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Steam Locomotion in the 21st Century

The Recent History of Steam Locomotive Development

Dutch "Tram" Locomotive RTM 56

updated 7 February 2022

Dutch tram
                    locomotive RTM56

Dutch "Tram" Locomotive RTM 56

In the 1990's, Dr. Jos Koopmans of the Netherlands, did extensive research on the physics of steam locomotive exhausts systems with the goal of developing a more-complete understanding of their operation. To test his ideas about exhaust system performance, RTM 56 was used for exhaust tests in December of 1999. Including water and coal it weighs 22 tons. In the picture the electronic interface case between the computer and the sensors is clearly visibly, as is a cable from the smokebox temperature sensor and the flexible copper tube for the smokebox vacuum. The photo below shows the blast pipe with the 4-fold orifice crown with 40 mm inserts in place.

The tests confirmed Dr. Koopmans' theories about the function of multiple-nozzle exhaust systems, which are covered in detail in his paper "Unified Exhaust Theory for Steam Locomotives". This theory became the basis of Jos' PhD thesis, which he later expanded into a book which is covered on this site on the Exhaust Systems page.

4-nozzle exhaust stand
                    tested on RTM 56