Cwm Cokeworks, Tynant - May 2010

[wolfism]

A visit to Cwm is a revelation into the black art of cokemaking. It is also one of few abandoned industrial sites in the UK which can properly rival the scale of derelict industry on the Continent. It’s a rotting massif of iron and concrete. Cwm is the dying shot of the Welsh coal industry and the death throes of steelmaking in the Valleys, all rolled into one. It’s the reclamation of industrial revolution Britain by nature, and the upshot of shit-soft environmental laws in this country which allow cyclical hydrocarbons to trickle into the earth, poisoning the village of Beddau and the farmland around it. Most of all, the cokeworks is disreputable and creaking in its old age, a gin-shot dowager passed out in a ditch.


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Beddau is a sprawling village which grew up around the Cwm Colliery, a coal mine that was sunk in 1909 and opened in 1912. The colliery disappeared long ago, but the coking works is still here and extends up a narrow valley, with a spoil bing on one side, and rolling fields on the other. The tops of the towers and bunkers poke up above the treeline, grimy artefacts set in an otherwise green valley. It has an interesting history. At vesting time in 1947, the National Coal Board inherited several coke plants, all old and relatively small, at Bargoed, Maritime, Coedely and Tondu collieries. The NCB were keen to centralise the production of foundry or ”metallurgical” coke, and that demanded a site large enough to deal with about one million tons of coal a year, and with an adequate water supply. Cwm colliery had room for a new coke plant if the existing stream and road were diverted, but the colliery output was far too small, although the coal itself was ideal for the purpose. In the end it was decided to raise coal at four neighbouring pits and divert their output to Cwm’s shafts.


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A contract was placed with Simon-Carves Ltd. around 1955 for the megaton-scale coking plant and its power station, which produced 8,000 kW for the colliery grid. Construction progressed rapidly, once the enabling works were out of the way, because the structures are straightforward: the bunkers are reinforced concrete, the ovens similar with steel bracing, and the ancillary buildings have concrete frames with brick spandrel infills. The new plant was described in the “Coke and Gas Magazine” issues of May and June 1959, and the narrative helps to explain the relatively simple process of making coke – which only looks complex due to the plumber’s nightmare surrounding the coke ovens. First off, coal headed up conveyors from a railway wagon tippler on the western side, passing through hammer mills which crushed it, then through screens and into the four 500-ton blending bunkers. From there, another conveyor belt leads up to the 3000 ton coal service bunker, which is the tall concrete tower in the middle of the site, sitting above the main coke oven battery.


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An oven charger or “larry car” travelled along the top of the coke battery, was loaded with pulverised coal by the bunker, then travelled out and fed it in turn into the coke ovens from above. The coke ovens had charge holes with steel flaps on top which the larry car flipped open. Each of the 108 coke ovens reduced the coal to coke at around 1250 deg.C in an oxygen-poor atmosphere: as the coal is heated, volatiles are driven off and you’re left with a hard, porous mass of coke which is almost pure carbon. After thirty hours in the oven, the coke was ready, and was emptied horizontally by a mechanical pusher, which discharged it into a rail-mounted “coke car”. This second car carried it to the quencher, a circular concrete water tower under which it was rapidly cooled, creating huge clouds of steam. The plant’s throughput was 1,350 tons a day and the cooled coke was then conveyed to the coke bank, then a screening plant from where it was loaded into railway wagons.


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Simon-Carves used their own design of oven at Cwm, whereas other British coking plants used Woodall-Duckham “Becker”-type regenerative coke ovens. Each oven is a 450mm slot formed in a wall of refractory bricks, and the bank of ovens is held together by steel buckstays and tie rods, now very, very corroded. The gas produced by the ovens as the coal became pure carbon was drawn off through ascension pipes by an exhauster plant on the eastern side of the coke batteries, with steam turbines driving exhausters to pull the gas into purifiers. From there, it was scrubbed and its by-products separated: while the gas was taken to gas holders via a booster house with reciprocating compressors, the ammonia and crude benzole were separated in the fractioning towers. Some of the gas was used to fire the works, and the remainder was sold to the South Wales Gas Board, with the chemicals sold on to chemical companies. The stinking residues of coal tar, ammonia and benzolic chemicals linger on…


