora.com/Why-is-anthracite-coal-not-used-in-blast-furnaces
The main factors seem to be that coke is more porous (better at allowing gases to circulate), combusts more rapidly, and is less brittle, all of which are critical to the efficient functioning of a modern blast furnace.

Coal (including some anthracite) is used alongside coke in blast furnace operations, for example in pulverized coal injection (PCI), but can only replace a portion of the coke used. This passage from The Last of the Welsh Coal Trains by Chris Davies (2020) suggests that the coal from Cwmbargoed to Port Talbot was used for that purpose:

MSW invested £10 million in a new state-of-the-art processing facility at the washery in 2015 to produce coal suitable for the high-pressure injection furnaces at Port Talbot.

That book has some other interesting snippets of information. Referring to the types of coal found in South Wales:

The coal increases in grade from east to west. Bituminous coal is dominant in the east, higher-grade bituminous (steam coal) is found in the central coalfields and higher-grade anthracite coal generally occurs in the west.

The 'quality' is somewhat relative to the use of the coal, for example Welsh steam coal from the eastern part of South Wales was considered very high quality, and I doubt anthracite would burn well in steam locos. In fact (I should have known) there is a thread on this subject - Anthracite as a locomotive fuel - where the initial post (by 181) points out that "the slow combustion rate requires a large firebox."

Tomos y Tanc: It's a less suitable fuel than steam coal and generally more expensive to mine. In the UK the only anthracite coalfield of any real significance was in the western portion of the south Wales coalfield and it's produce was almost always in short supply and sold at a premium price to steam coal.

Oakdale, which sent coal to Scunthorpe, is way over in the eastern part of South Wales (confusingly known as the western valley). In Railways and Industry in the Western Valley: Newport to Aberbeeg (p103) John Hodge describes Oakdale as "a prolific producer of steam and then coking coal."

Pre-1960s and the opening of Llanwern Steelworks, large volumes of Western Valley sized coal were used to supply GWR and SR engine sheds, the coal being sold unwashed and passing from colliery to Rogerstone Yard for conveyance thence in through trains to destination. With the end of this traffic during the early 1960s, the coal was produced as prime coking coal for supply to the new Llanwern works, and also was used to supply Ebbw Vale, Cardiff Guest Keens and Margam steelworks.

Even within a coalfield, there were no doubt local variations between coal in different seams. For example, take this comment about Onllwyn:

The washery at Onllwyn washes coal from their 3 opencasts,the one above, Selar/Glyn neath and the Tairgwaith operation, so 3 lots of different seams and qualities.
https://www.welshcoalmines.co.uk/forum/read.php?14,43828,page=4

I found a good general explanation of coal types here, summarized in the extracts below: https://www.steelscope.uk/raw-material-coal.php

Coal is classified as either lignite, sub-bituminous, bituminous, or anthracite, where lignite contains the least carbon and anthracite the most.

Bituminous coal is typically divided into three sub-groups - low volatile, medium volatile, and high volatile. Bituminous coal has the required properties to generate steam electric power and is used in manufacturing as well as in coke production.

Anthracite - 90% fixed carbon - burns without smoke (smokeless fuel). Used in domestic and industrial applications.

Fine anthracite / semi-anthracite is used in the steel industry for pulverized coal injection. PCI is a technique developed by the steel industry that involves the injection of coal directly into the blast furnace, improving operational efficiency and replacing some of the coke used in the blast furnace. Traditionally, coals for PCI have been typically high volatile content coals. In recent times, it has been recognized that some anthracite / low volatile coals, previously considered of little value, were suitable for PCI use [due to higher replacement ratio of coke, and being softer and easier to pulverize].

Metallurgical coal, also known as coking coal... is used extensively in steelmaking, and comes in various quality grades, including hard coking coal, semi-hard coking coal, semi-soft coking coal, and pulverized coal for injection (PCI). Compared to thermal coal, which is primarily used for electricity generation, metallurgical coal typically contains higher carbon content, lower ash content, and lower moisture levels.

One of the features of the South Wales coalfield was apparently its "semi-anthritic" (not arthritic) coal. Whilst South Wales produced excellent anthracite and (bituminous) steam coal, this 'semi-anthritic' coal was not ideal for power station use. As Chris Davies explains in The Last of the Welsh Coal Trains:

Aberthaw 'B' burned approximately 5,000-6,000 tonnes of coal a day. It was designed specifically to burn bituminous (steam coal) and the semi-anthritic low-volatile Welsh coal peculiar to the South Wales coalfield, providing a crucial lifeline for the coalfield. It was the only coal-fired power station in the UK designed to burn low- to mid-volatile coal.

