Visiting Scunthorpe Steelworks

A few years ago I was on a camping trip with my youngest daughter and to pass the time we got on to the subject of what our favourite places in the whole world were.  It's a very absorbing topic of conversation because it's intensely personal and an opportunity to think about what things one likes doing and seeing.  I have been to some pretty amazing and mind-blowing places during my life, but interestingly when it comes down to my favourites they are, in the main, not these conventionally 'amazing' places.  They are instead places with particular fascinations and memories, and sometimes perhaps a little unexpected.  One of them is Scunthorpe Steelworks, a place I have visited many times over the years, often with parties of schoolchildren and sixth form students.  I'm motivated to write about this because I think anyone who has never visited a steelworks has missed out on what to me is something fabulously exciting and breath-taking.  I'm obviously slightly biased as someone who is interested in chemistry, but I challenge anyone not to experience an emotional response when they see at least some of the things in a steelworks (my money is on the soaker pits - see further on in this post).   

View near the blast furnaces, 24/8/19

First impressions of Scunthorpe Steelworks

My initiation into the wonders of Scunthorpe Steelworks was during the summer term of my PGCE, at Leeds University.  I knew steelworks were big, but although I knew there was one at Scunthorpe I had no idea if it was bigger than the one at Stocksbridge, where some of my family had worked.  When I saw it and realised its size I was quite staggered to say the least.  Statistics give some sense of this size, but can't really convey the hugeness of the place.  The area of Scunthorpe Steelworks is 2,800 acres.  It could easily, therefore, contain all of the Disney theme parks across the world.  All of them together, that is.  The steelworks has over 100 miles of internal railway tracks on site, with a fleet of 20 locomotives.  They even have their own police force and small hospital.  Naturally lots of things are on an industrial scale.  The gas pipe serving the bloom and billet mill is 9 feet in diameter, large enough to drive a Land Rover through (something that was done as a publicity stunt when it was installed).  The building which houses the Basic Oxygen Steelmaking process is high enough to fit St Paul's Cathedral inside.  This huge size tells its own story of the evolution and importance of the site, but it also reveals the scale of the operation of industrial steelmaking.  This is heavy industry on a grand scale. 

What I remember about my first visit to the steelworks was the excitement arising from the sheer assault on my senses.  This was not only from the sights, sounds and smells.  What really set it apart was the blistering heat from red hot metal, even though we were always a safe distance from it.  It was a visceral experience, with sights that are simply not part of an ordinary everyday existence outside a steelworks.  Indeed I can say quite truthfully that there are certain sights in a steelworks that produce powerful emotions.  One of these emotions is definitely fear, and later in this blog post I will describe what for me is probably the most terrifying spectacle I have ever seen.  The thrill of the steelworks is therefore in some ways akin to a theme park, where pleasure is derived from things which actually scare you.  The difference is that in a theme park you know the scares are manufactured; in a steelworks they aren't, and serious injury or death are literally around many corners - to the unwary at least.  Inside cavernous and gloomy rolling mills, for example, the speed and violence with which huge red hot billets of steel were crashed into rollers to change their shape was almost unbelievable.  Noise, heat, and clouds of condensation from cooling water combined to make an other-worldly atmosphere. In fact there was a sort of hypnotic quality to watching things like the rollers in rolling mills, because it was just so remarkable that powerful machines like these even existed.  Industrial machinery makes the machines of domestic life seem puny by comparison.  In one of the mills, the now sadly defunct heavy section mill, this process was controlled by workers sitting in cubicles overlooking the rollers, operating them with little joysticks.  They sent the multi-tonne billets careering back and forth like toys, causing wafer-like layers of hot metal oxide ('mill scale') to sheer off the surface each time.  Once each glowing red billet had been suitably re-shaped and re-sized through one set of rollers it proceeded down the mill conveyor to the next set.  Observing this was very exciting.  You could feel the billet as it came towards you because not only did the ground shake, but the heat it was giving off was palpable from a distance of several metres.  Although I never visited the heavy section mill again, I observed similar processes on subsequent visits in other rolling mills, though these were controlled automatically with no human supervision required.  What was interesting was to observe how the process of rolling hot steel not only changed the profile of the cross-section, but in lengthening it there was a knock-on effect of increasing the speed at which the steel emerged at the other side of the roller.  This is unexpected to an unenlightened observer, but it is something which has to be accounted for in calculations about the safe and efficient operation of the mill.  

