South African Class 12B 4-8-2

South African Class 12B & 12R 4-8-2

Class 12R no. 1931 at Port Elizabeth sheds, with Belpaire firebox, c. 1945

Type and origin
♠ Class 12B as built with a Belpaire firebox ♥ Class 12R rebuilt with a Watson Standard boiler
Power type	Steam
Designer	South African Railways (D.A. Hendrie)
Builder	Baldwin Locomotive Works
Serial number	52476, 52558-52559, 52583-52584, 52649-52651, 52690-52693, 52712-52713, 52723-52724, 52754-52767
Model	Class 12B
Build date	1920
Total produced	30

Specifications
Configuration	4-8-2 (Mountain)
Driver	2nd coupled axle
Gauge	3 ft 6 in (1,067 mm) Cape gauge
Leading dia.	28 ¹⁄₂ in (724 mm)
Coupled dia.	51 in (1,295 mm)
Trailing dia.	33 in (838 mm)
Tender wheels	34 in (864 mm)
Wheelbase	58 ft 3 ³⁄₄ in (17,774 mm)
• Engine	31 ft 9 ¹⁄₂ in (9,690 mm)
• Leading	6 ft 2 in (1,880 mm)
• Coupled	13 ft 6 in (4,115 mm)
• Tender	16 ft 9 in (5,105 mm)
• Tender bogie	4 ft 7 in (1,397 mm)
Length:
• Over couplers	66 ft 8 in (20,320 mm)
Height	♠ 12 ft 10 in (3,912 mm) ♥ 12 ft 7 ¹⁄₂ in (3,848 mm)
Frame type	Plate
Axle load	♠ 16 LT 15 cwt (17,020 kg) ♥ 17 LT 9 cwt (17,730 kg)
• Leading	♠ 15 LT 13 cwt (15,900 kg) ♥ 16 LT 2 cwt (16,360 kg)
• 1st coupled	♠ 16 LT 13 cwt (16,920 kg) ♥ 16 LT 15 cwt (17,020 kg)
• 2nd coupled	♠ 16 LT 15 cwt (17,020 kg) ♥ 17 LT 9 cwt (17,730 kg)
• 3rd coupled	♠ 16 LT 14 cwt (16,970 kg) ♥ 16 LT 17 cwt (17,120 kg)
• 4th coupled	♠ 16 LT 15 cwt (17,020 kg) ♥ 16 LT 15 cwt (17,020 kg)
• Trailing	♠ 12 LT 4 cwt (12,400 kg) ♥ 11 LT 16 cwt (11,990 kg)
• Tender bogie	Bogie 1: 27 LT 10 cwt (27,940 kg) Bogie 2: 23 LT 11 cwt (23,930 kg)
• Tender axle	13 LT 15 cwt (13,970 kg)
Adhesive weight	♠ 66 LT 17 cwt (67,920 kg) ♥ 67 LT 16 cwt (68,890 kg)
Loco weight	♠ 94 LT 14 cwt (96,220 kg) ♥ 95 LT 14 cwt (97,240 kg)
Tender weight	51 LT 1 cwt (51,870 kg)
Total weight	♠ 145 LT 15 cwt (148,100 kg) ♥ 146 LT 15 cwt (149,100 kg)
Tender type	MP1 (2-axle bogies) MP, MP1, MR, MS, MT, MT1, MT2, MX, MY, MY1 permitted
Fuel type	Coal
Fuel capacity	10 LT (10,160 kg)
Water cap	4,250 imp gal (19,300 l)
Firebox type	♠ Belpaire - ♥ Round-top
• Firegrate area	♠ 40 sq ft (3.7 m²) ♥ 37 sq ft (3.4 m²)
Boiler:
• Model	Watson Standard no. 2
• Pitch	♠ 7 ft 7 in (2,311 mm) ♥ 7 ft 8 ¹⁄₄ in (2,343 mm)
• Diameter	♠♥ 5 ft 7 ¹⁄₂ in (1,714 mm)
• Tube plates	♠ 20 ft (6,096 mm) ♥ 19 ft 4 in (5,893 mm) steel ♥ 19 ft 3 ⁵⁄₈ in (5,883 mm)
• Small tubes	♠ 139: 2 ¹⁄₄ in (57 mm) ♥ 87: 2 ¹⁄₂ in (64 mm)
• Large tubes	♠ 24: 5 ¹⁄₂ in (140 mm) ♥ 30: 5 ¹⁄₂ in (140 mm)
Boiler pressure	♠♥ 190 psi (1,310 kPa)
Safety valve	♠ Ramsbottom - ♥ Pop
Heating surface	♠ 2,488 sq ft (231.1 m²) ♥ 2,075 sq ft (192.8 m²)
• Tubes	♠ 2,328 sq ft (216.3 m²) ♥ 1,933 sq ft (179.6 m²)
• Firebox	♠ 160 sq ft (15 m²) ♥ 142 sq ft (13.2 m²)
Superheater:
• Heating area	♠ 574 sq ft (53.3 m²) ♥ 492 sq ft (45.7 m²)
Cylinders	Two
Cylinder size	22 ¹⁄₂ in (572 mm) bore 26 in (660 mm) stroke
Valve gear	Walschaerts
Valve type	Piston
Couplers	Bell link-and-pin AAR knuckle (1950s)