This coal was "economically important to the local area but more difficult to burn." This in turn caused problems with EU emissions regulations, and a switch to "high-volatile imported coal" in 2017.

The main use of anthracite is as domestic fuel, since it burns efficiently and the low volatile content makes it naturally smokeless, which is suitable for "smoke control areas" (such as the city of London) where only anthracite, semi-anthracite and low volatile steam coal (or natural gas of course!) can be burnt. This helps explain the use of Welsh anthracite as household coal in London, for example trains to West Drayton Coal depot.

56124 seen at West Drayton in 1997 with HEAs from Coedbach: https://www.flickr.com/photos/actonwellsjunction/54271808880/ (Photo: Ivan Stewart)

Although anthracite isn't an ideal power station fuel, it does have a high calorie (energy) content, and one use of the anthracite 'duff' (fine screenings, as opposed to the larger lumps suitable for house coal) was for blending with lower quality coal, as described in Paul Shannon's Rail Freight Since 1968: Coal

Anthacite was mined mainly at the western end of the south wales coalfield. It was often moved in two stages: first to washeries such as those at Coedbach, Abernant, Gwaun-cae-Gurwen and Onllwyn, then to the final consumer, either in the form of high-quality domestic coal or as "duff" used to increase the calorific content of poorer grades of power station coal.

The anthracite duff could also be used to makes briquettes for use as smokeless fuel, such as those produced at the Coal Products Ltd (CPL) plant at Immingham, which was supplied by train from South Wales for many years. This is a useful summary of CPL's activities taken from evidence to a parliamentary report.

CPL is the European leader in smokeless domestic fuels, based in Sheffield, with 600 employees in the UK. The firm operates over 40 depots across the UK and has manufacturing and sales facilities across the country, as well as in Ireland and South Africa. CPL was founded in 1973 from the non-mining operations of British Coal, and was privatized in 1995 through a management buy-out. Since then it has gone through a period of evolution, encompassing a range of industries from charcoal and activated carbon, to refractory repairs and renewable energy. CPL’s high quality, high performance products have become brand leaders in the market, with well-known names including Homefire, Phurnacite and Ecoal50. CPL’s main manufacturing hub is the modern briquetting plant based in Immingham...

It's interesting to find out these bits and pieces of information about coal that help explain the overall pattern of rail movements. I stumbled across a thread on a Welsh Coal Mines forum [insert joke about the deep web] discussing the mysteries of anthracite. There are some good posts (made more intriguing by not fully understanding all the terms used), such as the one by 'blaen boy' with this comment:

"This anthracite has very low volatile matter just 4.9% , the dry steam has 12.4% ", Little dai said "what does that mean in layman terms", Big dai said "there is more gas and other material in the dry steam than the anthracite and you will get more flames with the dry steam coal "
https://www.welshcoalmines.co.uk/forum/read.php?14,43828,page=4

I love the paradoxical expression "dry steam" which I assume means steam coal with a low moisture content, and the strange discussion about "a clock set in coal" as the ultimate measure of the highest quality anthracite.

The coal from the North/South/West Yorkshire was low grade (probably lignite) and so was preferred to fuel coal-fired power stations.

This is a scandalous accusation against the fine quality of Yorkshire coal! People have disappeared down disused mineshafts for less! (Just kidding)

Below is a quote from a book I'm reading at the moment, Rail Freight - Today by B. Rogers and C.R. Anthony. It's a classic 1989 publication by OPC and a very good book on rail freight which achieves the aim stated in the introduction: "As well as outlining freight movements, we have also tried to put the British Rail operations in context by linking them with the industries they serve." Focusing mainly on the north east of the UK (including Humberside and part of Yorkshire), it's able to go into more detail than an overview of the whole country could. It's also absurdly cheap to obtain second-hand. From the chapter on Speedlink Coal:

Because Yorkshire is especially rich in high-quality bituminous housecoal, there is a heavy flow to Preston in the North West and especially to Scotland.

Healey Mills became a trunk yard specialising in both trainload and wagonload coal. Feeder services arrive from Brodsworth, Grimethorpe Coalite, Kellingley, Markham Main and Monckton, and trunk haulage is to Gartcosh, Hull and Preston via Blackburn.

Being bituminous housecoal, it would be more suitable for use in, say, the west of Scotland (served by the J.G. Russell depot at Gartcosh) than in London (where only smokeless fuel is allowed, as already mentioned).

