South African Class 19D 4-8-2

South African Railways Class 19D

Company type	Steam locomotive class
Industry	Railway transport
Predecessor	Class 19C
Founded	1937
Headquarters	South Africa
Products	Steam locomotives

Overview of the South African Class 19D 4-8-2 Steam Locomotive

The South African Railways Class 19D 4-8-2 steam locomotive was introduced in 1937.

From 1937 until 1949, the South African Railways commissioned a total of 235 Class 19D locomotives featuring a 4-8-2 Mountain wheel configuration. Subsequently, between 1951 and 1955, an additional 33 units were constructed for various other users, including Rhodesian and Angolan rail networks as well as the Nkana and Wankie mining operations. This production volume established the Class 19D as the most widely manufactured steam locomotive type in South Africa's history.

Manufacturers

File:Class 19D no. 2636.jpg

Škoda-built locomotive no. 2636 featuring a domeless boiler and Type MR tender, operating on a passenger service near Vryburg, Northern Cape, October 1971

File:Class19D-2650-01.jpg

FOTR's Krupp-manufactured no. 2650 with domeless boiler and Type MX Torpedo tender, photographed at Cullinan, Gauteng, 26 September 2010

File:Saiccor No. 1 - Ex SAR Class 19D No. 2697.jpg

Saiccor’s Borsig-built no. 2697 equipped with a domeless boiler and Type MP1 tender, located at Exchange Yard, Umkomaas, 2 July 2012

File:SAR Class 19D 2749 (4-8-2).JPG

RSH-produced no. 2749 with Type MX Torpedo tender, captured at Voorbaai, Mosselbaai, Western Cape, 19 October 2009

The Class 19D 4-8-2 steam locomotive represents the ultimate evolution within the Class 19 series. The initial fundamental design of the Class 19 was developed in the late 1920s by Test Engineer M.M. Loubser, who later served as Chief Mechanical Engineer (CME) of the South African Railways (SAR) from 1939 to 1949. This design effort was initiated following a request from Colonel F.R. Collins, SAR CME between 1922 and 1929.

The definitive iteration of the Class was completed in 1937 under the direction of W.A.J. Day, who held the CME position from 1936 to 1939. The Class 19D was essentially an enhanced version of the Class 19C, distinguished by its use of piston valves combined with Walschaerts valve gear instead of the earlier rotary cam poppet valve gear.

From 1937 through to 1955, a total of 268 Class 19D units were constructed in seven production runs by six different manufacturers located across Czechoslovakia, Germany, and the United Kingdom. These locomotives were supplied to the SAR as well as other rail operators in Southern Africa.

• In the initial batch of forty locomotives built in Germany during 1937, twenty units featuring domeless boilers were produced by Friedrich Krupp in Essen, numbered between 2506 and 2525. Another twenty were manufactured by Borsig Lokomotiv Werke in Hennigsdorf, Berlin, assigned numbers from 2526 to 2545.
• The following year, in 1938, an order for ninety-five additional locomotives was fulfilled by three producers: Škoda Works in Czechoslovakia delivered fifteen units numbered from 2626 to 2640; Krupp supplied forty locomotives fitted with domed boilers numbered between 2641 and 2680; and Borsig produced another forty numbered from 2681 to 2720.
• Production was interrupted by the outbreak of World War II, and post-war acquisitions shifted towards British manufacturers. In 1947, Robert Stephenson & Hawthorns (RSH) of Darlington, England, supplied fifty post-war Class 19D locomotives numbered from 2721 to 2770. Notably, engine no. 2734 (RSH works no. 7247) was lost at sea off England’s east coast during transit. Its replacement (works no. 7360) was insured and assigned the same number, preserving continuity.
• The last batch for SAR consisted of fifty units delivered in 1949 by the North British Locomotive Company (NBL) based in Glasgow, Scotland, numbered from 3321 to 3370. These were equipped with Type MX Torpedo tenders.
• In addition, six locomotives were built by NBL in 1951 specifically for the Caminho de Ferro de Benguela (CFB) operating in Angola.
• Between the years of 1951 and 1953, Henschel & Son constructed twenty-one units destined for the Rhodesia Railways (RR) and Nkana copper mine located in Northern Rhodesia.
• Finally, four more locomotives were manufactured by NBL in 1955 for deployment at the Wankie coal mine situated in Southern Rhodesia.

