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Compound de Glehn steam engine Compound de Glehn, a German-made steam engine used on the railways of the Ottoman Empire, 1894-1912,
Thessaloniki, Greek Railways Organization Engine-shed. Built by Batignolles in 1907 (Works No 1594) Ex Piraeus - Demerli - Frontiers railway line (PDS) #B 206. The sole survivor of its kind in Europe. Briefly stated, four early steam locomotive types were as follows:
De Glehn. The name given to a French system of compounding used at the turn of the century. High-pressure cylinders, outside and behind smoke-box, driving the rear drivers. Low-pressure cylinders, inside under smoke-box, driving crank axle of front drivers. Four separate slide valves and four Walschaert valve gears allowing independent regulation of the high- and low-pressure valves. Compounding used the steam twice, once in a high-pressure cylinder and then in a low-pressure cylinder.
Although France had been the cradle of dual expansion applied to the locomotives, it is not at all in her place that the compound locomotive has covered all the phases of her development; It's in Germany almost, thanks to the persevering efforts of von Borries, that the compound mode spreaded the most easily. In 1890, ten years after the first application of the system in this country, not less than 430 two cylinders compound were counted.
France get started right away in the 4 cylinder compound mode; It's in this way that the first compound intended to a major company was set up in 1886 (10 years after the first Mallet's machine) on the network of the Nord; She had been built upon the initiative of Mr. de Glehn, engineer of the Société Alsacienne de Constructions Mécaniques, in the factories of this company.
Cole. High-pressure cylinders, inside but in advance of the smoke-box, driving front axle. Low-pressure cylinders, outside in line with the smoke-box, driving rear driving axle. Two piston valves on a single stem serve the steam distribution for each pair of cylinders, and each valve stem is worked from an ordinary link motion.
Vauclain. High-pressure cylinders inside and low-pressure cylinders outside, all on the same horizontal plane, in line with the smokebox and all driving the front driving axle. As in the von Borries, a single piston valve worked from a single link effects the steam distribution for the pair of cylinders on each Side.
Von Borries. High-pressure cylinders inside and low-pressure cylinders outside all on the same horizontal plane in line with the smoke-box and all driving the front driving axle. Each cylinder has its own valve but the two valves of each pair of cylinders are worked from a single valve motion of a modified Walschaert type. This arrangement permits the varying of the cut-off of the two cylinders giving different ratios of expansion which cannot, however, be varied by the engine-man. |
