South African Class 7D 4-8-0

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South African Class 7D 4-8-0
ex Rhodesia Railways 7th Class 4-8-0
SAR Class 7D 1353 (4-8-0) ex RR.JPG
Ex Rhodesia Railways 7th Class no. MR11, later no. MR18, then no. RRM67, finally SAR Class 7D no. 1353
Type and origin
Power type Steam
Designer Cape Government Railways
Builder Neilson, Reid and Company
Kitson and Company
North British Locomotive Company
Order number NR E834 & E835 (1899), E851 (1900)
NBL L313 & L322 (1903) [1]
Serial number NR 5675-5686, 5791-5802, 5817 [2]
Kitson 4062-4069 [3][4]
NBL 16085-16094, 16171-16180 [1][5][6]
Model CGR 7th Class
Build date 1899-1903
Total produced 52
Specifications
Configuration 4-8-0 "Mastodon"
Gauge 3 ft 6 in (1,067 mm) Cape gauge
Leading wheel
diameter
28.5 in (724 mm)
Driver diameter 42.75 in (1,090 mm)
Wheelbase Total: 46 ft 2 in (14.072 m)
Engine:
5 ft 3 in (1.600 m) bogie
12 ft (3.658 m) coupled
21 ft 3.5 in (6.490 m) total
Tender:
4 ft 7 in (1.397 m) bogie
16 ft 1 in (4.902 m) total
Length 53 ft 5.75 in (16.300 m)
Height 12 ft 10 in (3.912 m)
Frame Plate frame
Axle load 9 long tons (9.1 t) on 1st & 2nd drivers as built
9.7 long tons (9.9 t) on 2nd driver superheated
Weight on drivers 35.8 long tons (36.4 t) as built
38 long tons (38.6 t) superheated
Locomotive weight 46.5 long tons (47.2 t) NR & NBL
49.1 long tons (49.9 t) superheated
44.35 long tons (45.1 t) Kitson
Tender weight 34.1 long tons (34.6 t) NR & NBL
34.65 long tons (35.2 t) Kitson
Locomotive and tender
combined weight
92,764 lb (42.1 t) empty
74.55 long tons (75.7 t) w/o NR & NBL
83 long tons (84.3 t) w/o Kitson
Tender type ZE - ZA, ZB, ZC, ZE permitted
* 2 axle bogies
* 34 in (864 mm) wheels
* Length 23 ft 8.5 in (7.226 m)
Fuel type Coal
Fuel capacity 8 long tons (8.1 t) NR & NBL
6.5 long tons (6.6 t) Kitson
Water capacity 2,850 imp gal (13,000 l)
Boiler As built:
4 ft 4 in (1.321 m) inside diameter
10 ft 9 in (3.277 m) inside length
6 ft 8 in (2.032 m) pitch
Superheated:
4 ft 6 in (1.372 m) inside diameter
10 ft 9 in (3.277 m) inside length
6 ft 10 in (2.083 m) pitch
Boiler pressure 160 psi (1,100 kPa) as built
170 psi (1,170 kPa) adjusted
180 psi (1,240 kPa) superheated
Firegrate area 18 sq ft (1.672 m2)
Heating surface:
– Tubes
As built:
185 tubes 1.875 in (47.6 mm) diameter
976 sq ft (90.673 m2)
Superheated:
100 tubes 1.875 in (47.6 mm) diameter
18 tubes 5.5 in (140 mm) diameter
806 sq ft (74.880 m2)
– Firebox 102 sq ft (9.476 m2) NR & NBL
113 sq ft (10.498 m2) superheated
112 sq ft (10.405 m2) Kitson
– Total 1,078 sq ft (100.149 m2) NR & NBL
919 sq ft (85.378 m2) superheated
1,088 sq ft (101.079 m2) Kitson
Superheater type Not equipped as built
Superheater area 206 sq ft (19.138 m2)
Cylinders Two
Cylinder size 17 in (432 mm) bore
23 in (584 mm) stroke
Valve gear Stephenson
Performance figures
Tractive effort At 75% pressure, as built:
18,660 lbf (83.0 kN) at 160 psi (1,100 kPa)
19,810 lbf (88.1 kN) at 170 psi (1,170 kPa)
At 75% pressure, superheated:
22,240 lbf (98.9 kN) [7]
Factor of
adhesion
NR & NBL built: 4,32
Kitson built: 4.531 [1]
Career
Operator(s) Imperial Military Railways
Mashonaland Railways
Rhodesia Railways Northern Ext
Rhodesia Railways
South African Railways
Class IMR, MR, RRM & RR 7th Class
SAR Class 7D
Number in class RR 52, SAR 5
Number(s) BR 7-8, RR 1-50, IMR 110
SAR 1351-1355 [6]
Delivered 1899-1903 to RR, 1915 to SAR
First run 1899
Withdrawn 1972 [8]

The South African Class 7D 4-8-0 of 1915 is a South African steam locomotive from the South African Railways era.