I'll end this post with a couple of YouTube videos I watched recently, both made by the NCB in the 1970s. The first is focused on mining operations underground, the second on power station coal trains (pay attention to the first - if you got this far into the post, you've been selected to start work down 'pit on Monday!)

National Coal Board 1975 Training Film For New Miners (NCB)

NCB Film Unit - Merry Go Round Trains 1979

 

[Dr Hoo]

Thank you so much for posting the link to the Coal Board’s Merry-go-round film. So pleased that it hasn’t been lost. Remember it well from the early 1980s.

 

[Rescars]

How far do you want to go back? One of the contributory factors to the Quintinshill disaster in 1915 was the distraction caused by the arrival of a train of Welsh coal empties - one train amongst many involved in moving large quantities of high quality steam coal from the pits in South Wales to the British Grand Feet harboured in Scapa Flow.

 

[Magdalia]

A coal consuming industry that you have not mentioned is cement. Near here the Barrington cement works was supplied from Thoresby Colliery in Nottinghamshire for most of the 1960s, 1970s and 1980s. A quick internet search suggests that Northfleet cement works was usually supplied from Welbeck colliery also in Nottinghamshire.

Perhaps you can explain why Nottinghamshire coal is particularly suitable for cement works?

 

[PeterC]

Going slightly off topic, the Eastern and Western Valleys are the two that are focused on Newport rather than Cardiff and were in the historic county of Monmouthshire.

As a boy I used to visit relatives in the Eastern Valley in the 1960s. The mines in the vicinity had already closed, I remember the Varteg "zig-zag" already partially lifted and coal wagons parked under Big Arch. To this day the highway authority only surfaces their half of the roadway under the bridge.

 

[norbitonflyer]

How far do you want to go back? One of the contributory factors to the Quintinshill disaster in 1915 was the distraction caused by the arrival of a train of Welsh coal empties - one train amongst many involved in moving large quantities of high quality steam coal from the pits in South Wales to the British Grand Feet harboured in Scapa Flow.

And the presence of that train of empties in the up loop, and a full coal train in the down loop, was why the down local train had to be shunted on to the up main to allow the overnight down express to overtake it, only to be overlooked when an up troop train was accepted on the same track.

 

[Bevan Price]

Before the Clean Air Acts and Smokeless Zones, huge amounts of domestic (household) coal were conveyed from coal mining areas to cities & towns outside mining areas; some could be fairly local, e.g. Lancashire Coalfield to Liverpool or Manchester; other covered longish distances, e.g. to London from South Wales (mentioned above), The Midlands or Yorkshire. It was conveyed in open wagons - often with wooden bodies, or steel mineral wagons. Almost every town with a railway had sisings devoted to coal traffic - with areas - and probably a weighbridge used by local coal merchants.

Another big use of coal was coal gas production; many gas works were owned by local councils, and many gas works had their own sidings connected to BR & predecessors - many also having their own shunting locos. This ended when natural gas replaced coal gas for (mostly) domestic use. Coke was a by-product of coal gas production. Wagons would be moved to/from nearby goods yards by trip workings.

 

[PeterC]

Another big use of coal was coal gas production; many gas works were owned by local councils, and many gas works had their own sidings connected to BR & predecessors - many also having their own shunting locos. This ended when natural gas replaced coal gas for (mostly) domestic use. Coke was a by-product of coal gas production. Wagons would be moved to/from nearby goods yards by trip workings.

Hemel gasworks were beside the LNWR but were supplied from the Midland Railway branch. When that was closed the sidings were connected to the WCML just in time for the conversion to natural gas. I believe that the connection was never used for a coal delivery.

The MR embankment across Boxmoor was removed apart from one fragment beside what was then the A41. This now looks more like rhe mote of a medieval castle.

 

[6Gman]

Before the Clean Air Acts and Smokeless Zones, huge amounts of domestic (household) coal were conveyed from coal mining areas to cities & towns outside mining areas; some could be fairly local, e.g. Lancashire Coalfield to Liverpool or Manchester; other covered longish distances, e.g. to London from South Wales (mentioned above), The Midlands or Yorkshire. It was conveyed in open wagons - often with wooden bodies, or steel mineral wagons. Almost every town with a railway had sisings devoted to coal traffic - with areas - and probably a weighbridge used by local coal merchants.

Another interesting flow was to Northern Ireland with a significant amount from North Staffordshire to the Mersey ports. At one stage I have a vague recollection of it being semi-containerised.

