Rhodesia Railways 20th class

Rhodesia Railways 20th class
Zambia Railways 20th class
National Railways of Zimbabwe 20th class

NRZ 20A class No. 747, at the coal stage, Dete, July 1990
Type and origin
Power type Steam
Builder Beyer, Peacock and Company
Build date 1954–1958
Total produced 61
Specifications
Configuration 4-8-2+2-8-4
UIC class (2′D1′)(1′D2′) h4t
Gauge 3 ft 6 in (1,067 mm) Cape gauge
Driver dia. 51 in (1,295 mm)
Length 103 ft 2 in (31.45 m)
Fuel type Coal
Firebox:
 • Firegrate area		 63 sq ft (5.9 m2)
Boiler pressure 200 psi (1.38 MPa)
Heating surface 3,025 sq ft (281.0 m2)
 • Tubes and flues 2,790 sq ft (259 m2)
 • Firebox 235 sq ft (21.8 m2)
Superheater:
 ​
 • Heating area 750 sq ft (70 m2)
Cylinders Four
Cylinder size 20 in × 26 in (508 mm × 660 mm)
Train brakes Vacuum
Career
Operators Rhodesia Railways
Zambia Railways
National Railways of Zimbabwe
Class 20th, 20A
Numbers RR: 700–760
NRZ: 730–737, 740–750
Withdrawn 1970–1992

The Rhodesia Railways 20th class, later Zambia Railways and National Railways of Zimbabwe 20th classes, were among the largest and most powerful steam locomotives in the southern hemisphere.

With 61 locomotives built, they were the fourth largest class of Garratt locomotive built – after the South African Railways class GMA, (120), the Rhodesia Railways 15th class, (74) and the South African Railways class GF (65).

Design

The locomotives have a 4-8-2+2-8-4 of "Double Mountain" wheel arrangement. This arrangement was also used by most other large Garratts.

The 20th class was the first and only class of Rhodesia Railways locomotives to be fitted with mechanical stokers. Other technical features included bar frames and thermic syphons.

The later locomotives were classified as 20A class; the main difference being that the 20ths' inside and outside trailing wheels were of the same size, on the 20A, the inside trailing wheels diameter had been increased in size. The 20As were also heavier.

The 20th class also had the round-ended bunkers characteristic of late Garratts.

Table of 20th and 20A class orders
Year Qty BP Order No. BP Works No. RR Class RR No. Notes
1954 15 11166 7685–7699 20th 700–714
1957 6 11182 7780–7785 20th 715–720
1957 9 11182 7786–7794 20A 721–729
1957 15 11183 7795–7809 20A 730–744
1957–58 16 11184 7810–7825 20A 745–760

The early years

The initial use of the 20th class was ill-fated. The locomotives were plagued with teething troubles including cracks in the locomotives' frames and fireboxes. Unlike the South African Railways' GMA, which had cast steel frames, the 20th had conventional fabricated bar frames.

Two locomotives were scrapped very early due to accident damage. Strangely, they were the first (700) and the last (760) built.

Apart from these problems, the locomotives met all expectations. They were by far the most powerful locomotives on the Rhodesia Railways, and were rated to pull 1,250 long tons (1,270 t) up a 1.55% (1 in 64) incline.

Later service

In 1964, Zambia took over the operation of railways in its territory. This included the transfer of 80–90 locomotives[1] – about half of them 20th and 20A class locomotives. This left only fifteen 20ths in [Southern] Rhodesia. They later re-acquired four from Zambia Railways when the latter dieselised.[2]

These nineteen locomotives were 705, 707, 709, 710, 714, 716, 717 and 718 (20th) and 723, 724, 726, 727, 729, 738, 746, 747, 749, 753 and 756 (20A) were mainly used in the transportation of coal between Thomson Junction to Bulawayo and Victoria Falls. On this route they were rated with a maximum load of 1,600 long tons (1,630 t).[1]

In Zambia, the 20th class was replaced by diesels and retired by about 1970.

By June 1975, there were only 18 in service in Rhodesia, all allocated to Bulawayo.[1]

Rebuilding

In 1978 Rhodesia Railways started a rebuilding program for its steam locomotive fleet. Between 1980 and 1983 the remaining Garratt locomotives were completely overhauled and had some modernisation, including the installation of roller bearings. The work was undertaken by private companies, especially the RESSCO works in Bulawayo.

