Fosse n° 9 de l’Escarpelle Roost-Warendin · Hauts-de-France · France

Fosse no. 9 de la Compagnie des Mines de l'Escarpelle is situated at Roost-Warendin in the Nord department, forming part of the wider Bassin Minier du Nord-Pas-de-Calais. The shaft was sunk beginning in spring 1909 using the freezing process (procédé de congélation) to contain groundwater, with a diameter of five metres. Its initial purpose was to serve as a ventilation shaft for fosses nos. 1 and 3, situated respectively 1,160 metres to the south-southeast and 1,795 metres to the southwest. Underground connections (accrochages) were established at 206 metres and at 227 metres depth in December 1909. The First World War began before the installations were operational, interrupting construction. Following post-war reconstruction, the fosse was brought into service for extraction in 1923. In 1919 the shaft had been deepened to 410 metres, and a modern extraction building with a 1,000-horsepower winding machine was constructed.

In 1950 the fosse took on a combined role: extraction, personnel and materials access, and fresh air intake, with return air handled by fosses nos. 1 and 3. In 1955 the fosse was fully modernised in connection with its designation as a siège de concentration: a lavoir was constructed, one of the largest in the region. In 1956 the existing headframe was dismantled and replaced by a more modern structure, and the steam winding machine was replaced by an electric machine. The lavoir was closed in 1968, with products thereafter dispatched to the lavoir of the fosse Barrois at Pecquencourt.

From 1965, underground connections were developed linking fosse no. 9 to fosse no. 10. In 1973 fosse no. 9 assumed responsibility for the exploitation of the coal deposit previously served by fosse no. 10. A second modernisation programme took place from 1975. The shaft was deepened to 463 metres in 1975 and the winding machine, judged too slow, was replaced by a Koepe pulley system recovered from fosse no. 13 – 13 bis of the Béthune group at Sains-en-Gohelle, which had been idle since 1972. The headframe of that fosse no. 13, dating from 1955, was carefully dismantled at Sains-en-Gohelle and reassembled over the shaft of fosse no. 9 at Roost-Warendin. The structure is a portal-beam type with solid-web sections (chevalement à faux-carré porteur de type portique à poutrelles à âme pleine), designed for double extraction with four superimposed sheave wheels of eight metres diameter; only two of the four sheave wheels were reinstalled during the transfer. In 1976, the shaft was deepened again to 570 metres. In autumn 1977, excavation of the accrochage at −540 metres was undertaken.

The last coal draws from fosse no. 9 took place on 26 October 1990 at 11:00, with coal from faces 0 and 2 of block 1. Fosse no. 9 was the last colliery to close in the Nord department; the last fosses to close across the region were those of the Dourges and Oignies groups on 21 December 1990. Total lifetime production of fosse no. 9 was 18,130,000 tonnes. The shaft, at a final depth of 592 metres, was backfilled in January 1991. The demolition of the pit yard began in January 1991 and was completed on 30 August 1991 with the demolition of the original fosse no. 9 headframe. The surviving headframe, transferred from fosse no. 13, was retained.

At the beginning of the twenty-first century, Charbonnages de France materialised the shaft head, and the BRGM undertook annual inspections. The pit yard site was progressively converted into an industrial zone. The three associated spoil heaps, nos. 136, 136A, and 138, were partially exploited and opened to the public as natural spaces. The workers' housing estates were renovated. The headframe was inscribed as a Monument Historique by order of 25 November 2009. The headframe and the cité moderne de la Belleforière, constructed between 1946 and 1956, were inscribed as components of the UNESCO World Heritage Site of the Nord-Pas-de-Calais Mining Basin on 30 June 2012.