BHStB Series IIIa4 Locomotive JDZ 189-203

Military Occupation of Bosnia and Herzegovina (Manufactured 1885-1896)

On the curvaceous section between Mostar-Konjic with a gradient up to 10 thousandth the JDŽ 189 (IIIa4) is used. Hauled load was 175 t. Thanks to their Klose steering axles, the tracks with the tight corners were sparing. Manufactured from 1885 to 1896.

The IIla4 series were Klose support tank locomotives with three coupled axles and Klose steering gear in Bosnian gauge of the Bosnian-Herzegovinian State Railways (BHStB, from 1895) and their two predecessors, the Bosnian-Herzegovinian State Railways (BHStB, 1884 to 1895) and the kuk Bosna Railway (kkBB, 1879 to 1895). The Royal Saxon State Railways also procured similar locomotives as Class III K.

For the development of the areas of Bosnia and Herzegovina occupied by Austria from 1878 by decision of the Berlin Congress , narrow-gauge railways with a track width of 760 mm were built, which, due to the difficult terrain, had steep gradients and narrow curves with radii of up to 33 meters. Over time, the two-axle tank locomotives were no longer able to cope with the constantly increasing traffic. The demanding route conditions led to the development and procurement of locomotives with Klose steering axles , which impressed with their good curve travel.

In 1885 the Munich plant of Krauss & Co. developed a three-coupler locomotive with a single-axle support tender for the Bosna Railway. The machine, built in the Austrian Krauss factory in Linz, proved itself and Krauss & Comp. From 1887 to 1896, Linz delivered another 33 identical vehicles to the Bosna Railway and the BHStB.

Technical Features

The machines had an outer frame and inner cylinder with external valve boxes for the Stephenson controls . The first and third coupled axles were radially adjusted via the support tender, which also carried the coal bunker. The water supplies were recorded in lateral boxes.

The two outer of the three coupled axles were designed as Klose steering axles. They were adjusted radially via lever work by the movements of the uniaxial Klose support tender , which rotated about a pivot in front of the firebox . This resulted in a good ability to curve (contemporary curve ability) of the locomotive. The lengthening and shortening of the coupling rod caused by the radial adjustment of the two outer wheel sets was carried out via a so-called differential head. It was located above the middle coupled axle and was equipped with a parallelogram linkage with the axle bearings connected to the steering axles. Depending on the rotation of the steering axles, the angle of the differential head changed, resulting in the right length of the coupling rod.

Despite the multi-part drive and running gear, the locomotives have proven themselves so that further locomotives with Klose steering axles were ordered.

Manufacturer:

Locomotive factory Krauss & Comp. Linz

Years Manufactured:

1885-1896

Type :

 C1't

Gauge :

 760 mm ( Bosnian Gauge )

Length Over Coupling:

 9,234m

Overall Wheelbase:

 6 m

Service Mass:

 25.6 tons

Friction Mass:

 19.2t

Top Speed:

 50km/h

Starting Traction:

 49kN

Coupling Wheel Diameter:

 900mm

impeller Diameter:

 650mm

Cylinder Diameter:

 290mm

Piston Stroke:

 450mm

Boiler Overpressure:

 12 atm

Grate Surface:

 0.9 m²

Evaporation Heating Surface:

 58.2 sqm

Tender:

 Support Tender

water supply:

 2.7m³

fuel supply:

 2 Tons