The last blast furnace at one of the biggest steelworks in the world is shutting down, leaving it unable to make its own virgin steel.

Nearly 2,000 jobs will be lost at Tata Steel UK’s Port Talbot plant as blast furnace number four ceases production.

The ironworks will enter a transition phase until 2027 when steelmaking will resume through a £1.25 billion electric arc furnace.

The new furnace uses electric current to melt scrap steel or iron to produce steel, whereas blast furnaces use coke, a carbon-intensive fuel made from coal to produce steel.

Moving to electric arc steel production will reduce the UK’s overall CO2 emissions by around 1.5%.

In its heyday during the 1960s, more than 18,000 people were employed at Port Talbot’s Abbey steelworks.

But the site has gone through many periods of change, which has sometimes resulted in strikes and job cuts.

Indian conglomerate Tata purchased the steelworks in 2007.

Dean Cartwright, the works manager for coke, sinter and iron, said local residents will see larger plumes as steam coming from the furnace as production is wound down, as well as prolonged “whooshing” sounds.

“We have started to change the burden – the raw materials we put in the top of the furnace – to make sure the slag formed on top of the iron is the right type for this process, and reducing the amount of coal we inject into the furnace,” he said.

“Over the next four days, we will stop adding new raw materials and bring the burden down to low levels within the furnace.

“Please remember that we have our experts monitoring every single aspect of this process as it progresses, to ensure we bring the furnace to a close safely and calmly.”

As the second of its two blast furnaces ceases production, businesses in the supply chain impacted by the closure can seek funding to overcome short-term challenges.

They can apply to the supply chain transition flexible fund, which is part of an overall £80 million package provided by the UK Government.

The fund will be delivered through a partnership between Neath Port Talbot Council and the Welsh Government’s Business Wales.

Welsh Secretary Jo Stevens, who is chairwoman of the Port Talbot transition board, said: “Businesses and workers that supply Tata have been feeling the impact of the changes at Port Talbot for months.

“That’s why I announced this £13.5 million fund within weeks of the new UK Government coming into office, and have worked at pace with partners in Welsh Government and the council to get applications open.

“I encourage affected businesses to come forward and check their eligibility for this financial support, as part of the wider support package we are putting in place. This Government will back workers and businesses whatever happens.”

Rebecca Evans, the Welsh Government’s Economy, Energy and Planning Secretary, said: “The closure of the blast furnaces at Tata Steel UK have caused concern and uncertainty for many, both currently working at the steelworks and amongst its significant local supply chain.

“This fund is focused exclusively on supporting those businesses substantially reliant on Tata Steel UK, which will be impacted by the blast furnace closures to help mitigate the impact and plan for a positive future.

“I would encourage any supply chain business affected by the transition to use the eligibility checker to access support through Business Wales.”

Earlier this month, the UK Government announced a £500 million package to help the Port Talbot plant transition to greener, low carbon steel production.

It has also improved the redundancy package on offer to workers – with full-time staff getting a minimum of £15,000, plus a £5,000 retention payment and paid-for training.

Under the deal, the Government can claw back some of the £500 million invested if Tata does not fulfil its commitments, which includes retaining 5,000 jobs across its UK businesses post-transformation.

Tata will also be releasing 385 acres of the Port Talbot site for industrial redevelopment.

Around 500 jobs are expected to be created during the construction of the electric arc furnace.

Community union general secretary Roy Rickhuss said: “Today marks an incredibly sad and poignant day for the British steel industry and for the communities in and around Port Talbot which are so intricately connected to blast furnace steelmaking.

“It’s also a moment of huge frustration – it simply didn’t have to be this way. Last year Community and GMB published a credible alternative plan for Port Talbot which would have ensured a fair transition to green steelmaking and prevented compulsory redundancies. Tata’s decision to reject that plan will go down as an historic missed opportunity.

“Through months of intense and challenging negotiations, we secured firm commitments from Tata on future investment in the businesses. The deal we negotiated, which has been strengthened by the intervention of the Labour Government, is a significant improvement on the dreadful deal between Tata and the Tories.

“However, this will be of little consolation to those who are losing their jobs. We will support those workers in every way we can, including through the employment and skills support centre we have opened in the heart of Port Talbot, in partnership with the Welsh Government.

“The skills and retention scheme we negotiated with Tata is going to be vital. The scheme gives workers up to an additional year of employment to gain new skills to find new employment, and importantly participants will be prioritised where there are vacancies in the company.

“The closure of blast furnace four marks the end of an era, but this is not the end for Port Talbot. We will never stop fighting for our steel industry and our communities in South Wales.”

The Conservatives and Labour share the blame for the lack of an industrial strategy, according to Plaid Cymru.

Economy spokesman Luke Fletcher MS said: “During the general election, Labour promised a better deal for the Port Talbot steelworks.

“Today the second of its two blast furnaces shuts down. This is more than just a factory closing, it’s the end of Welsh steelmaking and the livelihoods of countless workers and families.

“The decline of our steel industry is a direct consequence of successive governments failing to develop an industrial strategy.

“They neglected to acknowledge that without a strong steel sector, the car industry, shipbuilding, and heavy manufacturing are all doomed to fail.

“While other nations recognised the vital importance of domestic steel production and actively subsidised it, the UK chose to privatise and sell our steel assets to foreign entities, making us reliant on imports.”