 

[ChiefPlanner]

"Gas coal" flows could be expansive - the local gas works at St Albans Abbey took in around 80 wagons a day from my researches on the branch at Kew - pretty much 7 days a week via Watford Junction , the withdrawal of passenger servces would have seen the line retained only for that flow , but the passenger service survived and of course the gas works did not !

 

[billh]

Another interesting flow was to Northern Ireland with a significant amount from North Staffordshire to the Mersey ports. At one stage I have a vague recollection of it being semi-containerised.

I recall Cawoods open top twenty foot containers, in a yellow livery , being shipped from Ellesmere Port on the Manchester Ship Canal. Would this be about 30 years ago? There were two container handling machines on the dockside.

 

[ChiefPlanner]

I recall Cawoods open top twenty foot containers, in a yellow livery , being shipped from Ellesmere Port on the Manchester Ship Canal. Would this be about 30 years ago? There were two container handling machines on the dockside.

Freightliner did Nothern Ireland coal "exports" too from Swansea in their own "S" type 20ft boxes - high quality anthracite for domestic fireplaces - via Holyhead (which came back with loose Irish peat for garden centres !)

 

[Adrian Barr]

How far do you want to go back? One of the contributory factors to the Quintinshill disaster in 1915 was the distraction caused by the arrival of a train of Welsh coal empties - one train amongst many involved in moving large quantities of high quality steam coal from the pits in South Wales to the British Grand Feet harboured in Scapa Flow.

For thoroughness, we should go back about 360 million years!

The Carboniferous Period lasted from about 359.2 to 299 million years ago during the late Paleozoic Era. The term "Carboniferous" comes from England, in reference to the rich deposits of coal that occur there.

But seriously, I've enjoyed reading John Hodge's series of books on the South Wales valleys (with a new one out on the Vale of Neath), which go right back to the beginning of the coal and steel industries. The location of the steel industry in places like Ebbw Vale and Dowlais makes more sense when you realise they were originally very close to the sources of the raw materials needed, followed by the focus shifting to export coal traffic, iron ore coming from further afield in the UK and then imported, and so on.

The movement of coal over such a long distance to Scapa Flow is a good example of where a flow doesn't immediately make sense without the context of the quality / type of coal.

A coal consuming industry that you have not mentioned is cement. Near here the Barrington cement works was supplied from Thoresby Colliery in Nottinghamshire for most of the 1960s, 1970s and 1980s. A quick internet search suggests that Northfleet cement works was usually supplied from Welbeck colliery also in Nottinghamshire.

Perhaps you can explain why Nottinghamshire coal is particularly suitable for cement works?

My impression is that the cement industry doesn't need to be too fussy about the coal used, since it's being used directly to heat the kilns, rather than being used as "steam coal" to produce electricity via a boiler, with more specific performance requirements for its combustion. Depending on what type (and cost) of coal was being produced in the Kent coalfield - with coal from Betteshanger being sent north to Scunthorpe for example - almost any movement of coal to North Kent or Cambridgeshire would be over a reasonably long distance.

There's a good website on the cement industry (cementkilns.co.uk) with a detailed page on coal which I'll quote from:

Bituminous coals... are most often used in the cement industry, although steam coals are occasionally used. When burning a pulverised fuel, higher volatiles are preferred because they speed up ignition and allow a coarser grind to be used. Anthracite is too expensive and has insufficient volatiles. Usually, the lowest-priced forms of coal are the finer sizes, and these are most often used, although they tend to have higher free moisture and ash contents. https://www.cementkilns.co.uk/data_coal.html

An answer on Quora details some of the considerations on the coal used for cement production - one comment sums it up by saying cement plants can use low grade coal but need good quality limestone.
https://www.quora.com/What-is-the-u...-industry-Is-low-grade-coal-suitable-for-them

Considering that cement plants have been known to burn tyres, they obviously aren't that fussy! https://www.cemfuels.com/articles/318-tyres-as-an-alternative-fuel

Another big use of coal was coal gas production; many gas works were owned by local councils, and many gas works had their own sidings connected to BR & predecessors - many also having their own shunting locos. This ended when natural gas replaced coal gas for (mostly) domestic use. Coke was a by-product of coal gas production.