29/6/19 The air shimmers above a stack of hot steel billets.  These would still be far too hot to touch, though they are well below 'red heat'.

 

Basic Oxygen Steelmaking

The size of the steelworks means that any decent tour of the site has to be conducted on the internal road network, with periodic stops to visit the various points of interest.  On the numerous tours I have been on over the years, we have always been accompanied by retired workers who know the site and are very knowledgeable about the processes going on.  Without their encyclopaedic knowledge it would be hard to make sense of the site and what everything is.  There have been plenty of highlights, and a few are worth recording here.  Visiting the Basic Oxygen Steelmaking (BOS) Plant is always exciting, if only for the scale of the operation.  The bucket in which the process is carried out is the size of a small house, and is hoisted by a gargantuan overhead crane.  The process is so hazardous that nobody is even allowed to watch it apart from on video monitors.  It is controlled from a room overlooking the bucket, packed with buttons and consoles, but when the process actually occurs this room has to have steel shutters closed over the windows, due to the risks.  A pipe called a lance is lowered into the bucket of molten iron, and then oxygen gas is blown through the pipe into the iron at incredibly high pressure.  The lance is water cooled because it would obviously melt otherwise, and the oxygen leaves the tip at more than twice the speed of sound.  The sound of the BOS process therefore is something akin to a jet aircraft, and it is accompanied by an eruption of white hot sparks.  The oxygen reacts with impurities such as carbon in the iron, turning it into carbon dioxide, so that it is removed as a gas.  Measured amounts of other  metals can be put into the bucket to make steel of desired compositions. 

The BOS plant, with glowing slag bucket in right foreground, 29/6/19.  This building could contain St Paul's Cathedral.

Coke making

Another highlight at the steelworks is seeing a coke 'push'.  Scunthorpe has its own coke works for making the coke which goes into the blast furnaces.  In coke making coal is heated to a high temperature in the absence of air for about eighteen hours, to drive off all the volatile compounds in it and basically leave just carbon.  After eighteen hours the doors of the huge furnace are opened and the coke is pushed out with a hydraulic ram - hence why it is called a coke push.  What makes this exciting is that the moment the red hot coke meets the air it bursts into flame, so what you see is a huge cascade of orange flame as the coke falls into the waiting coke car, a special railway wagon.  It continues to burn and glow in the coke car, but not for long, because the driver of the coke car has to quickly push it to the nearby quenching tower where tons of cold water are unceremoniously dumped on to it.  This quickly cools the coke so that it emerges black and steaming, but it also sends up a huge white cloud hundreds of feet into the air.  The coking plant is probably where the olfactory sensations are at their most potent.  Smoke and fumes, some unpleasant and others tolerable, are the order of the day.  Personally, I've always quite liked this sort of thing, but a coking plant is undeniably heavy industry at its dirtiest.

Back of the coking ovens, 24/8/19.  Each vertical strip is a furnace; collectively they form what is called a battery.  Flames can be seen at the top of some where the door seal is not complete.

