Marcegaglia steelworks video: Mystery of 'explosion' seen over Sheffield is solved as residents are reassured
and live on Freeview channel 276
The mystery of an 'explosion' seen for miles across Sheffield, creating a spectacular orange and red glow above the city, has been solved.
The Star shared footage earlier this month of what one reader described as a 'massive explosion' which had been recorded from Woodhouse Mill. It showed what looked like an orange fireball rising into the night sky before rapidly disappearing.
Advertisement
Hide AdAdvertisement
Hide AdNow new footage of the same phenomenon has been shared on X (formerly Twitter) by the Sheffield WeatherCam account, showing the source to be a steelworks in Tinsley, Sheffield.
Site in Tinsley can melt 250,000 tonnes of scrap a year
Sharing the video, Craig Thompson, who runs the account, said it showed a 'huge explosion of molten steel slag' at the old Outokumpu steelworks which was recently bought by the Italian firm Marcegaglia Stainless Ltd.
He told The Star the process is visible three or four times a night but looks more spectacular when it's raining as the molten steel slag hits the cold water and 'goes with a bang'.
The Star reported in April how Marcegaglia had bought three sites including the famous SMACC (Stainless Melting and Continuous Casting) meltshop in Tinsley, which is powered by electricity and can melt 250,000 tonnes of scrap a year.
Advertisement
Hide AdAdvertisement
Hide AdThe company said at the time it was creating 40 jobs and 20 apprenticeships and was keen to ‘invest and increase volume’.
The SMACC site off Europa Link in Tinsley was previously owned British Steel Stainless, Avesta Sheffield and most recently the Finnish firm Outokumpu.
Strange glow over Sheffield explained by steel firm
Responding to the footage shared by the Sheffield WeatherCam account, a spokesperson for Marcegaglia said: "At the Marcegaglia Sheffield Stainless meltshop steel is produced using 90 per cent recycled content.
"As part of the process an inert product is produced, often referred to as slag. The slag as part of its recycling process, is tipped into specially created lagoons to cool and then further break up. This material is then recycled to roadstone.
Advertisement
Hide AdAdvertisement
Hide Ad"Given that the slag is in a molten state it glows red before cooling. Under certain atmospheric conditions (mist, drizzle, low cloud), this colour is reflected by the water particles in the sky giving the glow that has been reported.
"Please be assured this is not the result of an explosion or an uncontrolled event, just part of the normal 'Green Steel' production here in Sheffield."
Comment Guidelines
National World encourages reader discussion on our stories. User feedback, insights and back-and-forth exchanges add a rich layer of context to reporting. Please review our Community Guidelines before commenting.