A few years before the First World War, Jean-Baptiste Flamme developed a very powerful boiler that was to be installed in a goods and an express locomotive at the same time. In 1909 the type 36 with 2-10-0 wheel arrangement and in 1910 the Pacific of the type 10 were created. The boilers differed only in the firebox, which had enough space between the last driving axle and the trailing axle on the type 10, but had to be accommodated above the last two driving axles on the type 36.
The very large firebox had a direct heating surface of 19 square meters and included a grate of 5.1 square meters. The long boiler tapered in front of the firebox, but still had a large diameter in the front area. It made the type 36 the most powerful goods locomotive in Europe.
To ensure curve negotiation, the leading axle was combined with the first coupled axle to form a Zara bogie, and the last driving axle had 29 mm of lateral play. The four cylinders were all in one plane and were only controlled by two external Walschaerts valve gears for easier maintenance. The inner cylinders acted on the second driving axle, and the outer ones on the third.
In a first batch, 136 were completed, 17 more followed after the First World War. 113 of the pre-war locomotives were rescued to France during the war, where they were not used due to their high axle loads. As early as 1915, 60 were sold to Russia, where they were to be used on standard-gauge lines in Eastern Europe. Ultimately, they were converted to broad gauge and used in the Soviet Union until 1962.
The locomotives returned to Belgium were fitted with double blast pipes and longer smokeboxes in the 1920s. Together with other smaller conversions that were made up to the early forties, the service weight increased by almost four tons and the power to 2,300 hp. They were now designated type 36bis and were used until 1947.