Performance figures
Tractive effort	♠♥ 36,780 lbf (163.6 kN) @ 75%

Career
Operators	South African Railways
Class	Class 12B & 12R
Number in class	30
Numbers	1931-1960
Delivered	1920
First run	1920
Withdrawn	1980s

The leading coupled axle had flangeless wheels

The South African Railways Class 12B 4-8-2 of 1920 was a steam locomotive.

In 1920, the South African Railways placed thirty Class 12B steam locomotives with a 4-8-2 Mountain type wheel arrangement in service.^[1]^[2]

Manufacturer

In May 1920, an additional thirty locomotives, built to the Class 12 design of SAR Chief Mechanical Engineer (CME) D.A. Hendrie, were delivered to the South African Railways (SAR) from Baldwin Locomotive Works in the United States of America. Most of them were erected in the SAR workshops, but a few were contracted to James Brown and Company at Durban for erection. Even though they were very similar to the second and subsequent orders of the Class 12, they were classified separately as Class 12B and numbered in the range from 1931 to 1960. They were also built with plate frames, Walschaerts valve gear and Belpaire fireboxes.^[1]^[2]^[3]

Classification

D.A. Hendrie

The separate classification has been ascribed to the fact that the wheelbase of the leading bogie was 2 inches (51 millimetres) longer than on the original Class 12 locomotives. This was probably not the reason, bearing in mind that only the first eight out of altogether 46 Class 12 locomotives were built with leading bogies with a 6 feet (1,829 millimetres) wheelbase, while the other thirty-eight all had leading bogies with a 6 feet 2 inches (1,880 millimetres) wheelbase, the same as the Class 12B. More likely, the separate classification was simply based on the fact that the Class 12 was British-built while the Class 12B was American-built.^[1]^[2]^[3]

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. Such Watson Standard reboilered locomotives were reclassified by adding an "R" suffix to their classification.^[2]^[4]^[5]

All thirty Class 12B locomotives were eventually reboilered with Watson Standard no. 2 boilers. In the process, they were also equipped with Watson cabs, with their distinctive slanted fronts, compared to the conventional vertical fronts of their original cabs. Upon reboilering, the original reason for the separate classification was ignored and, instead of becoming Class 12BR, the reboilered locomotives were reclassified to Class 12R along with the reboilered Class 12 locomotives.^[1]^[4]^[5]^[6]

Their original Belpaire boilers were fitted with Ramsbottom safety valves, while the Watson Standard boiler was fitted with Pop safety valves. Other obvious differences between an original and a Watson Standard reboilered locomotive are usually a rectangular regulator cover, just to the rear of the chimney on the reboilered locomotive and, in the case of the Classes 12B and 12R locomotives, the Watson cab and the absence of the Belpaire firebox hump between the cab and boiler on the reboilered locomotives.^[4]^[5]

