NZASM 40 Tonner 0-6-2T

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.^[1][2]

Manufacturer

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.^[1][3]

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.^[1]

Characteristics

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.^[1][2]

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.^[2]

The exhaust had an Adams' Vortex pattern annular nozzle. While this presented additional surface to the blast, the annular orifice had a tendency to become clogged, which increased back pressure, and the exhaust pipes therefore frequently had to be taken out for cleaning. As delivered, the locomotive had 5 inches (127 millimetres) thick wooden buffer beams which were later replaced by 1 inch (25 millimetres) thick steel plates.^[2]

The distance between the locomotive's tyres, i.e. between the wheel flanges on the axle, was 3 feet 3 ³⁄₈ inches (1,000 millimetres). This was ³⁄₈ inch (10 millimetres) greater than for engines of the Cape Government Railways and Natal Government Railways and, although the flanges were somewhat thinner, the resulting tightness to gauge was blamed for the rather high rate of flange wear. To obtain greater life from the leading coupled wheels, they were occasionally exchanged with the trailing coupled wheels during overhauls.^[2]

The original coupled axles were 5 ¹⁄₄ inches (133 millimetres) in diameter and were inclined to fracture. This was remedied by increasing the diameter to 5 ³⁄₄ inches (146 millimetres) on new axles. The trailing wheels also proved to be troublesome. The trailing wheels and axle were of the radial type and were attached directly to the frame, which gave the locomotive a rigid wheelbase. The problem arose as a result of insufficient sideward freedom of movement of the trailing axle when the locomotive traversed sharp curves and diverging points.^[1][2]

Service

NZASM

The 40 Tonners were found to be satisfactory in service, but the absence of leading carrying wheels resulted in a rough ride.^[1]

Selati Railway

In June 1890, Eugene, the younger of the Barons Oppenheim, sought to obtain a concession from the Government of the Zuid-Afrikaansche Republiek to construct a railway line to the Murchison Range goldfields along the Selati River. Work on the construction of the Selati Railway in the Transvaal Lowveld began early in 1893, with the line branching off from the Pretoria-Delagoa Bay mainline at a junction near Komatipoort. The two locomotives Durban and Pietermaritzburg were purchased from the Natal Government Railways for use during construction, as well as two 40 Tonners which were acquired from the NZASM.^[1][4]

The project was abandoned in 1894, due to financial difficulties as well as a dispute which arose with the NZASM over the chosen route. Work on the railway was only resumed and completed by the Central South African Railways (CSAR) in 1909. The line was then extended via Gravelotte and Tzaneen to a junction at Soekmekaar, where it met the line from Pietersburg to Messina in 1912. In 1963, the part of the line through the southern part of the Kruger National Park, from the junction near Komatipoort, was abandoned and replaced by a new line from the present junction near Kaapmuiden.^[1][4][5]

Imperial Military Railways

In 1899, during the Second Boer War, all railway operations in the two Boer Republics, the ZAR and the Orange Free State, were taken over by the Imperial Military Railways (IMR). Nineteen of the 40 Tonners survived the war.^[1][3]

Central South African Railways

At the end of the war, when the IMR was transformed into the CSAR, the nineteen surviving 40 Tonners were designated Class A and renumbered in the range from 1 to 19. None survived in railway service to be taken onto the South African Railways roster in 1912.^[1][6]

Works numbers

The 40 Tonner engine numbers, names, works numbers and years built are listed in the table.^[1]

Illustration

The main picture shows no. 50, the S.W. Burger, on a mixed train at Komatipoort. The picture of the same engine below offers a side view of the 40 Tonner locomotive.

