Blast furnaces are designed to run continuously. Letting them cool can cause serious damage, and restarting them requires extensive work. Even a planned renovation can cost millions of pounds.
The remaining furnaces at Scunthorpe are much older. The company, named Queen Anne, opened in 1954, while Queen Base has been producing steel since 1938.
Both are nearing the end of their operational lives, so restarting them once they cool down would be financially prohibitive for a company that was already losing large amounts of money.
The government wanted to keep them open because they are the last remaining source of “virgin” or new steel produced directly from iron ore in Britain.
If the plant stopped producing virgin steel, the UK would become the only member of the G7 group of leading economies that does not have the capacity to make it.
Steel production elsewhere in the country depends on electric arc furnaces (EAFs), which recycle scrap metal into new products.
Although the government’s long-term strategy is to source all domestically produced steel from the EAF, which is cheaper and much less carbon-intensive to run, it still does not want to lose production at Scunthorpe.
The plant produces steel of a type not yet made anywhere else in the country, much of it needed by Network Rail and the construction industry.
The fear was that losing this production would be disruptive and make the country too dependent on imports. It was therefore decided that Scunthorpe should remain open until alternatives became available.
There are also jobs to consider. As well as those directly employed by British Steel in Scunthorpe, the plant supports thousands of people across the supply chain.
The plant is an economic mainstay in North Lincolnshire, but the sudden closure of the furnaces could put many jobs at risk.
Simon Boyd, managing director of structural steel maker Reed Steel in Dorset, said nationalization “had to be done”.
Boyd, whose company buys thousands of tonnes from British Steel each year, told the BBC’s Today program that Jinghe was “damaging the infrastructure” at the company and the government “had to intervene”.
He said the government would need to invest heavily in British Steel and returns would not be seen for 10-20 years.
But he said it “now belongs to the British people”. He said that selling it to private investors would require government support and observed in the past that this would “benefit private companies, not the British people”.