Service

South African Railways

They were placed in service on the Cape Midland, working on the mainline out of Port Elizabeth, where they largely remained until being withdrawn from service. Even though they were not designed to be mixed traffic locomotives, they saw service on both passenger and goods working.^[2]^[3]

Industrial

For some reason, few Class 12Rs ended up in industrial service, despite their evident suitability for such work. Of the ex Class 12B locomotives, only no. 1936 was sold to Enyati Colliery and later became Western Holdings Gold Mine's no. 8.^[6]

Works numbers

The Baldwin works numbers did not run consecutively for the whole order and are shown in the table.^[2]^[3]

Class 12B 4-8-2
Works numbers
SAR no.	Works no.
1931	52476
1932	52558
1933	52559
1934	52583
1935	52584
1936	52649
1937	52650
1938	52651
1939	52690
1940	52691
1941	52692
1942	52693
1943	52712
1944	52713
1945	52723
1946	52724
1947	52754
1948	52755
1949	52756
1950	52757
1951	52758
1952	52759
1953	52760
1954	52761
1955	52762
1956	52763
1957	52764
1958	52765
1959	52766
1960	52767

Illustration

The main picture shows Class 12B no. 1931 at the Port Elizabeth sheds on 31 March 1979.

12R no. 1939 at New Brighton, 31 March 1979

References

1 2 3 4 Espitalier, T.J.; Day, W.A.J. (1945). The Locomotive in South Africa - A Brief History of Railway Development. Chapter VII - South African Railways (Continued). South African Railways and Harbours Magazine, October 1945. p. 780.
1 2 3 4 5 6 Paxton, Leith; Bourne, David (1985). Locomotives of the South African Railways (1st ed.). Cape Town: Struik. pp. 10–11, 54–56. ISBN 0869772112.
1 2 3 4 Holland, D.F. (1972). Steam Locomotives of the South African Railways, Volume 2: 1910-1955 (1st ed.). Newton Abbott, Devon: David & Charles. pp. 38–41, 82. ISBN 978-0-7153-5427-8.
1 2 3 South African Railways & Harbours/Suid Afrikaanse Spoorweë en Hawens (15 Aug 1941). Locomotive Diagram Book/Lokomotiefdiagramboek, 3'6" Gauge/Spoorwydte. SAR/SAS Mechanical Department/Werktuigkundige Dept. Drawing Office/Tekenkantoor, Pretoria. p. 43.
1 2 3 South African Railways & Harbours/Suid Afrikaanse Spoorweë en Hawens (15 Aug 1941). Locomotive Diagram Book/Lokomotiefdiagramboek, 2'0" & 3'6" Gauge/Spoorwydte, Steam Locomotives/Stoomlokomotiewe. SAR/SAS Mechanical Department/Werktuigkundige Dept. Drawing Office/Tekenkantoor, Pretoria. pp. 6a-7a, 41, 43.
1 2 Durrant, A E (1989). Twilight of South African Steam (1st ed.). Newton Abbott, London: David & Charles. p. 59. ISBN 0715386387.

Wikimedia Commons has media related to South African Class 12B (4-8-2).

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

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

South African steam locomotive tenders

Cape gauge	Type CL Type CZ Type ET Type ET1 Type EW Type EW1 Type EW2 Type FT Type GT Type HT Type JT Type JT1 Type JV Type KT Type LP Type MP Type MP1 Type MR Type MS Type MT Type MT1 Type MT2 Type MX Type MY Type MY1 Type SH Type SK Type TJ Type TL Type TM Type WE Type WG Type X-17 Type X-20 Type XC Type XC1 Type XD Type XE Type XE1 Type XF Type XF1 Type XF2 Type XJ Type XM Type XM1 Type XM2 Type XM3 Type XM4 Type XP1 Type XS Type YB Type YC Type YE Type YE1 Type ZA Type ZB Type ZC Type ZE

List of South African locomotive classes South African locomotive history

This article is issued from Wikipedia - version of the 4/26/2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.