Characteristics

The Class 19D, often referred to as Dolly, closely resembled its forerunner, the Class 19C, but featured piston valves and Walschaerts valve gear as specified by Day, replacing the earlier rotary cam poppet valve gear. The cylinders were reengineered to incorporate straighter steam ports, while the valve gear was enhanced with an extended steam lap and increased valve travel. Aside from these modifications, the design remained consistent with the Class 19C. Notably, the final five locomotives in the initial Krupp batch, numbered 2521 through 2525, were equipped with exhaust steam injectors.

The cylinders were constructed as combined units, cast in two identical, interchangeable halves—each comprising one cylinder and a section of the smokebox saddle. Made from cast iron and fitted with liners, their steam passage design allowed for a substantial cross-sectional area accommodating both live and exhaust steam.

All driving wheels featured flanges. Roller bearings supported the axle boxes of the leading and trailing wheels, whereas the solid bronze axle boxes on the coupled wheels were lubricated with soft grease. Soft grease lubrication extended throughout the motion gear except for piston rods, valve spindles, and main crossheads, which received oil lubrication. Two four-feed sight lubricators located within the cab delivered oil to both steam chests and cylinders.

Watson Standard boilers

The Class 19D locomotives were initially supplied with a Watson Standard no. 1A boiler featuring Ross Pop safety valves set to a pressure of 200 pounds per square inch (1,379 kilopascals). The regulator employed a multiple-valve arrangement positioned on the saturated steam side of the superheater header in line with SAR standards. This boiler type was part of a series of standardised designs introduced by A.G. Watson, Day's predecessor as CME, reflecting his policy of standardisation. Additionally, these locomotives sported Watson cabs distinguished by their slanted fronts.

Despite adhering to specifications overall, the first batch of Class 19D engines built by Krupp and Borsig in 1937 and 1938 exhibited two distinct boiler configurations. The Krupp units were delivered with domeless boilers, whereas those from Borsig complied fully with specifications by incorporating domed boilers.

Although these domeless boilers deviated from the prescribed Watson Standard no. 1A design due to lacking a dome, they were accepted because all other dimensions matched those of the standard boiler. It seems Krupp independently concluded that a dome was unnecessary since no regulator was housed there—only a standpipe was present. Instead of a dome, Krupp installed a manhole cover supporting two Pop safety valves, while steam collection occurred via an array of collecting pipes positioned high within the boiler similarly to those used in the Class 16E.

Later deliveries of Class 19D locomotives featured domed Watson Standard no. 1A boilers equipped with the conventional standpipe steam collector located at dome apex height, channeling steam to the multi-valve regulator housed in the smokebox. From a technical perspective, domes were preferred whenever loading gauge restrictions allowed their installation since they avoided complications caused by crowding multiple pipes inside the boiler inherent in domeless designs. Operationally, drivers reported no noticeable difference in performance between locomotives fitted with domed versus domeless boilers.

Watson Standard boilers were designed for interchangeability among locomotives. During extensive overhauls over time, many of these twenty Krupp-produced domeless boilers were transferred between engines. Consequently, some locomotives built by other manufacturers as well as certain Class 19A and 19C units eventually operated with some of these domeless boilers installed.

Tenders

Due to the extended production period and involvement of multiple manufacturers, the six principal variants of the Class 19D exhibited differing overall weights and axle load distributions, as detailed in the accompanying table and infobox specifications. Throughout the eleven years of Class 19D production for the SAR, several modifications were introduced.

