South African Class 17 4-8-0TT explained

South African Class 17 4-8-0TT
Powertype:Steam
Designer:Natal Government Railways
(William Milne)
Builder:Dübs and Company
South African Railways
Serialnumber:See table
Buildmodel:SAR Class 17
Builddate:1926-1929
Totalproduction:21
Whytetype:4-8-0TT (Mastodon)
Uicclass:2’Dn2t
Driver:2nd coupled axle
Leadingdiameter:NaN0NaN0
Coupleddiameter:390NaN0
Tenderdiameter:340NaN0
Wheelbase:44feet
Engine Total:19feet
Leading:50NaN0
Coupled:110NaN0
Tender Total:16feet
Tenderbogie:4feet
Over Couplers:52feet
Height:12feet
Frametype:Plate
Axleload:8lt
Leadingbogie/Pony:9lt
Coupled 1:8lt
Coupled 2:8lt
Coupled 3:8lt
Coupled 4:8lt
Tenderbogieload:Bogie 1: 16lt
Bogie 2: 17lt
Weightondrivers:32lt
Locoweight:42lt
Tenderweight:34lt
Locotenderweight:76lt
Tendertype:2-axle bogies or 3-axle
Fueltype:Coal
Fuelcap:5lt
Watercap:1358sigfig=3NaNsigfig=3 engine
Tendercap:2600sigfig=3NaNsigfig=3 tender
Fireboxtype:Belpaire
Firearea:24square feet
Pitch:70NaN0
Diameterinside:3feet
Lengthinside:10feet
Smalltubediameter:187: NaN0NaN0
Boilerpressure:1600NaN0
Safetyvalvetype:Ramsbottom
Totalsurface:992square feet
Tubearea:930square feet
Fireboxarea:62square feet
Cylindercount:Two
Cylindersize:170NaN0 bore
210NaN0 stroke
Valvegear:Stephenson
Valvetype:Slide
Coupling:Johnston link-and-pin
AAR knuckle (1930s)
Tractiveeffort:18670lbf @ 75%
Operator:South African Railways
Operatorclass:Class 17
Numinclass:21
Fleetnumbers:1415–1435
Deliverydate:1926-1929
Firstrundate:1926
Withdrawndate:1961
Notes:The leading coupled axle had flangeless wheels

The South African Railways Class 17 4-8-0TT of 1926 was a steam locomotive from the pre-Union era in the Natal Colony.

Between 1926 and 1929, to address a shortage of suitable shunting locomotives, the South African Railways rebuilt twenty-one Class A 4-8-2 Mountain type tank steam locomotives to Class 17 4-8-0 Mastodon type tank-and-tender locomotives.[1] [2] [3]

Manufacturers

The Natal Government Railways (NGR) Class D 4-8-2T Mountain type tank locomotive was designed by William Milne, the locomotive superintendent of the NGR from 1877 to 1896, and built by Dübs and Company. One hundred of these locomotives were delivered in ten batches by Dübs between 1888 and 1899 and in 1915 another two were built from spare parts by the South African Railways (SAR) in their Durban shops.[1]

Belpaire firebox

Beginning in 1905, these NGR Class D locomotives, originally known on the NGR as the "Dübs A", were gradually reboilered and fitted with Belpaire fireboxes with wider firegrates. The unmodified locomotives were then designated NGR Class D1 while the modified locomotives with Belpaire fireboxes were designated Class D2.[1] [4]

In SAR service, the NGR Class D1 and D2 were both designated Class A in 1912 while the modified locomotives were referred to as Class A Belpaire.[1]

Rebuilding

When a shortage of suitable shunting locomotives developed in the 1920s as a result of increasing traffic throughout the country and particularly on the Witwaters­rand, the SAR modified twenty-one of the Class A Belpaire Mountain type tank loco­mo­tives.[1] [3]

The modifications were done between 1926 and 1929 and consisted of the removal of their trailing bissel bogies and coal bunkers, the shortening of their main frames and the addition of tenders to increase their coal and water capacity, thereby converting them to 4-8-0 Mastodon type tank-and-tender locomotives.[1] [3]

Tenders from various scrapped locomotive types were used. The tender depicted in the main picture is a three-axle tender while the official SAR locomotive diagram depicts a tender with four axles on two bogies.[1] [2]

Service

These rebuilt 4-8-2TT locomotives were reclassified to and renumbered in the range from 1415 to 1435. They were employed as shunting engines around Durban, Pietermaritzburg and Port Elizabeth and gave more than thirty years service in this format. In October 1957 Pietermaritzburg’s last two Class 17s were transferred from Masons Mill to Greyville near Durban. The locomotives were all withdrawn from service by 1961, more than seventy years after the first Class A locomotive was built.[3] [5]

In November 1953 two of these locomotives, numbers 1423 and 1431, were purchased by the Zambezi Saw Mills Company for use on their Livingstone-Mulobezi logging railway in Northern Rhodesia. These two engines were scrapped between 1961 and 1963.

Works numbers and renumbering

Notes and References

  1. Espitalier, T.J.; Day, W.A.J. (1944). The Locomotive in South Africa - A Brief History of Railway Development. Chapter III - Natal Government Railways. (Continued). South African Railways and Harbours Magazine, June 1944. p. 423.
  2. South African Railways and Harbours Locomotive Diagram Book, 2'0" & 3'6" Gauge Steam Locomotives, 15 August 1941, pp. 21 & 21A, as amended
  3. https://sites.google.com/site/soulorailway/home/system-6-1/part-2-greyville-loco-greyville-station-to-umgeni-and-berea-road-to-rossburgh Soul of A Railway, System 6, Part 2: Greyville Loco, Greyville Station to Umgeni & Berea Road to Rossburgh. Caption 7.
  4. The Railway Report for year ending 31 Dec. 1908, Natal Government Railways, p. 39, par 14.
  5. https://sites.google.com/site/soulorailway/home/system-6-1/the-new-main-line-from-rossburgh-to-pietermaritzburg Soul of A Railway, System 6, Part 5: The New Main Line from Rossburgh to Pietermaritzburg compiled by Les Pivnic. Caption 103.