A coke-fired furnace was established in around 1797. It was situated 800 metres north of Cinderford bridge and used coke brought from Broadmoor, to the north, by a short canal. The furnace struggled to compete with iron furnaces elsewhere, and fell idle ten years later. It was revived in 1829 when new works on the old site were established by the Forest of Dean Iron Company, and in 1841 there were three furnaces producing 12,000 tons of iron a year and employing 100 men and boys. Only one furnace at the works was in blast in 1890 and the works closed in 1894. By the 1840s Cinderford had a number of foundries and small engineering firms supplying the mining industry with machine parts, and it remained a centre for metal industries in the early 20th century. For many years coal mining was the principal industry in the area. Lightmoor coal mine was being deepened in the late 1830s. Trafalgar colliery which was in production in 1860, was the only large mine in the coalfield run by free miners in the later 19th century. Trafalgar closed in 1925. A deep mine, called Northern United, was begun north-west of Cinderford in 1933, but Lightmoor, with a workforce of 600 in 1934, was the main colliery in the Cinderford area until it closed in 1940. There were still many smaller collieries in the Forest of Dean, employing 84.5 per cent of the adult male population in the Cinderford area, until the industry declined in the 1960s.