Work on the first two was completed in 1980, although it was April 1983 before they were all dealt with.

As part of the rebuilding programme, the locomotives' running numbers were consolidated into two blocks: 730–737 (20th) and 740–750 (20A). Three locomotives kept their old numbers: 746, 747, and 749. At the same time, the locomotives received names; the cast nameplate were applied to the cabside above the numberplate.[3]

Post rebuilding service

All the rebuilt 20th and 20A locomotives were allocated to Bulawayo.

Due to the continuing difficult economic situation in Zimbabwe, the rebuilt steam locomotives remained in service longer than originally planned. Finally, in the early 1990s, new diesels were ordered and the locomotives were systematically withdrawn as they became due for general overhaul. All were withdrawn from general service by 1994.

All those allocated to Bulawayo with the exception of 730/736/740/749 were then put up for tender and scrapped.

Fate

Some locomotives are preserved in museums or plinthed as monuments.

Key: Status unknown Out of service Preserved Scrapped
Roster of 20th and 20A class locomotives in 1994
RR/ZR
No. 		NRZ
No. & Name 		Fate
700 — Scrapped after an accident in the 1950s
702 — Ndola locomotive scrap line.[4]
703 — Lusaka, locomotive scrap line[4][5]
704 — Lusaka, locomotive scrap line[4][5]
705 730 Insuga Bulawayo Railway Museum (probably the best preserved example)
707 731 Stored, Bulawayo depot
708 — Livingstone Railway Museum
709 732 Stored, Bulawayo depot
710 733 Stored, Bulawayo depot
714 734 Stored, Bulawayo depot
716 735 Stored, Bulawayo depot
717 736 Enxa Stored, Bulawayo depot (was in the Museum until 2004)
718 737 Incubo Stored, Bulawayo depot
721 — ZCCM copper mine in Mufulira (unknown condition)
723 740 Ingwezi[3] Stationary boiler, Bulawayo (was operational museum locomotive until 2001 – now had cylinder damage)
724 741 Bubi Stored, Bulawayo depot
726 742 Gwaai[3] Stored, Bulawayo depot
727 743 Stored, Bulawayo depot
728 — One of the locomotives used in 1980 (whereabouts unknown)
729 744 Stored, Bulawayo depot
733 — Lusaka, locomotive scrap line[4][5]
735 — Ndola, locomotive scrap line[4]
738 745 Stored, Bulawayo depot
740 — Ndola, locomotive scrap line[4]
741 — Plinthed at Ndola station[4]
746 746 Stored, Bulawayo depot
747 747 Jumbo[6] Stored, Bulawayo depot
748 — Ndola, locomotive scrap line[4]
749 749 Umzingwane Stored, Bulawayo depot
753 748 Lukozi[7] Stored, Bulawayo depot
755 — In service until at least 1971,[8] whereabouts unknown
756 750 Bembezi [9] Stored, Bulawayo depot
758 — Plinthed in Kitwe station[4]
760 — Scrapped after an accident in the 1950s

References

  1. 1 2 3 Turk 1976, p. 76
  2. ↑ Here Durrant gives 14 +4, totalling 18; but 19 units are listed. It could therefore have been 14+5 locomotives.
  3. 1 2 3 Eatwell 2011, p. 517
  4. 1 2 3 4 5 6 7 8 9 Photos of dumped locomotives in Zambia
  5. 1 2 3 15°24′39.26″S 28°16′57.38″E / 15.4109056°S 28.2826056°E
  6. ↑ Eatwell 2011, p. 518
  7. ↑ Eatwell 2011, p. 521
  8. ↑ Photograph of No. 755 in 1971
  9. ↑ Eatwell 2011, p. 590

External links

External video
Zimbabwe Steam: Bulawayo - Garratt City #1 - April 1997 A few scenes of Bulawayo in 1997 with Classes 14A, 15A and 16A Garratts at work on various duties around the city, along with shed and workshop scenes. (Time 12:16)
External video
Zimbabwe Steam: Bulawayo - Garratt City #2 - April 1997 Some morning scenes at Bulawayo Steam Shed in 1997 with 14A, 15A and 16A Garratts leaving the shed. Then we see 15A 417 "Umathebene" hauling a goods train out to Cement and shunting the yard there. (Time 5:38)
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