Military Occupation of Bosnia and Herzegovina (Manufactured 1907-1913)
The IIIb5 series were superheated steam locomotives with three coupled axles and two-axle tenders in Bosnian gauge , procured from 1907 to 1913 by the Bosnian-Herzegovinian State Railways (BHStB). On the Yugoslav Railways (JDŽ, later JŽ) it was designated as the 73 series. BHStB Series IIIb5 Loco JDZ 73 manufactured from 1907-1913.
Build between 1907–1913 by Krauss Linz, MÁVAG. One exemplar is a museum piece in Jablanica within the WW2 Monument for the "Battle of Neretva"
In the early years of the 20th century, technical advances overtook the complicated Klose construction used on the IIIa4 and IIa4 series . The development of the Krauss-Helmholtz steering frame in connection with laterally displaceable coupled axles made it possible to build steam locomotives that were coupled several times and could still curve well. In 1907, Krauss in Linz designed the Class IIIb5 tender locomotives with Schmidt superheaters after the Class Mh was used as a superheated steam locomotive on the Lower Austrian state railwayshad proven good. Because of the joint administration by the Austrian and Hungarian halves of Bosnia-Herzegovina, 15 machines came from the Krauss plant in Linz and the other 8 from the Budapest machine works (MÁVAG).
Three locomotives have survived: JŽ 73-002, JDŽ 73-018, and JDŽ 73-019
Technical Features
The prairie locomotives with external frames and a wide firebox are each guided by a Krauss-Helmholtz frame at the front and rear. The drive takes place on the middle wheel flangeless coupled axle. Like the older Klose machines, the IIIb5 series does not have a fixed wheelbase, but a large guided length. With this chassis, the locomotive is suitable for radii of up to 50 meters. It is driven by Hall cranks and controlled by the Heusinger system . The cylinders are with piston valvesfitted. With the largest driving wheel diameter on the Bosnian-Herzegovinian State Railways of 1100 millimeters, the express train reached a speed of 60 km/h, which was impressive for the time with a standard speed of 35 km/h. The locomotives are equipped with Gresham type vacuum brakes and a handbrake . The individual locomotives differed in the arrangement of the sand boxes, some machines were equipped with a Kobel spark arrestor .
Above: Connecting rod and Heusinger control acting on piston slide.
Number Built:
23
Manufacturer:
Krauss Linz , MÁVAG
Year(s):
1907-1913
Type :
1'C1'h2
Gauge :
760 mm ( Bosnian Gauge )
Length over coupling:
13.129m
Overall Wheelbase:
11.150m
Service Mass:
30.6 tons
Friction Mass:
20.6t
Top Speed:
55km/h
Indexed Performance :
360 hp
Starting Traction:
40kN
Coupling Wheel Diameter:
1100mm
impeller Diameter:
640mm (rear)
Cylinder Diameter:
370mm
Piston Stroke:
450mm
Boiler Overpressure:
12 atm
Grate Surface:
1.54 m²
Evaporation Heating Surface:
91.95 m²
Tender:
Towed Tender
Water Supply:
5.5m³
Fuel supply:
3 Tons
Train on the Bosna Railway with a JDŽ 73 and a reversing JDŽ 189 as the lead locomotive
Above: JŽ 73-015 in front of the boiler house in Prijedor in August 1967
Above: Train of the Steinbeisbahn in Prijedor with JŽ 73-008 ready to depart
