South African Class 12A 4-8-2 - AbsoluteAstronomy.com

Between 1919 and 1929 the South African Railways placed sixty-seven Class 12A steam locomotive

Steam locomotive

A steam locomotive is a railway locomotive that produces its power through a steam engine. These locomotives are fueled by burning some combustible material, usually coal, wood or oil, to produce steam in a boiler, which drives the steam engine...

s with a 4-8-2

4-8-2

Under the Whyte notation for the classification of steam locomotives, 4-8-2 represents the wheel arrangement of four leading wheels on two axles , eight powered and coupled driving wheels on four axles, and two trailing wheels on one axle...

Mountain wheel arrangement in service.

Manufacturers

The Class 12A was the final locomotive design by D.A. Hendrie, Chief Mechanical Engineer (CME) of the South African Railways (SAR) from 1910 to 1922, and one of his finest. It was an improved and larger version of his Class 12

South African Class 12 4-8-2

Between April 1912 and 1922 the South African Railways placed altogether forty-six Class 12 steam locomotives with a 4-8-2 Mountain wheel arrangement in goods train service.-Manufacturers:...

locomotive, with larger diameter cylinders to improve tractive effort and a redesigned boiler that included a combustion chamber. The locomotives were superheated and had Walschaerts valve gear and Belpaire firebox

Belpaire firebox

The Belpaire firebox is a type of firebox used on steam locomotives. It was invented by Alfred Belpaire of Belgium. It has a greater surface area at the top of the firebox, improving heat transfer and steam production...

es.

Between 1919 and 1929 altogether sixty-seven of them were built on five orders, forty-eight by the North British Locomotive Company

North British Locomotive Company

The North British Locomotive Company was created in 1903 through the merger of three Glasgow locomotive manufacturing companies; Sharp Stewart and Company , Neilson, Reid and Company and Dübs and Company , creating the largest locomotive manufacturing company in Europe.Its main factories were...

(NBL) in Scotland and nineteen by Henschel and Son

Henschel & Son

Henschel & Son was a German company, situated in Kassel, best known during the 20th century as a maker of transportation equipment, including locomotives, trucks, buses and trolleybuses, and armoured fighting vehicles and weapons....

in Kassel, Germany. Their works numbers are set out in the table below.

The first twenty were built by NBL and were delivered in 1919, numbered 1520 to 1539.
These were followed by another fifteen from NBL that were built in late 1919 but that were only delivered in 1921, numbered 2111 to 2125.
The Henschel built locomotives only arrived several years later. Six were delivered in 1928 and numbered 1540 to 1545.
Another thirteen were delivered by Henschel in 1929, numbered 1546 to 1550 and 2103 to 2110, filling the gaps in the numbering sequence.
The final thirteen, once again built by NBL, were also delivered in 1929 and numbered 2126 to 2138.

Watson Standard boilers

During the 1930s many serving locomotives were reboilered with a standard boiler type designed by then CME A.G. Watson as part of his standardisation policy. In the process they were then also equipped with Watson cabs, with their distinctive slanted fronts, compared to the conventional vertical fronts of the original cabs. Such Watson Standard reboilered locomotives were reclassified by adding an "R" suffix to their classification.

Loubser’s 12AR boiler

When Class 12A locomotives numbers 1540 and 2135 became the first to be reboilered in 1943, however, none of the Watson Standard boilers were deemed suitable for these locomotives and a special boiler was designed for them by Doctor M.M. Loubser, the CME at the time. The boilers did not conform to any of the Watson Standard boilers and were a totally new type of rather massive proportions that, on a locomotive with relatively small drivers, created an impression of great power. Certain features common to the Watson Standard boilers were retained, however.

Initial and in service repair cost considerations led to these boilers being built without combustion chambers, and the reboilered locomotives were considered by some crews to be inferior steamers when compared with the unreboilered locomotives. A shortened version of Loubser’s Class 12AR boiler was later used on the new Class S1

South African Class S1 0-8-0

In 1947 the South African Railways placed twelve Class S1 shunter steam locomotives with a 0-8-0 wheel arrangement in service, built in the Salt River workshops in Cape Town...

shunting locomotives.

Altogether forty-four Class 12A locomotives were eventually reboilered and reclassified to Class 12AR. During the reboilering, which included the installation of Watson cabs, the locomotives were also equipped with a longer smokebox that resulted in the distinctive appearance of the Class 12AR. Like the Watson Standard boilers, the Loubser boilers also have the visual distinction of the rectangular regulator cover just to the rear of the chimney. In the case of the Class 12AR locomotives three even more obvious visual differences are the extended smokebox, the Watson cab and the absence of the Belpaire firebox hump between the cab and boiler on the reboilered locomotives.

The builders, years built, works numbers and reboilering particulars are set out in the table.