Between 1899 and 1903 the Rhodesia Railways placed fifty-two Cape 7th Class 4-8-0 Mastodon steam locomotives in service. One more was obtained from the Imperial Military Railways in March 1901 as replacement for a locomotive that was damaged beyond local repair capabilities as a result of hostilities during delivery.[1]

In May 1915 five of these locomotives were sold to the South African Railways, where they were renumbered and reclassified, four of them to Class 7D and the remaining one erroneously to Class 7B. At the same time, the ex Imperial Military Railways locomotive was also sold back to South Africa and was, also erroneously, designated Class 7D.[1][6][8]

Rhodesian 7th Class[edit]

Fifty-two Cape 7th Class 4-8-0 steam locomotives were built for the Beira and Mashonaland and Rhodesia Railways (BMR), later the Rhodesia Railways (RR), between 1899 and 1903. These locomotives were acquired by Southern Rhodesia at the time when railways were still expanding from South Africa via the Bechuanaland Protectorate into Southern Rhodesia in the southwest and from Beira in Mozambique to Umtali in the east, and while the Anglo-Boer War was being waged. At the time the system was composed of several smaller railways, still largely under construction, that were eventually all linked up in 1902. These were:[1]

  • The fledgling Bechuanaland Railways (BR) that was still being operated by the Cape Government Railways (CGR) from Vryburg via Mafeking in the Cape Colony to Bulawayo in Southern Rhodesia.
  • The Mashonaland Railways (MR) that operated in Southern Rhodesia from Bulawayo to Umtali in the east.
  • The Rhodesia Railways Northern Extensions (RRM) that operated north and east of Bulawayo towards Northern Rhodesia.
  • The Beira and Mashonaland and Rhodesia Railways (BMR) that operated between Umtali in Southern Rhodesia and Beira in Mozambique.

Manufacturers[edit]

The fifty-two locomotives were ordered in five batches from three British manufacturers.[1]

  • Twelve were delivered by Neilson, Reid and Company between August and October 1899. They were virtually identical to the ex CGR Class 7A. Two of them were numbered BR7 and BR8 for the BMR, for service at the Beira end, while the rest were numbered in the range from RR1 to RR10. In 1901 eleven of them were renumbered in the range from MR8 to MR18, MR20 and MR21, not in order, for the BMR. The exception was no. RR8, which was delivered damaged beyond local repair abilities, apparently as a result of hostilities while in transit through the area under control of the British Military near Mafeking. A Neilson, Reid built 7th Class locomotive of the Imperial Military Railways (IMR), number IMR 110, was subsequently transferred to the BMR at Umtali in March 1901 as replacement for the damaged no. RR8. It was renumbered to MR19, the number that would have been allocated to no. RR8. The renumberings are tabled below.[1]
  • A second batch of twelve were delivered by Neilson, Reid in August 1900 and numbered in the range from RR11 to RR22. They were placed in service on the line from Vryburg to Bulawayo and based at Mafeking. In 1901 four of them, no. RR11, RR12, RR17 and RR20, were relocated to the BMR and renumbered in the range from MR20 to MR23, in order. Many of the Neilson, Reid built locomotives from both batches were renumbered a second time in 1906, as shown in the table.[1]
  • A third batch of eight locomotives was delivered from Kitson and Company between 1901 and 1903, numbered in the range from RR23 to RR30. These were built with Belpaire fireboxes instead of the usual round-topped fireboxes that earlier 7th Class locomotives of the CGR, the IMR and the RR were delivered with. They were also placed in service at Mafeking.[1]
  • The fourth batch of ten locomotives, again with Belpaire fireboxes, was delivered from North British Locomotive Company (NBL) in October and November 1903. They were numbered in the range from RR31 to RR40. Of these, numbers RR31 to RR38 were allocated to the Mashonaland Railways-Kalomo-Broken Hill (MR-KB) section. They retained their RR numbers, but had brass plates with the letters "KB" affixed above their number plates on their cab sides to indicate their ownership. The other two were also placed in service at Mafeking.[1]
  • The fifth and final batch of ten Rhodesian 7th Class locomotives was also built by NBL and delivered in November and December 1903, numbered in the range from RR41 to RR50. They were also placed in service at Mafeking.[1]

Works numbers[edit]

Their builders, works numbers and renumberings are shown in the table.[1][3][4][6]

South African Railways[edit]

