Norte series 4600

The most important line of the Norte were the 400 miles from Madrid towards the Atlantic coast to Hendaya in France. Previously, different locomotives were needed for the long straights and the inclines. In order to be able to save time and money on changing locomotives in the future, an express locomotive was specified that had to be able to haul heavy express trains in the mountains. The requirements specified a 4-8-2 wheel arrangement, also known as “Mountain”, and also determined a four-cylinder compound engine of the De Glehn type. With a train weighing 400 tonnes, 55 km/h was to be achieved at 1.35 percent and 90 km/h at 0.5 percent. In addition, due to the ash-containing coal to be used, a large grate was required and the axle load could not be higher than 16 tonnes.

Hanomag was awarded the contract, so that six locomotives could be delivered to Spain in 1925. Although the engine was of the De Glehn type, as required, the high and low pressure cylinders were in one plane, as was usual on German locomotives. The high-pressure cylinders transmitted their power to the second and the low-pressure cylinders to the first driving axle. The frame was manufactured as a plate frame in accordance with the preferences of the Norte. The ability to negotiate curves was ensured by a bogie that could be moved laterally by 100 mm, a bissel axle that could be moved by 65 mm and weakened wheel flanges on the second and third coupled axles. Contrary to the practice among German locomotive builders, the boiler featured a Belpaire firebox with combustion chamber. 

Further production was handed over to Spanish companies. In 1927, eight came from Euskalduna, seven from Babcock & Wilcox and five from MTM. Five each from Babcock & Wilcox and MTM followed in 1928 and another ten each from these two manufacturers in 1930. The 285 mile section from Madrid to Miranda could now be completed without major stops, with two firemen working at the same time. 360 tonnes could easily be hauled on a section with a gradient of 2.1 percent and on flatter stretches the trains could even weigh 600 tonnes.

With the founding of RENFE, the locomotives were given the numbers 241-4001 to 241-4056. In 1942, 52 of the 56 locomotives were still in service, which were also distributed to other locations in the following years. Regular retirement began in 1962 and lasted until 1968. Today only 241-4001 survives. The 28 locomotives starting with 241-4048 were built as a further development between 1946 and 1948. These benefited above all from an optimization of the steam lines according to André Chapelon, a Kylchap exhaust system and Dabeg valve gear.