South African Class 12B 4-8-2
South African Class 12B & 12R 4-8-2 | |
---|---|
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 |
• Grate 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: | |
• Firebox | ♠ 160 sq ft (15 m2) ♥ 142 sq ft (13.2 m2) |
• Tubes | ♠ 2,328 sq ft (216.3 m2) ♥ 1,933 sq ft (179.6 m2) |
• Total surface | ♠ 2,488 sq ft (231.1 m2) ♥ 2,075 sq ft (192.8 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 | Johnston link-and-pin AAR knuckle (1930s) |
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 | c. 1984 |
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
Classification
![](http://upload.wikimedia.org/wikipedia/commons/thumb/4/49/D.A._Hendrie.jpg/150px-D.A._Hendrie.jpg)
The separate 12B 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][5][6]
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 unknown 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][5][6][7]
Their original Belpaire saturated steam boilers were fitted with Ramsbottom safety valves, while the Watson Standard superheated steam boiler was fitted with Pop safety valves.[5][6]
Service
South African Railways
All thirty locomotives were placed in service on the Cape Midland to work on the mainline out of
The Class 12Rs saw mainline work until well into 1969, when the arrival of new Class 33-400 diesel-electrics brought almost fifty years of mainline service to an end. The entire Class gave more than fifty years of service before the first one was withdrawn.[4]
Even in their twilight years, these locomotives still saw mainline service on the Klipplaat run and as local goods haulers around Port Elizabeth.[8]
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.[7]
Works numbers
The Baldwin works numbers did not run consecutively for the whole order and are shown in the table.[2][3]
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 |
Preservation
Class | Number | Works nmr | THF / Private | Leaselend / Owner | Current Location | Outside South Africa | ? |
---|---|---|---|---|---|---|---|
12R | 1865 | BP 5994 | Private | Kimberley Locomotive Depot | |||
12R | 1947 | BALDWIN 52754 | THF | Reefsteamers | Germiston Locomotive Depot | ||
12R | 1505 | NBL 20176 | THF | Umgeni Steam Railway | Kloofstation (Inchaga) | ||
12R | 1510 | NBL 20812 | Private | Creighton Station | |||
12A | 2111 | NBL 22751 | THF | Bloemfontein Locomotive Depot | |||
12AR | 1535 | NBL 21753 | THF | Reefsteamers | Germiston Locomotive Depot |
Illustration
-
Class 12R no. 1939 on the shunt at New Brighton, 31 March 1979
References
![](http://upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/30px-Commons-logo.svg.png)
- ^ a b c d 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.
- ^ ISBN 0869772112.
- ^ ISBN 978-0-7153-5427-8.
- ^ a b c Soul of A Railway, System 3, Part 10: The Midland Main Line, Part 2, Paterson to Alicedale. Captions 4, 31 (Accessed on 15 February 2017)
- ^ a b c 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.
- ^ a b c 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.
- ^ ISBN 0715386387.
- ^ a b Soul of A Railway, System 3, Part 9: The Midland Main Line, Part 1, Port Elizabeth to Paterson. Captions 14, 52, 58 (Accessed on 5 February 2017)