Serbian State Articulated Locomotives in Serbia


Class Details by Steve Llanso of Sweat House Media

Class 391 / U47 / 90 (Locobase 5852)

Data from [link] and from a Czech-language website,

This little B'B' Mallet design had the LP cylinder leading, HP driving the rear set.

All were originally delivered to the Serbian State in two main batches. Henschel & Sohn produced 2 (works numbers 7930-7931) for the Donja Cupria- Senjski Rudnik narrow-gauge coal line. Four years later, Hohenzollern secured an order for 10 more (works numbers 2787-2796) for similar work.

Five of the twelve were commandeered by the German Army during World War One while others wound up in Czechoslovakia. At the end of the war, the new JDZ (Yugoslav State) retained 8 (SHS 13001-13008), which it dubbed the 90 class in 1933.

The Czech engines were reclassified U47 and numbered 001-004.


Class 91 (Locobase 2897)

Data from Durrant's The Mallet Locomotive, as reproduced on narrowmind.railfan.net and from Wiener (1930). See also A[nthony] E[dward] Durrant, The Steam Locomotives of Eastern Europe (Newton Abbot:David & Charles, 1966), pp. 131. Borsig works numbers were 8491-8495 in 1913. Henschel followed with 14184-14227 in 1916.

This Mallet tank was described by Durrant as the "final and the best CDZ [Serbian railways] narrow-gauge power". Wiener gives their tonnage rating as 180 tons at 9 1/2 mph up 2% grades and around curves with a 197-ft radius. Small-drivered, these engines had both engine sets moved back as far as possible along the frame to reduce the total wheelbase, according to Wiener. The water tanks extended from the cab to just short of the smokebox. The leading coupled axle was carried in a Krauss-Helmholz bogie with the leading truck.

Four survivors later renumbered in Yugoslavia as 91.035-038. By this time, their weights had gone up. Also, Durrant's 1966 book on Eastern European railways shows a smaller diameter for the LP cylinders (500 mm or 19.68 in), but a larger grate (2.17 sq m or 23.35 sq ft). This may represent a later modification.


Class 92 (Locobase 3611)

Data from Wiener (1930); and A[nthony] E[dward] Durrant, The Steam Locomotives of Eastern Europe (Newton Abbot:David & Charles, 1966), pp. 131. Works numbers 15581-15600 in 1917, 19458-19487 in 1922.

Durrant wrote these engines used "a remarkable design for so narrow a gauge ...[they] were larger and more powerful than some major British standard-gauge railways then possessed!" (exclamation in the original). He added that linking the Bosnian and Serbian sections of 76 cm rail created a continuous route from Beograd (Belgrade) through Sarajevo and down to Dubrovnik. The 92s "were ideal for the heavy freight, particularly the Sarajevo-Beograd stretch". They surmounted a "high range of mountains and from Visegrad eastwards a series of loops and spirals were built to gain height." Here, the 92s gained assistance from the earlier 91 class 2-6-6-0Ts (Locobase 2897) as bankers (helpers).

Their usefulness evaporated once the main lines were widened to standard gauge after World War Two and the engines were scrapped.

Principal Dimensions by Steve Llanso of Middle Run Media
Class391 / U47 / 909192
Locobase ID5852 2897 3611
RailroadSerbian State (JDZ)Serbian State (JDZ)Serbian State (JDZ)
CountrySerbiaSerbiaSerbia
Whyte0-4-4-0T2-6-6-0T2-6-6-0
Number in Class1250
Road Numbers391-402 /501-505, 6002-6045/91.001-03892.001-049
Gauge76 cm76 cm76 cm
Number Built1250
BuilderseveralseveralHenschel & Sohn
Year190619131917
Valve GearHeusingerWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m) 3.77 / 1.15 6.56 / 2 6.56 / 2
Engine Wheelbase (ft / m)13.12 / 425.66 / 7.8225.59 / 7.80
Ratio of driving wheelbase to overall engine wheelbase 0.29 0.26 0.26
Overall Wheelbase (engine & tender) (ft / m)50.43 / 15.37
Axle Loading (Maximum Weight per Axle) (lbs / kg)15,432 / 7000
Weight on Drivers (lbs / kg)59,525 / 27,000101,025 / 45,824107,297 / 48,669
Engine Weight (lbs / kg)59,525 / 27,000114,016 / 51,717121,184 / 54,968
Tender Loaded Weight (lbs / kg)72,689 / 32,971
Total Engine and Tender Weight (lbs / kg)59,525 / 27,000114,016 / 51,717193,873 / 87,939
Tender Water Capacity (gals / ML)924 / 3.5013,200 / 502199 / 8.33
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 2.30 / 2 2.20 / 25 / 5
Minimum weight of rail (calculated) (lb/yd / kg/m)25 / 12.5028 / 1430 / 15
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)31.50 / 80031.50 / 80031.50 / 800
Boiler Pressure (psi / kPa)203.10 / 1400185.60 / 1280203.10 / 1400
High Pressure Cylinders (dia x stroke) (in / mm)9.45" x 15.75" / 240x40012.99" x 15.75" / 330x40014.57" x 15.75" / 370x400
Low Pressure Cylinders (dia x stroke) (in / mm)14.57" x 15.75" / 370x40020.51" x 15.75" / 521x40022.05" x 15.75" / 560x400
Tractive Effort (lbs / kg)10,852 / 4922.3918,999 / 8617.8125,510 / 11571.16
Factor of Adhesion (Weight on Drivers/Tractive Effort) 5.49 5.32 4.21
Heating Ability
Tubes (number - dia) (in / mm)181 - 1.732" / 4479 - 1.811" / 46
Flues (number - dia) (in / mm)18 - 5.236" / 133
Flue/Tube length (ft / m)13.12 / 416.40 / 5
Firebox Area (sq ft / m2)50.36 / 4.6868.89 / 6.4099.96 / 9.29
Grate Area (sq ft / m2)10.01 / 0.9320.45 / 1.9032.39 / 3.01
Evaporative Heating Surface (sq ft / m2)554 / 51.501171 / 108.801085 / 100.84
Superheating Surface (sq ft / m2)430 / 40
Combined Heating Surface (sq ft / m2)554 / 51.501171 / 108.801515 / 140.84
Evaporative Heating Surface/Cylinder Volume433.30484.71356.99
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation203337966578
Same as above plus superheater percentage203337968420
Same as above but substitute firebox area for grate area10,22812,78625,986
Power L1282724528356
Power MT418.81321.051030.14

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