Belgian State 4-6-2 Locomotives in Belgium

Class Type 10 (Locobase 2531)

Data from Gustav Reder (1974), supplemented by cnum_8XAE739, Exposition universelle, Groupe VII. Classes 39 et 40: Industrie des Transports-Chemins de fer et Tramways. Exposition internationale des industries et du travail de Turin 1911 (Paris: Comite Francais des Expositions a l'Etranger, 1911), p. 18. See also J B Flamme, Les Materiel des Chemins de Fer a L'Exposition universelle et internationale de Bruxelles de 1910 (Paris: H. Dunod et E Pinat, 1911), pp. 567 for detailed descriptions and diagrams.; and "Pacific Express Locomotive, Belgian State Railways," The Locomotive, Volume 16 (15 July 1910), p. 136.

Commenting on the physical appearance of this class, Reder wrote that it reflected the high permitted axle loading. Because the boiler's weight rested exclusively on the rear four axles (three driving, one trailing), B. Flamme could position the four cylinders in front of the smokebox over the center of the leading bogie. "This gave the impression that these engines were pushing their own cylinders in front of them." Combine that with a long boiler showing a sharp taper at mid-length and you have an odd-looking engine. (Locomotive Magazine's photo reveals the incongruous arrangement.) Yet they showed considerable power, being able to pull a 381-ton train up a 1.6% grade at 31 mph (2,390 IHP).

One set of valve gear located inside of the crosshead directly actuated the valves on the outside cylinder. Tail rods extended forward and moved rocking arms that actuated the inside valves and cylinder.

The one imperfection in the design was a firebox that over-burdened the trailing truck. The last 30 had a shorter firebox. All were reworked according to Chapelon's findings during the late 1930s. Modifications included a further expansion of superheat area to 816 sq ft (75.8 sq m) and the Kylchap exhaust. Such an increase in power led to a tonnage rating climb to 500 tons.

NB: The tube heating surface area used in the evaporative heating surface total shows the water side (outside) diameter. When calculated from the fire side (inside) diameter, its evaporative heating surface area amounted to 220 sq m (2,368 sq ft).