In May 1915 six of the Neilson, Reid built 7th Class locomotives were purchased by the South African Railways (SAR) to augment its locomotive stock, which was being severely taxed due to war conditions at the time. These six locomotives included the war-damaged no. RR8 that had still not been repaired and consequently never ran a mile in revenue service in Rhodesia, as well as the ex IMR locomotive that had been transferred to Rhodesia as compensation for the damaged no. RR8. They were renumbered and five of them were classified to SAR Class 7D, numbered in the range from 1351 to 1355, and one was mistakenly classified as Class 7B, number 949.[1][6][8]

Classification errors[edit]

During this SAR classification and renumbering process, two of these locomotives were incorrectly classified, possibly as a result of their records getting exchanged in an apparent administrative error.[9]

  • Ex IMR no. 110, that replaced the damaged no. RR8, would have become Central South African Railways (CSAR) no. 380 in 1902 and, with the rest of the ex IMR locomotives, would have been designated SAR Class 7B in 1912, but this never happened since it had already been transferred to the BMR at Umtali in March 1901. When it was taken onto the SAR roster from Rhodesia in 1915, it was incorrectly designated as Class 7D instead of Class 7B and renumbered SAR no. 1355.[1][9]
  • Ex no. RR1, later no. MR8 and then no. RRM63 was incorrectly designated as Class 7B instead of Class 7D and renumbered SAR no. 949.[1][6]

Class 7 sub-classes[edit]

Other 7th Class locomotives that came onto the SAR roster from the other Colonial railways in the region in 1912, namely the CGR, CSAR, the Natal Government Railways (NGR) and, in 1925, from the New Cape Central Railways (NCCR), were grouped into six different sub-classes by the SAR, becoming SAR Classes 7, 7A to 7C, 7E and 7F.[7]

Modifications[edit]

During the 1930s many of the Class 7 family of locomotives were equipped with superheated boilers and piston valves. On the Class 7B and Class 7C this conversion was sometimes indicated with an "S" suffix to the class letter on the locomotive number plates, but on the rest of the Class 7 family this distinction was not applied consistently. The superheated versions could be identified by the position of the chimney on the smokebox, with the chimney displaced forward to provide space behind it in the smokebox for the superheater header.[7][8]

Service[edit]

In SAR service, the Class 7 series did duty on every system in the country. During the South West African Campaign in World War I, twenty-nine Class 7 to Class 7C locomotives were sent to South West Africa (SWA) to assist the expeditionary forces. They proved so successful in that territory that more were gradually transferred there in later years. By the time the Class 24 arrived in SWA in 1949, there were still altogether fifty-three Class 7 series locomotives in use there. Most remained there and were only transferred back to South Africa when the Class 32-000 diesel-electric locomotives replaced them in 1961. In South Africa they remained in branchline service, particularly at Tarkastad and Ladysmith and also as the "Makadas" on the line from Touws River to Ladismith, until they were finally withdrawn in 1972.[1][8]

See also[edit]

References[edit]

  1. ^ a b c d e f g h i j k l m n o p q Pattison, R.G. (1997). The Cape Seventh Class Locomotives (1st ed.). Kenilworth, Cape Town: The Railway History Group. pp. 10–12, 25–33. ISBN 0958400946. 
  2. ^ Neilson, Reid works list, compiled by Austrian locomotive historian Bernhard Schmeiser
  3. ^ a b Pattison, R.G. (2005). Thundering Smoke, (1st ed.). Ilminster, Somerset: Sable Publishing House. pp. 42-48. ISBN 0-9549488-1-5.
  4. ^ a b Durrant, A.E. (1997). The Smoke that Thunders, (1st ed.). Harare: African Publishing Group. ISBN 1-77901-134-2.
  5. ^ North British Locomotive Company works list, compiled by Austrian locomotive historian Bernhard Schmeiser
  6. ^ a b c d e f Holland, D.F. (1972). Steam Locomotives of the South African Railways, Volume 2: 1910-1955 (1st ed.). Newton Abbott, Devon: David & Charles. pp. 32–33. ISBN 978-0-7153-5427-8. 
  7. ^ a b c South African Railways and Harbours Locomotive Diagram Book, 2’0” & 3’6” Gauge Steam Locomotives, 15 August 1941, as amended
  8. ^ a b c d e Paxton, Leith; Bourne, David (1985). Locomotives of the South African Railways (1st ed.). Cape Town: Struik. pp. 46–48. ISBN 0869772112. 
  9. ^ a b Holland, D.F. (1971). Steam Locomotives of the South African Railways, Volume 1: 1859-1910 (1st ed.). Newton Abbott, Devon: David & Charles. pp. 123–124. ISBN 978-0-7153-5382-0.