NZASM 40 Tonner 0-6-2T

NZASM 40 Tonner 0-6-2T
CSAR Class A 0-6-2T

40 Tonner no. 50 S.W. Burger, Komatipoort, c. 1895

Type and origin Power type Steam Designer Maschinenfabrik Esslingen Builder Maschinenfabrik Esslingen Serial number Esslingen 2436-2445, 2480-2489 Build date 1891-1892 Total produced 20

Specifications Configuration 0-6-2T (Branchliner) Driver 2nd coupled axle Gauge 3 ft 6 in (1,067 mm) Cape gauge Coupled dia. 51 3⁄16 in (1,300 mm) Trailing dia. 31 1⁄2 in (800 mm) Wheelbase 18 ft 10 3⁄8 in (5,750 mm)  • Coupled 11 ft 1 7⁄8 in (3,400 mm) Wheel spacing (Asymmetrical) 1-2: 5 ft 10 3⁄32 in (1,780 mm) 2-3: 5 ft 3 25⁄32 in (1,620 mm) Length: ​  • Over couplers 33 ft 6 1⁄2 in (10,224 mm) Height 12 ft 4 11⁄32 in (3,768 mm) Frame type Plate Axle load 9.98 LT (10,140 kg)  • Coupled 9.98 LT (10,140 kg)  • Trailing 9 LT 12 cwt (9,754 kg) Adhesive weight 29.94 LT (30,420 kg) Loco weight 39.54 LT (40,170 kg) Fuel type Coal Fuel capacity 2 LT 12 cwt (2.6 t) Water cap 1,525 imp gal (6,930 l) Firebox type Round-top  • Firegrate area 16.4 sq ft (1.52 m2) Boiler: ​  • Pitch 5 ft 9 9⁄32 in (1,760 mm)  • Diameter 3 ft 9 9⁄32 in (1,150 mm)  • Tube plates 12 ft 8 3⁄4 in (3,880 mm)  • Small tubes 144: 1 25⁄32 in (45 mm) Boiler pressure 160 psi (1,103 kPa) Heating surface 946.2 sq ft (87.90 m2)  • Tubes 845 sq ft (78.5 m2)  • Firebox 101.2 sq ft (9.40 m2) Cylinders Two Cylinder size 16 15⁄16 in (430 mm) bore 24 13⁄16 in (630 mm) stroke Valve gear Heusinger Valve type Murdoch's D slide Couplers Johnston link-and-pin

Performance figures Tractive effort 16,707 lbf (74.32 kN) @ 75%

Career Operators NZASM Selati Railway Imperial Military Railways Central South African Railways Class NZASM 40 Tonner CSAR Class A Number in class 20 Numbers NZASM 41-60, CSAR 1-19 Official name 40 Tonner Delivered 1892-1893 First run 1892

The NZASM 40 Tonner 0-6-2T of 1892 was a South African steam locomotive from the pre-Union era in Transvaal.

In 1892 and 1893, the Nederlandsche-Zuid-Afrikaansche Spoorweg-Maatschappij (NZASM) of the Zuid-Afrikaansche Republiek (Transvaal Republic) placed twenty tank locomotives with a 0-6-2 wheel arrangement in mainline service. Since the railway classified its locomotives according to their weight, these locomotives were known as the 40 Tonners.

Although the completion of the line from Delagoa Bay to Pretoria was still more than three years in the future, a requirement for larger and heavier mainline locomotives was identified in 1891. The Nederlandsche-Zuid-Afrikaansche Spoorweg-Maatschappij (NZASM) therefore ordered ten 0-6-2T tank locomotives from Emil Kessler's Maschinenfabrik Esslingen. A second order for another ten followed later in 1891.

The first batch of locomotives were delivered in 1892, numbered in the range from 41 to 50. Of the second batch, numbered in the range from 51 to 60, the last seven were built in 1892. Since the NZASM classified its locomotives according to their weight, these locomotives were known as the 40 Tonners. In addition to being numbered, they were all named as well, with the names and numbers cast in brass and mounted on their tank sides.

The locomotive used Murdoch's D unbalanced slide valves, arranged horizontally above the cylinders outside the plate frames and actuated by Heusinger valve gear. These valves caused considerable wear on motion pins and were later replaced by Trick ported balanced slide valves.

The boiler barrel was built up in three rings, arranged telescopically, with the smallest diameter at the firebox end. The rings were lap-jointed and double riveted on longitudinal seams. These boilers had a long life and required little expense in repairs. Five cross-stays were fitted in the steam space above the firebox. The safety valves were arranged above the firebox inside the cab, while a steam escape pipe was fitted above the valves and passed through the roof.