The second picture below offers an overhead view of a 40 Tonner, either no. 55 Van Riebeeck or no. 57 Pretorius, after the Braamfontein disaster of 1896. One of the worst explosions in the history of South Africa occurred at Braamfontein station, Johannesburg, on 19 February 1896. An explosives train carrying between 56 and 60 tons of dynamite, which had been standing in searing heat for 3½ days, was struck by a shunting train and exploded. The blast left a crater 60 metres (197 feet) long, 50 metres (164 feet) wide and 8 metres (26 feet) deep and was heard in Klerksdorp, 200 kilometres (124 miles) away. The exact number of casualties was never ascertained, but at least 62 people were killed and more than 200 seriously injured. Surrounding suburbs as far as Fordsburg were partially destroyed. Some 3,000 people lost their homes and almost every window in the town was shattered.^[7]

• 
  No. 50 S.W. Burger, c. 1895
• 
  40 Tonner being recovered at Braamfontein, 20 February 1896

References

Wikimedia Commons has media related to NZASM 40 Tonner 0-6-2T.

Locomotives of the Central South African Railways
3' 6" gauge	CSAR 0-6-0ST 1896 CSAR 4-6-0T 1887 CSAR Class 6-L1 CSAR Class 6-L2 CSAR Class 6-L3 CSAR Class 7 CSAR Class 8-L1 CSAR Class 8-L2 CSAR Class 8-L3 CSAR Class 9 CSAR Class 10 1904 CSAR Class 10 1910 CSAR Class 10-2 Saturated CSAR Class 10-2 Superheated CSAR Class 10-C CSAR Class 11 CSAR Class B 0-6-4T CSAR Class C 2-8-4T CSAR Class D CSAR Class E 4-8-0TT CSAR Class E 4-8-2T CSAR Class E 4-10-2T CSAR Class F CSAR Class M CSAR Mallet Saturated CSAR Mallet Stoker CSAR Mallet Superheated CSAR Rack 4-6-4RT CSAR Railmotor IMR 0-6-0ST 1896 IMR 4-6-0T 1887 IMR 46 Tonner 0-6-4T IMR 55 Tonner 2-6-4T IMR 7th Class 4-8-0 IMR 8th Class 4-8-0 IMR Reid Tenwheeler 4-10-2T IMR Western Australian 2-8-4T NZASM 10 Tonner NZASM 13 Tonner NZASM 14 Tonner NZASM 18 Tonner NZASM 19 Tonner NZASM 32 Tonner NZASM 40 Tonner NZASM 46 Tonner OVGS 1st Class 4-4-0TT OVGS 2nd Class 2-6-0 OVGS 2nd Class 2-6-0ST OVGS 3rd Class 4-4-0 OVGS 4th Class G 4-6-0 OVGS 5th Class K 4-6-0 1890 OVGS 5th Class K 4-6-0 1891 OVGS 6th Class L 4-6-0 OVGS 6th Class L2 4-6-0 OVGS 6th Class L3 4-6-0 PPR 0-4-0ST Natal PPR 26 Tonner PPR 35 Tonner Portuguese PPR 55 Tonner
2' gauge	CSAR Pankop
List of South African locomotive classes South African locomotive history

