South African Class 16DA 4-6-2 1928

The South African Railways Class 16DA 4-6-2 of 1928 was a steam locomotive.

South African Class 16DA 4-6-2 1928
Hohenzollern-built no. 870, 4 April 1979
Type and origin
♠ With 60 inch (1,524 mm) coupled wheels
With 63 inch (1,600 mm) coupled wheels
22x26 Cylinders – 23x26 Cylinders
Power typeSteam
DesignerSouth African Railways
(Col F.R. Collins DSO)
BuilderHohenzollern Locomotive Works
Baldwin Locomotive Works
Serial numberHohenzollern 4653-4658
Baldwin 60820-60827
ModelClass 16DA
Build date1928-1929
Total produced14
Specifications
Configuration:
 • Whyte4-6-2 (Pacific)
 • UIC2'C1'h2
Driver2nd coupled axle
Gauge3 ft 6 in (1,067 mm) Cape gauge
Leading dia.30 in (762 mm)
Coupled dia.♠ 60 in (1,524 mm)
63 in (1,600 mm)
Trailing dia.33 in (838 mm)
Tender wheels34 in (864 mm)
Wheelbase60 ft 3+316 in (18,369 mm) ​
 • Engine30 ft 8 in (9,347 mm)
 • Leading6 ft 10 in (2,083 mm)
 • Coupled11 ft (3,353 mm)
 • Tender20 ft 5 in (6,223 mm)
 • Tender bogie6 ft 2 in (1,880 mm)
Length:
 • Over couplers68 ft 4+316 in (20,833 mm)
Height♠ 12 ft 10 in (3,912 mm)
12 ft 11+12 in (3,950 mm)
Frame typeBar
Axle load♠ 18 LT 15 cwt (19,050 kg)
19 LT 2 cwt (19,410 kg) ​
 • Leading 18 LT 10 cwt (18,800 kg)
 • Coupled♠ 18 LT 15 cwt (19,050 kg)
 • 1st coupled 19 LT 2 cwt (19,410 kg)
 • 2nd coupled 19 LT (19,300 kg)
 • 3rd coupled 19 LT 2 cwt (19,410 kg)
 • Trailing 14 LT 17 cwt (15,090 kg)
 • Tender bogieBogie 1: 33 LT 18 cwt (34,440 kg)
Bogie 2: 35 LT 10 cwt (36,070 kg)
 • Tender axle17 LT 15 cwt (18,030 kg)
Adhesive weight♠ 56 LT 5 cwt (57,150 kg)
57 LT 4 cwt (58,120 kg)
Loco weight♠ 89 LT 12 cwt (91,040 kg)
90 LT 11 cwt (92,000 kg)
Tender weight69 LT 8 cwt (70,510 kg)
Total weight♠ 159 LT (161,600 kg)
159 LT 19 cwt (162,500 kg)
Tender typeKT (2-axle bogies)
Fuel typeCoal
Fuel capacity14 LT (14.2 t)
Water cap.6,000 imp gal (27,300 L)
Firebox:
 • TypeRound-top
 • Grate area45 sq ft (4.2 m2)
Boiler:
 • Pitch♠ 8 ft 6 in (2,591 mm)
8 ft 7+12 in (2,629 mm)
 • Diameter5 ft 10+14 in (1,784 mm)
 • Tube plates17 ft 10+58 in (5,451 mm)
 • Small tubes181: 2 in (51 mm)
 • Large tubes30: 5+38 in (137 mm)
Boiler pressure♠ 195 psi (1,344 kPa)
205 psi (1,413 kPa)
Safety valvePop
Heating surface:
 • Firebox164 sq ft (15.2 m2)
 • Tubes2,453 sq ft (227.9 m2)
 • Arch tubes22 sq ft (2.0 m2)
 • Total surface2,639 sq ft (245.2 m2)
Superheater:
 • Heating area593 sq ft (55.1 m2)
CylindersTwo
Cylinder size 22 in (559 mm) bore
23 in (584 mm) bore
26 in (660 mm) stroke
Valve gearWalschaerts
Valve typePiston
CouplersAAR knuckle
Performance figures
Tractive effort 30,670 lbf (136.4 kN) @ 75%
33,530 lbf (149.1 kN) @ 75%
30,710 lbf (136.6 kN) @ 75%
33,570 lbf (149.3 kN) @ 75%
Career
OperatorsSouth African Railways
ClassClass 16DA
Number in class14
Numbers843-850 & 868-873
Delivered1928-1929
First run1928
Withdrawn1973

In 1928, the South African Railways placed six Class 16DA steam locomotives with a 4-6-2 Pacific type wheel arrangement in passenger train service. Eight more entered service in 1929.[1][2]

Manufacturers

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Further orders for locomotives similar to the Class 16D Pacific type locomotive were placed for the South African Railways (SAR) in 1928. The design of the earlier engines was modified by the Chief Mechanical Engineer (CME), Colonel F.R. Collins DSO, along the same lines as his design of the Class 15CA Mountain type.[1][2][3]

 
Col F.R. Collins DSO

This consisted of a locomotive bar frame which was shorter to end at the front of the firebox, with a bridle casting to create a widened frame extension below the firebox and the cab to the rear dragbox to gain more ashpan room under the firebox.[1][2]

These redesigned locomotives were designated Class 16DA and were built by two manufacturers in 1928 and 1929. The first six, numbered in the range from 868 to 873, were built in Germany by Hohenzollern Locomotive Works and entered service in 1928. Another eight locomotives, numbered in the range from 843 to 850, were built in the United States of America by Baldwin Locomotive Works and entered service in 1929.[1][2]