I hadn't thought about gas works at all. It wouldn't have occurred to me that coke was a by-product, but it makes sense. Until the coke ovens shut at Scunthorpe and Port Talbot, coke oven gas was used as an energy source on site. The environmental permit for Tata at Port Talbot (large PDF) has a good summary of on-site processes at the beginning, include these paragraphs on coke-making and site energy production:

Port Talbot: Coke Making

Coal is also carefully blended to form a coal mix and layered in coal beds prior to being recovered by a reclaimer and can be blended in silos and taken by conveyor belt to the Morfa coke ovens on site. Here the coal is charged to airtight ovens using a set of four mobile hoppers. Once in the ovens, the coal is heated at a temperature of between 1200 -1300 °C for a period of around 18 hours to produce coke. At the end of the coke cycle, the coke is pushed out of the oven into a rail car and the red hot coke is transported to a quenching tower where it is quenched by water... After quenching the coke is transferred to the blast furnace for use within the iron production process. Gas is driven off from the ovens during the coking cycle and is cooled, cleaned and some by-products are removed. The by-products are collected and either reused or sold. Clean gas is recycled within the site as fuel and excess gas may be vented through a flarestack and ignited.

Port Talbot: Site energy production

The major energy input into the Port Talbot site is in the form of coal which accounts for the majority of all delivered energy. This coal is converted to coke in the coke oven plant and the arising by-product gas (Coke Oven Gas) is distributed throughout the site for use as a fuel. Additional coke is imported. The coke is charged into the blast furnace where it acts as a reductant to produce iron. As a consequence of the ironmaking process vast quantities of low calorific value gas (Blast Furnace Gas) are produced. This gas is fired on the blast furnace stoves, the power station (boilers) and the Coke Ovens. BOS gas is collected from the steelmaking process and used mainly in the Power Station boilers. The above integration of energy producers and consumers enables the maximum use of the site’s own, or indigenous, gases (coke oven gas, blast furnace gas and BOS gas) and minimises the use of purchased premium fuels such as natural gas and heavy fuel oil.
https://naturalresourceswales.gov.uk/media/2467/port-talbot-steelworks-permit.pdf

I recall Cawoods open top twenty foot containers, in a yellow livery , being shipped from Ellesmere Port on the Manchester Ship Canal. Would this be about 30 years ago? There were two container handling machines on the dockside.

Looking at Paul Shannon's Rail Freight Since 1968: Coal, and David Ratcliffe's Private Owner Wagons in Colour, the Cawoods container traffic began in 1986 through Ellesmere Port, shifting to Seaforth in 1992 (with the containers conveying domestic coal for Northern Ireland). Cawoods had 172 PFAs, but as traffic declined 44 were sold to British Gypsum in 1996 and another 60 to British Fuels in the same year. The British Fuels PFAs operated from Gascoigne Wood to Scotland with red containers, with a weekly block train to Mossend that lasted until 2000, and "Enterprise" wagonload movements that ended in 2003. Meanwhile the remaining Cawoods traffic ended in 2004.

1987 - Cawoods Terminal, Ellesmere Port: https://www.flickr.com/photos/penmorfas/53849674293/ (Photo: Dave Sallery)
1992 - Cawoods train in Seaforth Docks with 56130: https://www.flickr.com/photos/8arail/48920192266/ (Photo: Doug Birmingham)

Trains ran from a variety of loading points over the years, Lynemouth and Coedbach being the main ones that spring to mind, although by the end the coal was mainly from the Midlands.

Classic Trans-Pennine action with the Lynemouth flow in 1988: https://www.flickr.com/photos/railcam/52222226051/ (Photo: Keith Sanders)
Undated shot of 37797 on Ellesmere Port - Coedbach empties: https://www.flickr.com/photos/tunnel_one/6010601127/ (Photo: Antony Guppy)
At Tower in 1994: https://www.flickr.com/photos/74165767@N05/49926330757/ (Photo: Driver 59)
From Clipstone in 2000 with 60090: https://www.flickr.com/photos/181919693@N06/50597649568/ (Photo: John Catterson)

 

[matchmaker]

There were also coal slurry fired power stations - in Scotland at Barony in Ayrshire and Methil in Fife. Methil certainly received supplies by rail.

 

[Adrian Barr]

There were also coal slurry fired power stations - in Scotland at Barony in Ayrshire and Methil in Fife.

I'd forgotten about Methil and its box wagons of coal slurry. Some factoids from Wikipedia:

Methil: The power station consisted of two 30-megawatt (MW) generation units for a peak rating of 57 MWe. It was commissioned in 1965 for the then South of Scotland Electricity Board. It was designed to utilise low-grade coal slurry supplied from the washeries of the nearby Fife coalfield.