Locomotives of South Africa
Steam	7' ¼" gauge East London 0-4-0VB Table Bay 0-4-0ST Table Bay 0-4-0T Table Bay 0-4-0WT 4' 8½" gauge Cape 0-4-0T Blackie Cape 0-4-2 Cape 2-4-0T CGR 0-4-0ST Aid Natal 0-4-0ST Durban Natal 0-4-0WT Natal Natal 4-4-0T Perseverance 3' 6" gauge Tank engines CGR 0-4-0ST 1873 CGR 0-4-0ST 1874 CGR 0-4-0ST 1881 CGR 0-4-0ST 1881 Coffee Pot CGR 0-6-0ST CGR 0-6-0T CGR 2-6-0ST 1900 CGR 2-6-0ST 1902 CGR 1st Class 0-4-0ST 1875 CGR 1st Class 0-4-0ST 1876 CGR 1st Class 2-6-0ST CGR 1st Class 4-4-0T CGR 2nd Class 4-4-0T CGR 3rd Class 2-6-0T CGR Railmotor CSAR Class C CSAR Class E CSAR Rack 4-6-4RT CSAR Railmotor Durban's Congella Durban's Edward Innes Durban's John Milne Durban's Sir Albert Port Elizabeth 0-4-0ST Kowie Railway 0-6-0T Kowie Railway 4-4-0T Metropolitan & Suburban 4-6-2T NGR 2-6-0T Durban & Pietermaritzburg NGR Class I 2-6-2T NGR Class K 0-4-0ST NGR Class K 0-6-0ST NGR Class K 2-6-0T NZASM 10 Tonner NZASM 13 Tonner NZASM 14 Tonner NZASM 18 Tonner NZASM 19 Tonner NZASM 32 Tonner NZASM 40 Tonner PPR 26 Tonner PPR 35 Tonner Portuguese SAR Class A SAR Class B SAR Class C SAR Class C1 SAR Class C2 SAR Class D SAR Class E SAR Class F SAR Class G SAR Class H SAR Class H1 SAR Class H2 SAR Class J SAR Class K SAR Railmotor SAR Dock 0-4-0ST SAR Dock 0-4-0T SWA 2-8-0T 3' 6" gauge Tender engines CGR 1st Class 2-6-0 1876 BP CGR 1st Class 2-6-0 1876 Kitson CGR 1st Class 2-6-0 1879 CGR 1st Class 2-6-0 1891 CGR 1st Class 4-4-0 CGR 1st Class 4-4-0TT CGR 2nd Class 2-6-2TT CGR 3rd Class 4-4-0 1883 CGR 3rd Class 4-4-0 1884 CGR 3rd Class 4-4-0 1889 CGR 3rd Class 4-4-0 1898 CGR 3rd Class 4-4-0 1901 CGR 3rd Class 4-4-0 1903 CGR 4th Class 4-4-2 CGR 4th Class 4-6-0TT 1880 CGR 4th Class 4-6-0TT 1882 CGR 4th Class 4-6-0TT 1882 Joy CGR 4th Class 4-6-0TT 1884 CGR 5th Class 4-6-0 1890 CGR 5th Class 4-6-0 1891 NGR Havelock NGR Class I SAR Class Exp 1 SAR Class Exp 2 SAR Class Exp 3 SAR Class Exp 4 SAR Class Exp 5 SAR Class Exp 6 SAR Class S SAR Class S1 SAR Class S2 SAR Class 1 SAR Class 1A SAR Class 1B SAR Class 2 SAR Class 2C SAR Class 3 SAR Class 3A SAR Class 3B SAR Class 4 SAR Class 4A SAR Class 5 SAR Class 5A SAR Class 5B SAR Class 6 SAR Class 6A SAR Class 6B SAR Class 6C SAR Class 6D SAR Class 6E SAR Class 6F SAR Class 6G SAR Class 6H SAR Class 6J SAR Class 6K SAR Class 6L SAR Class 6Y SAR Class 6Z SAR Class 7 SAR Class 7A SAR Class 7B SAR Class 7C SAR Class 7D SAR Class 7E SAR Class 7F SAR Class 8 SAR Class 8A SAR Class 8B SAR Class 8C SAR Class 8D SAR Class 8E SAR Class 8F SAR Class 8R SAR Class 8X SAR Class 8Y SAR Class 8Z SAR Class 9 SAR Class 10 SAR Class 10A SAR Class 10B SAR Class 10C SAR Class 10D SAR Class 11 SAR Class 12 SAR Class 12A SAR Class 12B SAR Class 13 SAR Class 14 SAR Class 14A SAR Class 14B SAR Class 14C 1st SAR Class 14C 2nd SAR Class 14C 3rd SAR Class 14C 4th SAR Class 15 SAR Class 15A SAR Class 15B SAR Class 15C SAR Class 15CA SAR Class 15E SAR Class 15F SAR Class 16 SAR Class 16A SAR Class 16B SAR Class 16C SAR Class 16D SAR Class 16DA 1928 SAR Class 16DA 1930 SAR