• Initially, the Class 19D locomotives were supplied with Type MT tenders, which featured a coal capacity of 12 long tons (12.2 tonnes) and water capacity of 6,000 imperial gallons (27,300 litres). However, the axle load of 16 long tons 11 hundredweight (16,820 kilograms) on these tenders exceeded the limits permitted on the branch lines for which these engines were intended. Consequently, upon delivery, these Type MT tenders were replaced with smaller modified Type MP1 tenders sourced from some reboilered mainline locomotives. The Type MP1 tenders, many later rebuilt into Type MR tenders, had a lighter axle load of 13 long tons 15 hundredweight (13,970 kilograms), making them more appropriate for branch line operation. This approach was consistently applied to all Class 19B, 19C, and early Class 19D locomotives, except for the final series of Class 19D units numbered 3321 to 3370.
• In 1944, Dr. M.M. Loubser, then Chief Mechanical Engineer and involved with the Class 19 series design since its inception in the late 1920s, implemented further enhancements to the Class 19D. All locomotives produced after World War II were equipped with vacuum brake systems alongside their existing steam brakes. The two 21 inches (533 millimetres) vacuum cylinders were installed beneath the running boards on each side approximately midway between the leading coupled wheels and the driving wheels, while the vacuum chamber was aligned with the intermediate coupled wheels.
• The last batch constructed by NBL, bearing numbers 3321 to 3370, featured Type MX tenders characterized by cylindrical water tanks reminiscent of American Vanderbilt-style tenders. Designed by Dr. M.M. Loubser, these tank wagon-type tenders ran on three-axle Buckeye bogies and became popularly known as Torpedo tenders.

South African Railways

Throughout their operational tenure, numerous tender swaps took place among Class 19D locomotives to better suit their assigned regions and service requirements. On mainline routes, Type MX Torpedo tenders were generally favored due to their increased coal and water capacities. By the time Class 19Ds were retired in the late 1980s, many units had exchanged their original Type MP1 or Type MR tenders for Type MX Torpedo tenders or vice versa. Furthermore, Type MX Torpedo tenders were also paired with Class 19B and Class 19C locomotives.

The Class 19D was South Africa’s most numerous branch line steam locomotive class, with a total production of 235 units for SAR—only twenty fewer than the widely produced Class 15F mainline engines, which hold the record for greatest quantity among South African steam classes. Known for its adaptability, the Class 19D operated extensively across main and branch lines nationwide except in the Western Cape, where Class 19C locomotives predominated.

Their duties ranged from hauling local and international passenger services on the route between Warrenton and Mafeking, a corridor connecting South Africa with Northern Rhodesia via Bechuanaland and Southern Rhodesia, to assignments on secondary and branch lines and later as yard shunters. Occasionally, Class 19Ds ran through from Mafikeng in South Africa through Botswana all the way to Bulawayo in Zimbabwe. Additionally, SAR hired out these locomotives for shunting operations on Rhodesia Railways at Beit Bridge and in Mozambique at Lourenco Marques.

From approximately 1972 onwards, with the introduction of Union Carriage & Wagon-built Blue Train stock stabled at Pretoria, after Capital Park's blue-liveried Class S2 no. 3793 was withdrawn along with its class between 1979 and 1980, shunting duties at Pretoria station’s carriage yard were assumed by a blue-painted Class 19D no. 2749—the sole unit in this class to wear a livery other than standard black. Besides yard work, this distinctive blue locomotive known as Dolly was frequently requested to haul the Cullinan train during the annual Jacaranda bloom season.

The Class 19D continued operating until steam traction was phased out on South African Railways, being among the last steam locomotives replaced by electric and diesel-electric alternatives.

Additional Operators

Several other railways in Southern Africa, along with certain industrial users, also acquired locomotives modeled on the Class 19D blueprint. When accounting for these international units, the total production of Class 19D locomotives reached 268, surpassing even the numbers built for the Class 15F.

Benguela Railway

In 1951, NBL manufactured six locomotives for Angola’s Caminho de Ferro de Benguela (CFB or Benguela Railway), designated as their 11th Class and numbered between 401 and 406. These engines operated on either wood or coal fuel depending on their location. To accommodate wood fuel, their tenders were fitted with slatted frames atop the bunker to expand fuel capacity. For instance, in August 1972, locomotives 401, 402, and 406 were stationed at Lobito and ran on coal, while numbers 403 and 405 at Luso and number 404 at Nova Lisboa were observed burning wood.

Rhodesia Railways

Between 1951 and 1953, Henschel & Son produced twenty locomotives for Rhodesia Railways as their 19th class, numbered from 316 to 335. These units featured tenders resembling the SAR Torpedo type but utilized plate frame bogies instead of the cast frame Buckeye bogies typically seen.