The Terror of the Soaker Pits

My final highlight, and probably the most awe-inspiring part of any trip I've done to the steelworks, is a visit to the terrifying and unearthly soaker pits.  There is something humbling in seeing things that are truly frightening, and few things make me weak at the knees like soaker pits.  The name gives no hint of the sheer terror that they can inspire, and before I had seen them I had no idea what they were.  The basic idea which necessitates soaker pits is that large ingots of cast steel need to be hot enough for rolling into shaped sections.  Because the rate of production of ingots, and the distance they have to travel from the casting mill to the rollers, it is not possible for the process to just happen continuously without cooling of the ingots while they are waiting to be rolled.  This is where the soaker pits come in.  They are essentially just huge warming ovens near to the start of the rolling mill rollers, but a comparison to an oven is, I have to say, grossly misleading.  What makes them terrifying is their size, temperature and the fact they are pits.  In other words, you could fall in.  The prospect is beyond horrific.  It is hard to imagine that such places exist just a couple of miles from a town with all the usual hallmarks of normality like houses, shops and schools, because looking into a soaker pit is to be temporarily transported to a different, unimaginably gruesome world.  It was possible to view the Scunthorpe soaker pits from a balcony which, I would guess, was about 15m above ground level.  There were maybe a dozen pits, each covered with huge bi-folding steel doors.  When, periodically, the doors opened and you could look down into one of the pits it was like nothing I have ever seen elsewhere - a vision of some fiery hell.  I can vividly recall the radiant heat hitting my forehead and the feeling like my eyebrows were being stripped from my face (they weren't, fortunately).  The whole inside of the 20-foot deep pit was incandescent from the high temperature.  The steel ingots themselves were virtually white hot, and there was a worker whose job was to operate an overhead crane to remove them, or put freshly cast ones in.  His air-conditioned cab placed him directly above the pits, where to fall in would mean not just instant death but instant cremation.  It doesn't bear thinking about.  There are echoes of the final scenes of "Terminator 2" but a real soaker pit is far worse than this, if only because part of your brain knows that scenes from a film are not real, whereas real industrial accidents can be grisly beyond the imagination of Hollywood filmmakers.  Our guides would always tell us that the man in the crane cab was on a higher salary than the works manager; a compensation for the extremely precarious nature of his work.  Having said that, nobody at Scunthorpe ever told me anyone had fallen into a soaker pit; not at their works anyway.  If it did happen, there wouldn't be much left.  All one's organic matter would become carbon dioxide and other gaseous products in seconds.  Bones and teeth would probably end up as calcium oxide.  There is a tale I have read at https://otjc.org.uk/from-school-to-steelworks/ which describes a worker who threw himself into a soaker pit at the Parkgate steelworks near Rotherham.  It sends a chill down the spine.  "They said he was dead before he hit the bottom of the soaking pit, as he fell in it he disappeared and turned into a wisp of smoke."  Of course, it is not possible to verify if one would be dead before hitting the bottom of the pit, but I don't doubt this assertion.  The boiling and combustion of body tissues would happen so quickly that there would probably be no consciousness of anything mere moments after beginning to fall, and death would be virtually instantaneous.  There would certainly be no remains to go in the coffin.  So would there even be a coffin at a funeral?  The link above suggests there is.  Workers who die in accidents in steelworks which leave little in terms of human remains have a piece of steel put in the coffin.

To see a picture of one of the soaker pits at Scunthorpe, click here.  The photograph gives a sense of the white heat inside, but obviously without feeling the heat!  There is a video which shows the view from the inside of a crane operator's cab, removing ingots from a soaker pit (not at Scunthorpe) here.  (You will need to go to 7:30 on the film).

Continuous Casting

I'm not sure whether the soaker pits are still in operation at Scunthorpe.  From an economic viewpoint they are part of a process which is inherently wasteful, in terms of energy.  The requirement for natural gas, and the greenhouse emissions resulting from their operation must be huge (although heavy industry is very good at self-sufficiency, and at least some of the energy requirements on site are met by processes such as coke-making, which produces a lot of combustible gas).  The more efficient way to produce cast steel is to avoid the need to reheat it once cast, and this is by the process called continuous casting, which is something Scunthorpe does on a large scale.  Continuous casting is also fascinating to watch, and again brings you close to red hot steel.  The key to the process is to let the solidifying steel emerge through a shaped hole in the bottom of a vessel called a tundish and then just keep doing this continually.  The steel is sufficiently solid to be able to be pulled away on conveyors, like hot metal spaghetti.  The tundish requires a continuous supply of molten steel therefore, and the emerging cast steel needs somewhere to go and some way to be cut into required lengths.  The oxy-acetylene cutters themselves are fascinating to watch, because they have to move with the slow-moving steel as the cut is made, to ensure it is straight.  The whole process is a brilliant example of industrial automation, as well as human ingenuity.  Continuous casting is necessary for making products like rail for railways, and Scunthorpe is a major centre for production of this.  

29/6/19 Rail produced by continuous casting.  Notice how the rail can flex - it has to be able to do this to be transported.  

Visiting Scunthorpe Steelworks

Although the things described in this post are from visits in which the insides of the buildings at the steelworks were observed, it is possible to visit Scunthorpe Steelworks for free by riding on a train around the site.  Details of how to do this can be found here.  Although this does not take you into the rolling mills where some of the things described here are happening, it is still a great way to appreciate the site and what happens on it.

  

Recently emptied slag bucket, 29/6/19.  This was a lucky sight during one of my rail visits.

All the photographs in this blog post are my own.  You can see more of them here.