Württemberg T 4

The Württemberg T 4 was a class of German, eight-coupled, goods train, tank locomotive operated by the Royal Württemberg State Railways.

Württemberg T 4 DRG Class 92.1
T4 No. 852 works photo, 1906
Number(s)	Nr. 851–858 DRG 92 101–92 108
Quantity	8
Manufacturer	Maschinenfabrik Esslingen
Year(s) of manufacture	1906 and 1909
Retired	by 1948
Wheel arrangement	0-8-0T
Axle arrangement	D n2t
Type	Gt 44.16
Track gauge	1,435 mm (4 ft 8 1⁄2 in)
Length over buffers	11,000 mm (36 ft 1 in)
Height	4,650 mm (15 ft 3 in)
Wheelbase	4,650 mm (15 ft 3 in)
Overall wheelbase	4,650 mm (15 ft 3 in)
Empty weight	49.80 tonnes (49.01 long tons; 54.90 short tons)
Service weight	64.50 tonnes (63.48 long tons; 71.10 short tons)
Adhesive weight	64.50 tonnes (63.48 long tons; 71.10 short tons)
Axle load	16.10 tonnes (15.85 long tons; 17.75 short tons)
Top speed	52 km/h (32 mph)
Driving wheel diameter	1,380 mm (4 ft 6 3⁄8 in)
Valve gear	Walschaerts (Heusinger)
No. of cylinders	2
Cylinder bore	530 mm (20 7⁄8 in)
Piston stroke	612 mm (24 1⁄8 in)
Boiler Overpressure	14.0 kg/cm2 (1.37 MPa; 199 psi)
No. of heating tubes	266
Heating tube length	4,000 mm (13 ft 1 1⁄2 in)
Grate area	2.08 m2 (22.4 sq ft)
Radiative heating area	9.70 m2 (104.4 sq ft)
Tube heating area	133.70 m2 (1,439.1 sq ft)
Evaporative heating area	143.40 m2 (1,543.5 sq ft)
Water capacity	6.00 m3
Fuel	1.50 t coal
Locomotive brakes	Screw brake, counterpressure brake

When the T 3 locomotives were no longer capable of banking services on the Geislinger Steige, a locomotive was designed that was to develop twice the power. Because no more locomotives were needed for duties on the ramps, only eight were produced, of which five were supplied in 1906 and three in 1909. In their day they were the heaviest eight-coupled locomotives in Germany.

In designing the boiler, special emphasis had been laid on a large steam space and a low-lying firebox crown so that banking could be achieved with refilling with water, which led to a reduction in boiler pressure and a resultant drop in performance.

In order to reduce wear and tear on the tyres and brake shoes during descents, the engines were fitted with Riggenbach counter-pressure brakes.

In 1925 the Deutsche Reichsbahn took over all eight locomotives and grouped them into DRG Class 92.1 in their numbering plan. After the Second World War they ended up in the Deutsche Bundesbahn, where they were retired between 1946 and 1948 or sold as industrial locomotives.