This station was built as a sister to Barony Power Station on the West Coast of Scotland, in Ayrshire. As the Scottish coalfields were exhausted or abandoned in the mid-1980s, waste accumulated in coal tips, and this waste was used as a fuel in the Methil and Barony power stations. However, as the tips were cleared, operations at the two stations ceased due to lack of coal-slurry fuel and the uneconomical operation of such small facilities.

This station ceased generating in 2000 and was put into standby as a strategic reserve. The power station was finally demolished in 2011

Coal Slurry: Coal-water slurry fuel is a mixture of fine coal particles suspended in water. Such slurries are used to transport coal. Typically, the slurry is dried prior to combustion.

A coal-water slurry fuel is defined by a number of factors including its viscosity, particle size, rate of sedimentation, ignition temperature (800–850 °C), combustion temperature (950–1,150 °C), ash content and calorific value...Ash content of less than ten percent is desirable for boilers.

I'm not sure if Barony was supplied by rail, or just took its coal from the adjacent colliery... appears on Railscot here: https://www.railscot.co.uk/locations/B/Barony_Junction/
Only other photo that comes up is this shunting loco, so it must have had an internal railway at least:
https://www.flickr.com/photos/60854097@N06/31383526476/ (Photo: Pats Trains UK)

37690 leaving Methil: https://www.flickr.com/photos/36034969@N08/10020827075/ (Photo: Adrian Nicholls)
Unconventional power station coal unloading: https://www.flickr.com/photos/peter_todd/7982743820/ (Photo: Woolwinder)

==========================================

Going back to basics and the humble coal yard, this brief British Pathe film from 1958 shows a 16-ton mineral being unloaded through the central door, with the top flap also lowered. A shovel and a bag, what more do you need?

Coal Trucks (1958) | British Pathe

Strange to see a new-looking 16 ton mineral - I looked up B557510 from the film and it was built as part of Lot 2915 in 1957/1958 by Metro Cammell. It's amazing to realise how many of those wagons were built. That "lot" was for 1550 wagons, and it was just one line of small type on two pages listing similar orders. Figures for 1966 show over 250,000 of those 16-ton mineral wagons were built! Coal certainly was king.

For a more advanced method of supply to coal merchants, this cine film of the coal drops at Sowerby Bridge being shunted in 1972 oozes atmosphere (there's another longer video on the same channel titled "Shunter at Sowerby Bridge" with more footage).

Filling Coal Drops at Station Road, Sowerby Bridge 1972 | Channel: David Roy Ball

I found this photo of the coal drops at Sowerby Bridge, which gives a good view of them from the street: https://www.flickr.com/photos/mng3985/32306353982/ (Photo: Martin Gibson)
And a view from between the tracks on the coal drop: https://www.flickr.com/photos/mng3985/31614381944/ (Photo: Martin Gibson)

I suppose the concept of a "coal drop" is self-explanatory, but it's interesting to see what they looked like!

 

[Adrian Barr]

Power Stations

Continuing the "pick & mix" coal theme, this post looks at power station coal and the power stations themselves.

After briefly considering the coal used in cement plants in post #13, I started wondering about the type of coal used in power stations. This can be summed up as "steam coal" - but what makes a good steam coal?

The short answer seems to be "bituminous coals of high volatile content." These have a high calorie content, burn efficiently, and have low ash and moisture content. The calorie content of coal is related to both the carbon content and the volatile content - a higher volatile content means that the coal burns more easily.

After some internet browsing, this is a summary of what I found. Particularly useful was a Quora thread which is linked below under the quote.

It seems that most types of coal can be burnt in a power station, but the design of the power generating equipment needs to take the type of coal into account.

Compared to bituminous steam coals:

• Lower quality sub-bituminous and brown coals have a much lower energy density (higher moisture and ash content) and require larger furnaces of special design to burn the coal efficiently.
• Higher quality anthracite has a higher carbon and calorie content but low volatiles, and requires specially designed firing systems to burn the coal for longer at higher temperatures for efficient combustion. This in turn produces high levels of nitrogen oxides (pollution) which are "very difficult to abate". The slow burning that is an advantage when used as a domestic fuel becomes a disadvantage in a power station.

In addition to efficient combustion, the amount of sulphur dioxide and nitrogen oxides produced are another consideration. The "scrubbers" and flue gas treatments that de-sulphurise and remove nitrogen oxides do not remove 100% of these emissions, so the combustion process itself (related to the type of coal used) is a factor in keeping emissions below acceptable limits. As an example, Aberthaw's problems with emissions control using semi-anthritic South Wales coal were mentioned in my initial post.