A unique RR 19C class locomotive, number 336, was built by Henschel in 1953 as a condensing engine. Following a collision in 1956, it was reconstructed into a non-condensing version of the 19th Class and returned to service in 1958. Its condensing tender was converted locally in Bulawayo into a Torpedo tender by installing a tank and coal bunker on the existing frame. This modified tender is currently paired with locomotive no. 330, which is preserved at the Bulawayo Railway Museum.

By June 1975, only three locomotives remained operational within Rhodesia Railways, all assigned to the Bulawayo depot, with two temporarily stationed at Mafeking (Mahikeng) in South Africa.

Nkana Mines

Henschel built two locomotives in 1952 for the Nkana copper mines located in Northern Rhodesia, numbered 107 and 108. These were sold in 1967 to a scrap dealer in Rhodesia who subsequently transferred them to Rhodesia Railways. After undergoing refurbishment, they re-entered service in 1968 as RR 19B Class numbers 337 and 338.

Wankie Colliery

In 1955, NBL constructed four additional locomotives based on the Class 19D design but without superheating features. These were numbered from 1 to 4 and delivered to Wankie Colliery in Southern Rhodesia.

Industrial applications

Upon their withdrawal from mainline service, a number of Class 19D locomotives found new roles within various industrial operations. By the late 1980s, several units were actively employed at facilities such as Dunn's, Saiccor, Loraine Gold Mine, and Bamangwato Concessions Ltd. (BCL) in Botswana, with additional locomotives joining these industrial fleets subsequently.

Even as recently as 2011, two Class 19D engines that had previously served at Vaal Reefs Gold Mine during the 1980s were acquired by BCL at Selebi-Phikwe. These locomotives, likely numbers 2678 and 2689, had been left exposed at Jan Kempdorp for approximately two decades following their retirement. The plan was to refurbish them for continued use at the mine, which still operated ex-SAR Class 19D and ex-RR 19th class engines. By June 2012, one of these locomotives had returned to active duty. However, the mine ceased operations in late 2016, rendering the entire collection inactive and available for sale as of December 2018.

Red Devil prototype

Before SAR mechanical engineer David Wardale received authorization in 1979 to reconstruct a Class 25NC 4-8-4 locomotive into the famed Class 26 Red Devil, he was permitted to conduct experimental modifications on a Class 19D unit. The locomotive chosen for this trial was Krupp-built no. 2644, which was known for its relatively poor steaming performance within the class.

This trial involved fitting a gas producer combustion system (GPCS) alongside a dual Lempor exhaust setup and other minor enhancements. The Lempor exhaust featured a four-jet blastpipe complemented by extended petticoats designed to optimize ejector efficiency. To accommodate these changes, the smokebox was lengthened by 300 millimetres (11.8 inches). Additionally, steam distribution within the cylinders was enhanced by refining the piston valve edges and installing an extra valve ring on each to minimize leakage. The firebox was adapted to incorporate the GPCS system, whereby primary combustion air was limited through dampers and a redesigned grate, while secondary air was introduced above the firebed via ducts in the firebox sides.

To generate turbulence within the firebox and reduce clinkering, steam jets were employed with exhaust steam directed beneath the grate. Improvements were also made to sanding equipment, including the installation of de-sanding jets that cleaned rails after passage of the locomotive.

These modifications significantly boosted the locomotive’s steaming capacity and enabled it to deliver substantially greater power output while reducing fuel consumption by approximately 20% to 25% compared to standard Class 19D engines. The positive outcome of this experiment persuaded SAR management of the project's feasibility, ultimately leading to the development of the Class 26 Red Devil.

Preservation

A significant number of Class 19D locomotives have been retained for historical and operational purposes.