Class 12A 4-8-2
Builders, works numbers and reboilering
Builder	Year built	Works no.	SAR no.	Class
NBL	1919	21738	1520	12AR
NBL	1919	21739	1521	12A
NBL	1919	21740	1522	12AR
NBL	1919	21741	1523	12AR
NBL	1919	21742	1524	12A
NBL	1919	21743	1525	12A
NBL	1919	21744	1526	12A
NBL	1919	21745	1527	12A
NBL	1919	21746	1528	12A
NBL	1919	21747	1529	12AR
NBL	1919	21748	1530	12AR
NBL	1919	21749	1531	12A
NBL	1919	21750	1532	12AR
NBL	1919	21751	1533	12A
NBL	1919	21752	1534	12AR
NBL	1919	21753	1535	12AR
NBL	1919	21754	1536	12AR
NBL	1919	21755	1537	12AR
NBL	1919	21756	1538	12A
NBL	1919	21757	1539	12A
Henschel	1928	21046	1540	12AR
Henschel	1928	21047	1541	12AR
Henschel	1928	21048	1542	12AR
Henschel	1928	21049	1543	12AR
Henschel	1928	21050	1544	12AR
Henschel	1928	21051	1545	12AR
Henschel	1929	21428	1546	12AR
Henschel	1929	21429	1547	12A
Henschel	1929	21430	1548	12A
Henschel	1929	21431	1549	12AR
Henschel	1929	21432	1550	12AR
Henschel	1929	21433	2103	12AR
Henschel	1929	21434	2104	12AR
Henschel	1929	21435	2105	12AR
Henschel	1929	21436	2106	12A
Henschel	1929	21437	2107	12A
Henschel	1929	21438	2108	12AR
Henschel	1929	21439	2109	12AR
Henschel	1929	21440	2110	12AR
NBL	1921	22751	2111	12A
NBL	1921	22752	2112	12AR
NBL	1921	22753	2113	12AR
NBL	1921	22754	2114	12A
NBL	1921	22755	2115	12AR
NBL	1921	22756	2116	12AR
NBL	1921	22757	2117	12A
NBL	1921	22758	2118	12AR
NBL	1921	22759	2119	12AR
NBL	1921	22760	2120	12AR
NBL	1921	22761	2121	12AR
NBL	1921	22762	2122	12AR
NBL	1921	22763	2123	12A
NBL	1921	22764	2124	12AR
NBL	1921	22765	2125	12AR
NBL	1929	23891	2126	12A
NBL	1929	23892	2127	12AR
NBL	1929	23893	2128	12AR
NBL	1929	23894	2129	12AR
NBL	1929	23895	2130	12A
NBL	1929	23896	2131	12AR
NBL	1929	23897	2132	12AR
NBL	1929	23898	2133	12A
NBL	1929	23899	2134	12A
NBL	1929	23900	2135	12AR
NBL	1929	23901	2136	12AR
NBL	1929	23902	2137	12AR
NBL	1929	23903	2138	12A

Service

When new, the Class 12A locomotives were placed in service hauling coal on the section from Witbank

Witbank

Witbank , also known as eMalahleni is a city situated on the Highveld of Mpumalanga, South Africa, within the eMalahleni Local Municipality. The name Witbank is Afrikaans for White Ridge and is named after a white sandstone outcrop where wagon transport drivers rested...

to Germiston. The unreboilered locomotives spent a large part of their working lives in the Transvaal, mainly in the Western Transvaal and shedded at Springs and Germiston, a few in the Eastern Transvaal shedded at Nelspruit

Nelspruit

Nelspruit is a city of more than 500,000 people situated in northeastern South Africa. It is the capital of the Mpumalanga province . Located on the Crocodile River, Nelspruit lies about west of the Mozambique border and east of Johannesburg. The towns of Nelspruit are Kanyamazane and Pienaar...

and Waterval Boven

Waterval Boven

Waterval Boven is a small town situated on the edge of the Escarpment on the banks of the Elands River above the 75m Elands Falls on the railway line from Pretoria to Maputo in Mpumalanga, South Africa. Hence the name which means "above the waterfall" in Dutch...

, and one at De Aar in the Cape Province. In 1977 all the Class 12A locomotives were relocated to the Cape Northern system for shunting at De Aar and at Beaconsfield in Kimberley.

The more numerous reboilered Class 12AR locomotives worked throughout most parts of South Africa, being shedded at Kimberley, De Aar, Port Elizabeth and East London in the Cape Province, Glencoe and Newcastle in Natal, Klerksdorp in Transvaal and Kroonstad in the Orange Free State.

Industrial service

None of the SAR Class 12A or Class 12AR locomotives were sold into industrial service, but between 1947 and 1953 eight Class 12A locomotives, similar to the unreboilered SAR locomotives but without superheaters, were built new for industrial service by NBL.

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