The coal burnt in power stations is a compromise between quality, cost and local availability. Lower quality coal can also be "sweetened" through blending to make the overall mix more suitable for power station use. I remember hearing that particular shipments of lower quality coal (cheap imports) would sometimes cause problems during discharge at the power stations, perhaps due to the consistency and moisture content.

This comment on the peculiarities of coal from the Powder River Basin (Wyoming / Montana, USA) is a good illustration of how all these considerations combine:

It is a very low sulfur coal, so you don’t have to scrub sulfur from the boiler exhaust gas. This coal is lower in the heating value range, so it takes more mass, and it’s pretty high in % moisture (Approaching 30% moisture). So, when you pay to transport it, roughly every third rail car is filled with water that you have to work to get rid of. It’s also hard to grind to the fine powder you really want for combustion; it’s kind of gummy, so it’s harder to handle. Sometimes it likes to just catch on fire without being prompted, so you have that worry as well. Many of the boilers in North America were designed and built with higher energy, more easily ground, coal in mind, and the retrofitting and operational changes required to meet sulfur emissions standards have been problematic. (Quora - Jim Kuhn)
https://www.quora.com/What-coal-is-used-as-major-fuel-in-thermal-power-plant-only

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But how does a power station work?

On YouTube I found this excellent 10-minute explanation by a manager at Rugeley Power Station - it provides a clear explanation in straightforward non-technical terms without being overly simplistic. For rail content, there's about 30 seconds showing an overview of the discharge area, starting at 1:28 in the video.

Granville Camsey: Rugeley Power Station | British Library "An Oral History of the Electricity Supply Industry"

One of the comments on that video was that the explanation was good but they would have liked to see more of the power station. This video filmed at Ferrybridge gives a similar explanation of how a power station works, and accompanies a school tour giving some interesting views inside the power station. Very brief appearance of an EWS 66 discharging HTAs at 3:27

Ferrybridge Power Station Educational Documentary

Now for the trains - three great videos showing power station coal being discharged. The first two feature traditional MGR wagons during the 1990s, while the video by Mike Wilcock demonstrates the use of modern bogie hoppers for comparison.

Merry Go Round - trains discharge coal at power station [Ratcliffe 1992] | Editions Audiviseul BEULAH

Class 58 unloading coal at Ironbridge Power Station June 1998 | David Othen

Coal unloading at Aberthaw Power Station with 70809. 21st Aug.2017 | Mike Wilcock. Rails in Wales

 

[LMS 4F]

I recall Cawoods open top twenty foot containers, in a yellow livery , being shipped from Ellesmere Port on the Manchester Ship Canal. Would this be about 30 years ago? There were two container handling machines on the dockside.

I recall Cawoods open top twenty foot containers, in a yellow livery , being shipped from Ellesmere Port on the Manchester Ship Canal. Would this be about 30 years ago? There were two container handling machines on the dockside.

I had recall these going through Wakefield Kirkgate with a 56 on the front and the trains started in the North East and had one of the locos allocated to I believe Blythe.

 

[Adrian Barr]

Ratcliffe Power Station: 1967 - 2024

Below are a couple of interesting videos of Ratcliffe power station when it was still operational. The first is a view of the site by drone. The merry-go-round loop can be seen going around the large coal stockpile in the centre of it. At 0:42 there's a good view of the twin-track coal unloading area, with a separate hopper discharge building to the right for limestone. This was added when the Flue Gas Desulphurisation (FGD) plant was opened in 1993, with brand new National Power class 59s and new bogie wagons delivering limestone from Tunstead.

The limestone was used to absorb sulphur dioxide (associated with acid rain) from the exhaust emissions. Limestone is mainly calcium carbonate, and the chemical reaction with the sulphur dioxide produced calcium sulphite / sulphate. Calcium sulphate is the chemical basis of gypsum, which meant that the resulting by-product of "desulphogypsum" from the FGD plant could be used in plasterboard manufacture in place of natural gypsum.

Most power stations fitted with FGD received limestone by rail and also despatched desulphogypsum by rail, but Ratcliffe is only about 5 miles by road from the British Gypsum plasterboard factory at East Leake (Hotchley Hill) so despatched it by road, and there's another British Gypsum facility at Barrow-Upon-Soar producing plaster which is only about 15 miles away.