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Cwm has a few quirks. The timber cooling towers are the last survivors of a type which was invented in Germany in 1894, but almost every other one was replaced by paraboloid concrete towers in the 1950’s. Why the timber towers were built here in 1958 is a mystery, since the rest of the works was state of the art … although never having been modernised since then, it was decrepit and largely obsolete by the time it was closed. In fact, there are few coking plants left now, with only South Bank and Redcar on Teeside; Dawes Lane and Appleby at Scunthorpe; Morfa at Port Talbot; and Monckton Coke at Royston still operating. Llanwern closed a few years ago, and the massive banks of ovens at Ravenscraig, Europe’s largest steelworks, almost two decades ago: many others disappeared as the coal industry shrank. In fact Ravenscraig dwarfed Cwm: its coke ovens were four times the size of the Welsh site.


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Cwm Colliery was closed by the NCB in 1986: the coking plant survived the closure of its colliery, but in its final years it was reduced to supplying barbecue coke. It ceased production in June 2002 and has sat festering ever since. Now the top of the coke oven battery is a wilderness of saplings, and moss has settled on the concrete: it seems that minerals in the coal and coke work well as fertilisers, as they have raised a fine crop of weeds and shrubs. The concrete structure here will last for hundreds of years … but the steel sections have been attacked by heat, acidic gases and the damp atmosphere, so some parts of the structure aren’t to be trusted. The site’s owners CPL (Coal Products Ltd.) plan to carry out reclamation works on the site, but due to the land’s low value (no great demand for housing here) and the high cost of remediating the contamination, this process may take a while to carry out.

Meanwhile, it keeps a couple of men and a dog in gainful employment…

[skin]

Grand stuff Wolfie, grand stuff - I like this one quite a lot.

[sinnerman]

excellent report fella one of the best ive seen on Cwm, ive spent a long time trying to find information on Cwm and its pretty scarce so your reports been a good read.

[Runner]

Great report there mate, very interesting stuff and good pics too
The quenchers are pretty awesome to see, especially on a cold day.

[boxfrenzy]

That is very impressive, and the shots give a real idea of how big the site is. Again, an excellent write up.

[Cuban Bloodhound]

Good one Wolfie, this is one industrial site I'd really like to visit. Do you know if it's went down hill much over the past year or two?

[magoo²]

Cracking stuff there wolfism! nice one

[sinnerman]

Good one Wolfie, this is one industrial site I'd really like to visit. Do you know if it's went down hill much over the past year or two?

Its went a little bit down hill every time ive visited over the past 3 years but its still well worth the effort.

[wolfism]

Cheers everyone, this was another ambition fulfilled.

Sinnerman – I've got some more history somewhere, that Coal & Coke magazine was a riveting read! Cuban – as Sinnerman says it's no doubt gradually got worse over time. TC – AFAIK the cooling towers are the only part of Cwm that are listed, but I didn't get close enough to see whether the timber's still sound.

I'm chuffed atm as I managed to find a Simon-Carves coke oven advert in one of my books about Ravenscraig, so will scan it at the weekend if anyone wants to see it?

[wolfism]

For a while every factory I explored seemed to have either had Ellison switchgear or columns made by Lanarkshire Steel Co… recently it’s been “Simons”. It’s another example of the inter-connectedness of everything: Simon-Carves was an engineering company based in Stockport, whose roots lie in the inventions of Henry Simon, who began making flour-milling machines in the 1860’s. His company became the Simon Engineering Group, and as well as the coke ovens at Cwm, they also made coal washeries; the chemical engineering part of the group built sulphuric acid plants and similar things. Other Simon machines I’ve spotted were the roller mills at Clarence Mills in Hull, and also the handful of machines remaining on the seventh floor of Millennium Mills in London.