ArcelorMittal Dunkirk: behind the blast furnaces, an entire ecosystem on borrowed time

Dunkirk (North), private correspondence.

With 3,200 permanent jobs in Dunkirk and 630 in Mardyck, plus hundreds of temporary workers and permanent subcontractors, ArcelorMittal is by far the largest employer in this metropolitan area of ​​190,000 inhabitants. Serge Ballat, secretary of the local CGT metallurgy union in Dunkirk, himself an electrician in a company that works for ArcelorMittal, estimates that the number of more or less regular subcontracted employees at the two sites is 3,000 to 5,000.

Many of these companies are based in Dunkirk or Hauts-de-France, but some come from much further afield. According to him, "ArcelorMittal has been forced to broaden its range" because many are scalded by payment terms that reach 120 to 160 days, whereas "a normal contract is 45 or 60 days, exceptionally 90" .

The lime and limestone that feed the two Dunkirk blast furnaces come from the neighboring department of Pas-de-Calais, where the Carrières du Boulonnais group (600 employees) operates one of its seven French quarries. This raw material arrives at the factory by train, via the Grande-Synthe sorting yard .

If we add the steel shipments that pass through this same station, "ArcelorMittal represents 80% of our business," estimates Olivier Lefebvre, of the CGT railway workers, one of the 120 agents who still work at the sorting yard. And if smaller local customers find a place on "multi-batch trains," it is because the profitability of the latter is ensured by the large quantity of goods entrusted by the steelmaker. "This allows small shippers to also benefit from rail transport," summarizes Olivier Lefebvre.

Another local logistics facility heavily used by blast furnaces and rolling mills: the port of Dunkirk, which has 377 employees, but "30,600 direct, indirect and induced jobs" , according to its 2023 activity report. And when ArcelorMittal catches a cold, the port coughs.

Thus, in 2023, one of Dunkirk's two blast furnaces was shut down for several weeks after an explosion at the end of March. As a result, the port recorded a 25% drop in its ore traffic that same year. This represents a loss of approximately 2 million tonnes, out of a total activity of 44 million tonnes, including all traffic.

Many major customers in the region depend on the steelmaker's deliveries. Among them is the Toyota plant, which employs more than 5,000 people in the Valenciennes region , including 3,800 permanent employees. "They're a customer we pamper, very demanding when it comes to quality," explains Ludovic Putter of the CGT ArcelorMittal Mardyck union. "We deliver a product that not everyone can produce: zinc-coated sheet metal, with the exact weight, thickness, and roughness."

Others use by-products from the Dunkirk and Mardyck sites. The DK6 power plant (Engie group) produces electricity from the combustion of gases produced by the two blast furnaces. That's twice 400 megawatts, "the equivalent of a small nuclear unit," says Stéphane Avonture, CGT representative at this site, which employs 75 people. "It's a unique engineering technique, created to measure. If ArcelorMittal no longer supplies us with gas, we no longer have a reason to exist and no possibility of conversion," he insists.

As for the heat from the steel produced, it is used to power an urban heating network. Until 2019, 6,000 collective housing units in Dunkirk were connected to it, as well as swimming pools, middle and high schools, the headquarters of the Dunkirk Urban Community (CUD)... In 2020, it was extended to gradually serve other towns in the urban area, starting with the polyclinic, apartment buildings, and municipal buildings in Grande-Synthe.

Another issue for the CUD: the DK'Bus public transport network, which already represents "a subsidy of 16 to 17 million euros to finance free bus travel and the development of the service," points out Delphine Castelli, PCF deputy at Dunkirk town hall and CUD advisor. For his part, Gaëtan Lecocq, of the CGT ArcelorMittal Dunkerque, estimates the annual sum paid by his employer to DK'Bus at 3 million euros. This would seriously complicate the equation if this source of funding were to disappear.