French Northern Railway No. 2.821 to 2.911 “Outrance”

From 1870, the Nord procured 2-4-0 express locomotives from André Koechlin with a driving wheel diameter of 2,100 mm or 6 ft 10 5/8 in. The leading axle could be shifted laterally by 10 mm. The frame was a double one with cylinders and valve gear on the inside and coupling rods with cranks on the outside. The nickname “Outrance” apparently came from the fact that the machines could be used “to the utmost” due to their durable design.

The initially installed boiler had a firebox with a round top, which lay between the driving axles. From 1877 a larger boiler was used, which had a Belpaire firebox that extended beyond the second driving axle. In addition, the boiler pressure was now 10 instead of 8.5 bars. To carry the extra weight, the leading axle was replaced with a bogie. 

The last batch, twelve of which were built in 1884 and 1885, again had only one leading axle, which was now radially adjustable. Between 1890 and 1898, all locomotives that still had a leading axle were rebuilt to a 4-4-0 wheel arrangement and fitted with the new boiler. Some received cylinders with a diameter of 460 mm and were called “Outrances renforcées”.