Number (* MX tender)	Works number	THF / Private	Lessee / Owner	Present Location	Outside South Africa	Remarks
2510	Krupp 1622	Private	Municipality	Barkly East (Town Centre)
2526	Borsig 14643	Private	New Cape Central Railway	Waterval-Boven Locomotive Depot
2534	Borsig 14651	Private	Municipality	Naboomspruit (Town Centre)
2540 *	Borsig 14657	THF		Germiston Locomotive Depot
2541	Borsig 14658	Private	Municipality	Potgietersrus (Town Centre)		Domeless boiler
2633	Skoda 928	Private	Sandstone Heritage Trust	Sandstone Heritage Trust
2637	Skoda 932	THF	Umgeni Steam Railway	Masons Mill Locomotive Depot
2640 *	Skoda 935	THF		Voorbaai Locomotive Depot
2649 *	Krupp 1829	THF		George Locomotive Depot		Last steam engine employed on the Outeniqua Choo Tjoe
2650	Krupp 1830	THF	Wonder Steam Trains	Hermanstad (Station)		Domeless boiler
2654 *	Krupp 1834	Private	Sandstone Heritage Trust	Bloemfontein Locomotive Depot		In service
2656 *	Krupp 1836	Private	Municipality	Jan Kempdorp (Town Centre)		Domeless boiler
2666 *	Krupp 1849	THF		Queenstown Locomotive Depot		Domeless boiler
2669	Krupp 1852	THF	Paton's Country Narrow Gauge Railway	Creighton (Station)		Domeless boiler
2678 *	Krupp 1861	Private	Selebi-Phikwe copper mine	Selebi-Phikwe	Botswana	BCL LO813 (sold/scrapped)
2682	Borsig 14738	Private	Municipality	Schweizer-Reneke (Town Centre)
2683	Borsig 14734	THF	Voorbaai Locomotive Depot
2685	Borsig 14736	Private	Umgeni Steam Railway	Kloofstation (Inchanga)		Operational
2688	Borsig 14739	Private	Municipality	Warrenton (Town Centre)		Domeless boiler
2689 *	Borsig 14740	Private	Selebi-Phikwe copper mine	Selebi-Phikwe	Botswana	BCL LO812 (sold/scrapped)
2690 *	Borsig 14741	Private	Municipality	Wakkerstroom (Town Centre)
2695	Borsig 14746	Private	Ian Welch	Plimmerton	New Zealand
2696 *	Borsig14747	Private	Municipality	Volksrust (Town Centre)
2698 *	Borsig14749	THF	Voorbaai Locomotive Depot
2702 *	Borsig14753	Private	Rovos Rail	Capital Locomotive Depot	Named Bianca
2709	Borsig14760	THF	Krugersdorp Locomotive Depot			Domeless boiler
2711	Borsig14765	Private	North West Agricultural Museum	Lichtenburg
2714	Borsig14762	THF	Queenstown Locomotive Depot
2749 *	RSH7262	THF	Voorbaai Locomotive Depot
2765 *	RSH7278	Private	Selebi-Phikwe copper mine	Selebi-Phikwe	Botswana	BCL LO805 (sold/scrapped)
3321 *	NBL26041	Private	Ceres Railway Company	Ceres Golf Estate		Non-operational (oil burner)
3322	NBL26042	Private	Ceres Railway Company	Royal Cape Yacht Club		Operational (oil burner)
3323 *	NBL26043	THF	George Locomotive Depot
3324 *	NBL26044	THF	Voorbaai Locomotive Depot
3325	NBL26045	THF	Queenstown Locomotive Depot
3327	NBL26047	THF	Bloemfontein Locomotive Depot
3328 *	NBL26048	Private	Municipality	Coligny (Town Centre)
3330	NBL26050	THF	Queenstown Locomotive Depot
3332 *	NBL26052	Private	Ian Welch		Robertson, WC (NCCR)
3334 *	NBL26054	THF		Voorbaai Locomotive Depot		(oil burner)
3337	NBL26057	THF		Queenstown Locomotive Depot
3341 *		NBL26061		Private		Grand Bradley		Germiston Locomotive Depot		BCL LO807

Works numbers and renumbering

The following table details the manufacturers of the Class 19D locomotives, their respective works numbers, construction years, railway operators, and engine numbers. The "Notes" section includes batch code symbols corresponding to the weight classifications as outlined in the infobox.

