The NZASM 13 Tonner 0-4-0T of 1889 was a South African steam locomotive from the pre-

Union Union commonly refers to: * Trade union, an organization of workers * Union (set theory), in mathematics, a fundamental operation on sets Union may also refer to: Arts and entertainment Music * Union (band), an American rock group ** ''Un ...

era in the

Transvaal Transvaal is a historical geographic term associated with land north of (''i.e.'', beyond) the Vaal River in South Africa. A number of states and administrative divisions have carried the name Transvaal. * South African Republic (1856–1902; af, ...

. In 1889, the '' Nederlandsche-Zuid-Afrikaansche Spoorweg-Maatschappij'' acquired a single locomotive, very similar to its 14 Tonner locomotives and built by the same manufacturer, but with a smaller water and coal capacity. Since the railway classified its locomotives according to their weight, this well-and-side-tank locomotive was known as the 13 Tonner.Espitalier, T.J.; Day, W.A.J. (1944). ''The Locomotive in South Africa - A Brief History of Railway Development. Chapter IV - The N.Z.A.S.M.''. South African Railways and Harbours Magazine, October 1944. pp. 761-764.

The Randtram line

As a result of the rapid development of the goldfields on the

Witwatersrand The Witwatersrand () (locally the Rand or, less commonly, the Reef) is a , north-facing scarp in South Africa. It consists of a hard, erosion-resistant quartzite metamorphic rock, over which several north-flowing rivers form waterfalls, which ...

in the 1880s and the demand for coal by the growing industry, the ' of the ' (ZAR), also known as the Transvaal Republic, granted a concession to the ''Nederlandsche-Zuid-Afrikaansche Spoorwegmaatschappij'' (Netherlands-South African Railway Company, NZASM) on 20 July 1888 to construct a railway from

Johannesburg Johannesburg ( , , ; Zulu and xh, eGoli ), colloquially known as Jozi, Joburg, or "The City of Gold", is the largest city in South Africa, classified as a megacity, and is one of the 100 largest urban areas in the world. According to Demo ...

Boksburg Boksburg is a city on the East Rand of Gauteng province of South Africa. Gold was discovered in Boksburg in 1887. Boksburg was named after the State Secretary of the South African Republic, W. Eduard Bok. The Main Reef Road linked Boksburg ...

. The railway, which was opened on 17 March 1890, became known as the Randtram line.The South African Railways - Historical Survey. Editor George Hart, Publisher Bill Hart, Sponsored by Dorbyl Ltd., Published c. 1978, p. 19.

Manufacturer

In 1889, six small locomotives were delivered to the NZASM by the German engineering firm and locomotive builder Maschinenfabrik Esslingen, owned by Emil Kessler. Five of these were the NZASM 14 Tonners. The sixth, the sole 13 Tonner, was also a well-and-side-tank locomotive with a 0-4-0T wheel arrangement and was similar to, but lighter than the 14 Tonner.

Characteristics

The engine's cylinders were arranged outside the plate frames. The "D" type slide valves, mounted above the cylinders, were arranged at an incline and were actuated by Allan straight link motion. In this type of valve gear, the valve rod and the expansion link are respectively connected to opposing arms on the reversing shaft, so that partial rotation of the shaft moves the link and the die block in opposite directions. Apart from the side-tanks, the locomotive also had a well-tank between the frames under the boiler barrel. The dome was on the front section of the boiler and the regulator valve was arranged in the smokebox.

Comparison

Compared to the 14 Tonner, the 13 Tonner differed in at least three respects, judging from photographs. The 13 Tonner had a much narrower coal bunker and a shorter chimney. The side-tanks were also much smaller, reaching only as far forward as aft of the boiler-mounted sandbox dome. On the 14 Tonner, the side-tanks on each side were in two parts and reached as far forward as aft of the steam dome. In addition, the 14 Tonner had two small panels in the side of the rear tank on its right side. The 13 Tonner had no such panels.

References

{{Locomotives of South Africa 0780 0780 B locomotives 0-4-0T locomotives Esslingen locomotives Cape gauge railway locomotives Railway locomotives introduced in 1889 1889 in South Africa