Class 16E SAR Class 17 SAR Class 18 SAR Class 19 SAR Class 19A SAR Class 19B SAR Class 19C SAR Class 19D SAR Class 20 SAR Class 21 SAR Class 23 SAR Class 24 SAR Class 25 SAR Class 25NC SAR Class 26 SAR Katanga SWA 2-8-0 3' 6" gauge Articulated engines CGR Fairlie CGR Kitson-Meyer SAR Class FC SAR Class FD SAR Class GA SAR Class GB SAR Class GC SAR Class GCA SAR Class GD SAR Class GDA SAR Class GE SAR Class GEA SAR Class GF SAR Class GG SAR Class GH SAR Class GK SAR Class GL SAR Class GM SAR Class GMA SAR Class GO SAR Class HF SAR Class KM SAR Class MA SAR Class MB SAR Class MC SAR Class MC1 SAR Class MD SAR Class ME SAR Class MF SAR Class MG SAR Class MH SAR Class MJ SAR Class MJ1 SAR Class U 2' 6" gauge Cape Copper John King & Miner Cape Copper Britannia Cape Copper Caledonia Cape Copper Clara Cape Copper Condenser Cape Copper Scotia Namaqua Copper Pioneer Walvis Bay 2-4-2T Hope 2' & 600mm gauges ACR Class NG-G16A CGR NG 0-4-0T CGR NG 0-6-0T CGR NG 4-6-2T CGR Type A 2-6-4T CGR Type C 0-4-0T NGR Class N 4-6-2T SAR Dutton SAR NG 0-4-0T SAR Class NG1 SAR Class NG2 SAR Class NG3 SAR Class NG4 SAR Class NG5 SAR Class NG6 SAR Class NG7 SAR Class NG8 SAR Class NG9 SAR Class NG10 SAR Class NG-G11 SAR Class NG-G12 SAR Class NG-G13 SAR Class NG-G14 SAR Class NG15 SAR Class NG-G16 SWA Class Ha SWA Class Hb SWA Class Hc SWA Class Hd SWA Jung SWA Zwillinge
Electric	Amcoal Class E38 SAR Class ES SAR Class ES1 SAR Class Exp-AC SAR Class 1E SAR Class 2E SAR Class 3E SAR Class 4E SAR Class 5E s1 SAR Class 5E s2 SAR Class 5E s3 SAR Class 5E1 s1 SAR Class 5E1 s2 SAR Class 5E1 s3 SAR Class 5E1 s4 SAR Class 5E1 s5 SAR Class 6E SAR Class 6E1 s1 SAR Class 6E1 s2 SAR Class 6E1 s3 SAR Class 6E1 s4 SAR Class 6E1 s5 SAR Class 6E1 s6 SAR Class 6E1 s7 SAR Class 6E1 s8 SAR Class 6E1 s9 SAR Class 6E1 s10 SAR Class 6E1 s11 SAR Class 7E SAR Class 7E1 SAR Class 7E2 s1 SAR Class 7E2 s2 SAR Class 7E3 s1 SAR Class 7E3 s2 Spoornet Class 7E4 SAR Class 8E SAR Class 9E s1 SAR Class 9E s2 SAR Class 10E SAR Class 10E1 s1 Spoornet Class 10E1 s2 SAR Class 10E2 SAR Class 11E SAR Class 12E Spoornet Class 14E Spoornet Class 14E1 TFR Class 15E Spoornet Class 16E Spoornet Class 17E Spoornet Class 18E s1 TFR Class 18E s2 TFR Class 19E TFR Class 20E TFR Class 21E TFR Class 22E
Gas-electric	SAR Gas-electric
Diesel	3' 6" gauge Diesel-electric PRASA Class Afro 4000 SAR Class DS SAR Class DS1 SAR Class 31-000 SAR Class 32-000 SAR Class 32-200 SAR Class 33-000 SAR Class 33-200 SAR Class 33-400 SAR Class 34-000 SAR Class 34-200 SAR Class 34-400 SAR Class 34-500 SAR Class 34-600 SAR Class 34-800 SAR Class 34-900 SAR Class 35-000 SAR Class 35-200 SAR Class 35-400 SAR Class 35-600 TFR Class 35-800 SAR Class 36-000 SAR Class 36-200 SAR Class 37-000 Spoornet Class 39-000 TFR Class 39-200 TFR Class 43-000 TFR Class 44-000 2' gauge Diesel-electric SAR Class 91-000 3' 6" gauge Diesel-hydraulic SAR Class 61-000 3' 6" gauge Electro-diesel Spoornet Class 38-000
List of South African locomotive classes South African locomotive numbering and classification