Borsig 14645 1937 SAR 2528 ♠ Borsig 14646 1937 SAR 2529 ♠ Borsig 14647 1937 SAR 2530 ♠ Borsig 14648 1937 SAR 2531 ♠ Borsig 14649 1937 SAR 2532 ♠ Borsig 14650 1937 SAR 2533 ♠ Borsig 14651 1937 SAR 2534 ♠ Borsig 14652 1937 SAR 2535 ♠ Borsig 14653 1937 SAR 2536 ♠ Borsig 14654 1937 SAR 2537 ♠ Borsig 14655 1937 SAR 2538 ♠ Borsig 14656 1937 SAR 2539 ♠ Borsig 14657 1937 SAR 2540 ♠ Borsig 14658 1937 SAR 2541 ♠ Borsig 14659 1937 SAR 2542 ♠ Borsig 14660 1937 SAR 2543 ♠ Borsig 14661 1937 SAR 2544 ♠ Borsig 14662 1937 SAR 2545 ♠ Škoda 921 1938 SAR 2626 Template:Font color\ Škoda 922 1938 SAR 2627 Template:Font color\ Škoda 923 1938 SAR 2628 Template:Font color\ Škoda 924 1938 SAR 2629 Template:Font color\ Škoda 925 1938 SAR 2630 Template:Font color\ Škoda 926 1938 SAR 2631 Template:Font color\ Škoda 927 1938 SAR 2632 Template:Font color\ Škoda 928 1938 SAR 2633 Template:Font color\ Škoda 929 1938 SAR 2634 Template:Font color\ Škoda 930 1938 SAR 2635 Template:Font color\ Škoda 931 1938 SAR 2636 Template:Font color\ Škoda 932 1938 SAR 2637 Template:Font color\ Škoda 933 1938 SAR 2638 Template:Font color\ Škoda 934 1938 SAR 2639 Template:Font color\ Škoda 935 1938 SAR 2640 Template:Font color\ Krupp 1821 1938 SAR 2641 Template:Font color\ Krupp 1822 1938 SAR 2642 Template:Font color\ Krupp 1823 1938 SAR 2643 Template:Font color\ Krupp 1824 1938 SAR 2644 Template:Font color\ Krupp 1825 1938 SAR 2645 Template:Font color\ Krupp 1826 1938 SAR 2646 Template:Font color\ Krupp 1827 1938 SAR 2647 Template:Font color\ Krupp 1828 1938 SAR 2648 Template:Font color\ Krupp 1829 1938 SAR 2649 Template:Font color\ Krupp 1830 1938 SAR 2650 Template:Font color\ Krupp 1831 1938 SAR 2651 Template:Font color\ Krupp 1832 1938 SAR 2652 Template:Font color\ Krupp 1833 1938 SAR 2653 Template:Font color\ Krupp 1834 1938 SAR 2654 Template:Font color\ Krupp 1835 1938 SAR 2655 Template:Font color\ Krupp 1836 1938 SAR 2656 Template:Font color \ Krupp 1837 1938 SAR 2657 Template:Font color \ Krupp 1838 1938 SAR 2658 Template:Font color \ Krupp ... (table continues with similar pattern)

Class 19D 4-8-2 — manufacturers and works numbers

Manufacturer	Works Number	Year of Build	Railway Operator	Locomotive Number	Remarks
Krupp	1618	1937	SAR	2506	♠ Without dome
Krupp	1619	1937	SAR	2507	♠ Without dome
Krupp	1620	1937	SAR	2508	♠ Without dome
Krupp	1621	1937	SAR	2509	♠ Without dome
Krupp	1622	1937	SAR	2510	♠ Without dome
Krupp	1623	1937	SAR	2511	♠ Without dome
Krupp	1624	1937	SAR	2512	♠ Without dome
Krupp	1625	1937	SAR	2513	♠ Without dome
Krupp	1626	1937	SAR	2514	♠ Without dome
Krupp	1627	1937	SAR	2515	♠ Without dome
Krupp	1628	1937	SAR	2516	♠ Without dome
Krupp	1629	1937	SAR	2517	♠ Without dome
Krupp	1630	1937	SAR	2518	♠ Without dome
Krupp	1631	1937	SAR	2519	♠ Without dome
Krupp	1632	1937	SAR	2520	♠ Without dome
Krupp	1633	1937	SAR	2521	♠ Without dome
Krupp	1634	1937	SAR	2522	♠ Without dome
Krupp	1635	1937	SAR	2523	♠ Without dome
Krupp	1636	1937	SAR	2524	♠ Without dome
Krupp	1637	1937	SAR	2525	♠ Without dome
Borsig	14643	1937	SAR	2526	♠
Borsig	14644	1937	SAR 2527 ♠