One oddity in the video is that is states "According to Uniper, the operator, it runs on hard coal, anthracite." After a bit of delving I found a section of the Uniper website where it refers to Ratcliffe as being a power station running on hard coal. However, Uniper is a German company, where "hard coal" refers to both anthracite and bituminous coal. In this case the phrase "hard coal power station" is a distinction in Germany which means it is burning hard bituminous coal and not soft brown coal (lignite). The reference to anthracite is a red herring - good quality anthracite is very expensive and lower quality anthracite does not combust well in a power station, so it would be an odd choice for Ratcliffe, which was designed to burn local sources of bituminous coal.

Uniper website - history of Ratcliffe Power Station: https://www.uniper.energy/united-kingdom/power-plants-in-the-united-kingdom/ratcliffe-soar

Britain's last coal power - Ratcliffe on Soar power station | Martina looks at things

The second video has some good footage from inside the power station itself, e.g. inside the turbine hall. The "360 view" means it was filmed with a special lens and you can change the camera angle. I watched it on my living room TV and the sheer scale of the place comes across very well.

UNIPER RATCLIFFE POWER STATION 360 VIDEO TOUR. Full authorised tour of UK's last coal power station.

Also worth remembering is that Ratcliffe had a completely separate loop (accessed from the south) for the loading of fly ash. Until 1991 this was despatched in CSA presflo wagons to Fletton, where it was used to fill in old brick pits (I think water was added to turn it into a slurry which could be pumped around the site).

58009 skirts around the lagoon at Fletton in 1985: https://www.flickr.com/photos/d1015/6862529997/ (Photo: Paul Townsend)
58015 at the unloading facility at Fletton: https://www.flickr.com/photos/32755955@N05/4393436298/ (Photo: Mickoo737)
58005 departing Peterborough with empties for Ratcliffe in 1985: https://www.flickr.com/photos/tunnel_one/49723726742/ (Photo: Anthony Guppy)

I mentioned in another thread that Railscene filmed a cab ride in a class 58 from Bentinck to Ratcliffe in January 1987. Railscene cab rides were normally released as full-length videos, with 15 minutes of edited highlights being included in their regular Railscene "video magazine." The Bentinck video was never released in its entirety (too short to be a standalone release), but it does appear on DVD as an edited 15 minute version in Railscene 10, with the same footage also being included as the first section of Cab Ride Highlights No.1.

A typical MGR train of 36 wagons might have conveyed 1100 tons or so. Ratcliffe was a 2000MW power station with four generating "units" of 500MW each. These could be switched on or off independently of each other, depending on the amount of power the grid required. I remember that when all four units were operating (for example at peak demand in the middle of winter), the power station could handle roughly one train an hour, with all the coal going straight into the power station for combustion. At other times, if two units were operating for example, some of the coal might be sent to the stockpile instead and discharge could take longer.

The narration in that cab ride video mentions that at the time of filming in January 1987, Ratcliffe was receiving around 20,000 tons of coal a day, with Bentinck and Cotgrave each supplying 30-35K tons a week. Bentinck despatched up to 5 trains a day, with the opencast disposal point at Bennerley (which is passed in the video) despatching 2 per day. Other pits mentioned as supplying Ratcliffe are Calverton, Sherwood, Sutton, plus "Shirebrook area" pits.

For comparison, a 1994 sample MGR programme for Ratcliffe in Paul Shannon's Rail Freight Since 1968: Coal has arrivals from Thoresby, Welbeck, Bilsthorpe, Calverton, Nadins, Denby, and Asfordby. Of those, Thoresby and Welbeck seem to be the major suppliers with several trains from each.

Thoresby and Welbeck were still despatching coal to Ratcliffe well into the 2000s. The typical pattern of operation was that an empty set would start from Toton North Yard, run to a colliery like Thoresby or Welbeck for loading, run directly to the power station, with the empties returning to Toton Yard (where defective wagons could be removed before the cycle started again). In the early 2000s there were also some opencast disposal points in the local area which served Ratcliffe, places like Swains Park and Hicks Lodge (on the Coalville line) and "Forge and Monument" (a.k.a. Codnor Park) and Doe Hill on the Erewash valley between Langley Mill and Clay Cross. These disposal points would spring up close to existing lines and operate for a few years while the opencast coal was extracted. Daw Mill colliery also became a big supplier of Ratcliffe in the 2000s before the pit shut, after which the coal was mainly imported.

The cab ride video from 1987 is particularly interesting because the loaded working from Bentinck recesses in the new bank at Toton (where the line of class 60s now sits) and then runs over the old hump to access the high level goods lines into Ratcliffe. Although the hump yard itself was out of operation, most of the track was still in place, and the layout of the fans of sidings can be seen with some stored rolling stock in them.