Characteristics

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The Hohenzollern and Baldwin-built Class 16DA locomotives basically differed from the predecessor Class 16D only by virtue of its shortened frame and bridle casting, the Class 16D having had a frame extending all the way from the front buffer beam to the rear dragbox. They used the same Type KT tenders with a coal capacity of 14 long tons (14.2 tonnes) and a water capacity of 6,000 imperial gallons (27,300 litres). As delivered, they had 60 inches (1,524 millimetres) diameter coupled wheels and their cylinders were of 22 inches (559 millimetres) bore and 26 inches (660 millimetres) stroke. Their boiler operating pressure was set at 195 pounds per square inch (1,344 kilopascals).[2][3]

Modification

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During the 1940s six of these locomotives, three from each manufacturer group, were retyred with 63 inches (1,600 millimetres) diameter tyres on their coupled wheels. To not have their tractive effort reduced by the larger coupled wheels, their cylinders were reamed from a bore of 22 to 23 inches (559 to 584 millimetres) and their operating boiler pressure was raised to 205 pounds per square inch (1,410 kilopascals). All the modified locomotives remained classified as Class 16DA.[4][5]

When the larger tyres were fitted, the old tyres were left in position and turned down on the wheel centres to serve as liners and the new tyres were then shrunk on over the liners. The practice of increasing the diameter of coupled wheels, wheel spacing and other considerations permitting, was begun by A.G. Watson during his term in office as CME and was continued by his successors. The reduction of tractive effort caused by the larger wheels was made up by increasing boiler pressures or by fitting larger cylinders or both, as required. This policy resulted in more mileage between heavy repairs, less cost-per-mile on repairs and locomotives capable of higher speeds.[2]

Service

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The Class 16DA Pacifics were initially placed in passenger service between Johannesburg and Kimberley where they regularly worked trains like the Union Express and Union Limited, which became the Blue Train after the Second World War. From 1930 the new Henschel-built wide-firebox Class 16DA took over this duty.[6][7]

 

In 1939–1940, when new air-conditioned rolling stock was placed in service on the Union Limited and Union Express services between Cape Town and Johannesburg, all the Class 16DA and Class 16E locomotives were transferred to Bloemfontein in the Orange Free State. From here, they continued to work passenger trains north and south, including the Orange Express, until the Class 15F replaced them and they were relegated to suburban and local passenger train work. By the early 1950s, the suburban trains to Lynchfield and Melorane were handled by narrow-firebox Class 16DA locomotives which only occasionally worked mainline passenger trains by then. They were withdrawn from service in 1973.[6][8]

Four of the Baldwin-built locomotives were sold into industrial service. No. 844 went to Hlobane Colliery in Natal and later to Umgala Colliery. Numbers 845, 847 and 848 went to Wankie Colliery in Rhodesia, where they became numbers 5 to 7 in reverse order. After they were finally withdrawn in 1982, one of these three was plinthed alongside the main North road at Hwange. Another of the Baldwin-built locomotives, no. 850, is plinthed at Theunissen in the Free State.[3]

Works numbers

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The table lists the Hohenzollern and Baldwin Class 16DA engine numbers, builders, years built, works numbers and variations in coupled wheel sizes.[4][5]

Preservation

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Number Works nmr THF / Private Leaselend / Owner Current Location Outside SOUTH AFRICA ?
848 Private Wanki Collery Main Street Zimbabwe next to Wanki Highway
850 Private Theunissen Municipality Main Street
870 THF Krugersdorp Locomotive Depot
876 THF Transnet Heritage Foundation (Museum) Bloemfontein Locomotive Depot
878 THF Transnet Engineering Bloemfontein Locomotive Depot
879 THF Ceres Railway Company Cape Town Station

Illustration

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References

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  1. ^ a b c d Holland, D. F. (1972). Steam Locomotives of the South African Railways. Vol. 2: 1910-1955 (1st ed.). Newton Abbott, England: David & Charles. pp. 57–58. ISBN 978-0-7153-5427-8.
  2. ^ a b c d e f Espitalier, T.J.; Day, W.A.J. (1946). The Locomotive in South Africa – A Brief History of Railway Development. Chapter VII – South African Railways (Continued). South African Railways and Harbours Magazine, May 1946. pp. 375-376.
  3. ^ a b c Durrant, AE (1989). Twilight of South African Steam (1st ed.). Newton Abbott: David & Charles. p. 94. ISBN 0715386387.
  4. ^ a b South African Railways & Harbours/Suid Afrikaanse Spoorweë en Hawens (15 August 1941). Locomotive Diagram Book/Lokomotiefdiagramboek, 3'6" Gauge/Spoorwydte. SAR/SAS Mechanical Department/Werktuigkundige Dept. Drawing Office/Tekenkantoor, Pretoria. pp. 23-24.
  5. ^ a b South African Railways & Harbours/Suid Afrikaanse Spoorweë en Hawens (15 August 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, 23-24.
  6. ^ a b Paxton, Leith; Bourne, David (1985). Locomotives of the South African Railways (1st ed.). Cape Town: Struik. pp. 10–11, 67. ISBN 0869772112.
  7. ^ Soul of A Railway, System 7, Western Transvaal, based in Johannesburg, Part 26: Braamfontein West to Klerksdorp (home signal) by Les Pivnic, Part 1. Caption 18. (Accessed on 6 May 2017)
  8. ^ Soul of A Railway, System 5, Part 1: Bloemfontein. Caption 1. (Accessed on 1 March 2017)