The mining train was conceived in the minds of two Basque industrialists, who by the end of the 19th century were already well aware of the importance of synergies, because they complemented several different businesses: mining, iron and steel, shipping and port and railway construction. In 1900, Ramón de la Sota and his cousin Eduardo Aznar leased the Sierra Menera iron deposits, between Ojos Negros and Setiles. The following year they took a fundamental decision: to transport the minerals from the Teruel mines to the nearest point on the Mediterranean, which in this case prevailed over the Bay of Biscay as an export shuttle.

A new railway line would take the iron to Sagunto and there, on an uninhabited beach, a wharf would be built and a steelwork would be set up, the future “Compañía Siderúrgica del Mediterráneo” (1917). There was already a port in the area, the Grau Vell, used in Roman times. But this would be a new one, a couple of kilometres further up, making the most of the valley of the Palancia river. The initial project talked of an 800-metre quay and a breakwater to protect it from the storms of the Levante. The aim was for ships of 10,000 tonnes to dock and for it to have machinery for loading and unloading at least 5,000 tonnes a day.

The Sagunto wharf, 5 km from the city and 2 km south of the mouth of the Palancia river, thus prevailed over the idea of building a railway line to Bilbao, the nearest port to northern Europe, and the alternative of using the Aragon-Valencia train. Another key factor was that Sota y Aznar did not reach an agreement to use the existing broad-gauge central railway line of Aragon. Thus, a new, almost parallel, narrow-gauge line was born.

The Shipping Company Sota y Aznar, which carried coal from the United Kingdom to Italy, secured a freight on the return of the ships operating this route: a cargo of iron ore stowed in Sagunto to Great Britain and Germany.

The enterprising Biscayan entrepreneurs, whose land left more than one mark in Puerto de Sagunto (such as the church and school of Nuestra Señora de Begoña) wanted to speed up the company. In 1905, King Alfonso XIII visited the works and on 17th January 1907, the first steamer set sail, the Gorbea-Mendi, which transported 4,200 tons of iron to England, which had arrived via the Central de Aragón railway, in a one-off collaboration. The Ojos Negros-Sagunto railway line, 204 km long, took a few months to be completed, but in July the first wagons loaded with ore arrived: 15 hoppers full of ore (raw iron). Despite the haste of the promoters, the project was three years behind the most optimistic deadlines.

In 1913 the railway transported 948,000 tonnes of ore to the port of Sagunto. With the arrival of the Great War and the maritime blockade in the Mediterranean, extraction and transport fell to less than 125,000 in 1919. Moreover, from the beginning it was planned that the train and the port would be used to export agricultural products from the Palancia valley to Segorbe: mainly oranges and carob beans.

The history of the railway line takes centre stage in itself. It was a constant descent from 1,243 metres to sea level, which required specific braking systems. For the return journey from Sagunto to Ojos Negros it was necessary to add a locomotive in Teruel to complete the power required for the ascent to the Puerto de Escandón station.

In winter, with the snow and ice, a locomotive had to be used as a battering ram to burst the white plates and make way for the iron horse.

The business conglomerate gained new momentum from 1917, with the creation of the “Compañía Siderúrgica del Mediterráneo”, and the inauguration of the two blast furnaces at Sagunto in 1924 and 1926. The iron ore from Teruel, already exploited by the Celtiberians, was once again taking shape on the coast of Murviedro.

The Spanish Civil War seriously affected the Sierra Menera mining train. The tracks were torn up to make armour and the locomotives were moved to other uses. But at the end of the 1940s, after the Second World War, the Sagunto railway revived. The increase in the demand for iron again boosted the business, which remained in good health until the end of the 1960s.

Changes came in the 1970s. Faced with the need to increase transport capacity, the decision was taken to use the parallel Renfe line, where the former Central de Aragón had been integrated in 1941. On 29 July 1972, the last convoy of the Ojos Negros-Sagunto train unloaded at the Valencian beach.

A section of the former narrow gauge was modified and converted into a branch of the Calatayud-Grao de Valencia line. And in the following year, 1973, a record 1.5 million metric tonnes were transported. The epilogue of the mining train to Sagunto barely lasted 10 years. The world crisis of 1973 destroyed the future of the steel industry and, despite the Kawasaki report recommending that the Valencian factory should be saved from the Asturian and Basque factories, the definitive closure took place in 1984. Although that is another and controversial story.

It is estimated that the mythical Sierra Menera train transported around 45 million metric tons of ore in its 65 years of existence (1907-1972). Some studies estimate that between 80 and 110 million tonnes still remain in the Ojos Negros and Setiles deposit, but with the dubious profitability of the sector, it seems more than likely that the Green Way will be perpetuated as a more than worthy successor to that narrow-gauge line on which a young Puerto de Sagunto was born and grew up.