| CGR 8th Class 4-8-0 1904 South African Classes 8F & 8FW 4-8-0 | |
| Hatnote: | ♠ Original locomotive, as built Superheated, inside admission valves, Class 8FW |
| Powertype: | Steam |
| Designer: | Cape Government Railways (H.M. Beatty) |
| Builder: | North British Locomotive Company |
| Serialnumber: | 16161-16170 |
| Buildmodel: | CGR 8th Class (4-8-0) |
| Builddate: | 1904 |
| Totalproduction: | 10 |
| Whytetype: | 4-8-0 (Mastodon) |
| Uicclass: | ♠ 2'Dn2 - 2'Dh2 |
| Driver: | 2nd coupled axle |
| Leadingdiameter: | NaN0NaN0 |
| Coupleddiameter: | 480NaN0 |
| Tenderdiameter: | NaN0NaN0 as built 340NaN0 retyred |
| Wheelbase: | 46feet |
| Engine Total: | 23feet |
| Leading: | 60NaN0 |
| Coupled: | 13feet |
| Tender Total: | 14feet |
| Tenderbogie: | 4feet |
| Over Couplers: | 54feet |
| Height: | ♠ 12feet |
| Frametype: | Bar |
| Axleload: | ♠ 11lt 12lt |
| Leadingbogie/Pony: | ♠ 12lt 12lt |
| Coupled All: | ♠ 11lt |
| Coupled 1: | 11lt |
| Coupled 2: | 12lt |
| Coupled 3: | 11lt |
| Coupled 4: | 11lt |
| Tenderbogieload: | Bogie 1: 20lt Bogie 2: 22lt |
| Tenderaxle: | 11lt |
| Weightondrivers: | ♠ 46lt 48lt |
| Locoweight: | ♠ 59lt 61lt |
| Tenderweight: | 43lt |
| Locotenderweight: | ♠ 102lt 104lt |
| Tendertype: | XF (2-axle bogies) XC, XC1, XD, XE, XE1, XF, XF1, XF2, XJ, XM, XM1, XM2, XM3 permitted |
| Fueltype: | Coal |
| Fuelcap: | 101NaN1 |
| Watercap: | 3000sigfig=3NaNsigfig=3 |
| Fireboxtype: | Round-top |
| Firearea: | ♠ 21.35square feet 21square feet |
| Pitch: | ♠ 7feet |
| Diameterinside: | ♠ 50NaN0 |
| Lengthinside: | ♠ 11feet 11feet |
| Smalltubediameter: | ♠ 205: 20NaN0 115: 20NaN0 |
| Largetubediameter: | 18: NaN0NaN0 |
| Boilerpressure: | ♠ 1800NaN0 |
| Safetyvalvetype: | Ramsbottom |
| Totalsurface: | ♠ 1320.6square feet 1081square feet |
| Tubearea: | ♠ 1184square feet 950square feet |
| Fireboxarea: | ♠ 136.6square feet 131square feet |
| Superheaterarea: | 214square feet |
| Cylindercount: | Two |
| Cylindersize: | ♠ NaN0NaN0 bore 200NaN0 bore ♠ 240NaN0 stroke |
| Valvegear: | Stephenson |
| Valvetype: | ♠ Slide - Piston |
| Coupling: | Johnston link-and-pin AAR knuckle (1930s) |
| Tractiveeffort: | ♠ 23110lbf @ 75% 27000lbf @ 75% |
| Operator: | Cape Government Railways South African Railways |
| Operatorclass: | CGR 8th Class SAR Classes 8F & 8FW |
| Numinclass: | 10 |
| Fleetnumbers: | CGR 829-838 SAR 1234-1243 |
| Deliverydate: | 1904 |
| Firstrundate: | 1904 |
| Withdrawndate: | 1972 |
| Notes: | The leading coupled axle had flangeless wheels |
The South African Railways Class 8F 4-8-0 of 1904 was a steam locomotive from the pre-Union era in the Cape of Good Hope.
In 1904, the Cape Government Railways placed its final batch of ten 8th Class Mastodon type steam locomotives in service. In 1912, when they were assimilated into the South African Railways, they were renumbered and designated Class 8F.[1]
The first 8th Class locomotive of the Cape Government Railways (CGR) was a Consolidation type designed by H.M. Beatty, the CGR's Chief Locomotive Superintendent from 1896 to 1910. It was later to become the Class 8X on the South African Railways (SAR). While these first Schenectady- and ALCO-built locomotives were being subjected to exhaustive testing on all types of traffic and under varying conditions, some trouble was experienced with the leading two-wheeled pony truck. When designs were prepared at Salt River for a later order for more locomotives, the pony truck was replaced with a four-wheeled bogie.
Orders for the last 8th Class locomotives for the CGR were placed with the North British Locomotive Company (NBL) in 1903. The ten locomotives were built and delivered in 1904, numbered in the range from 829 to 838 and allocated to the Western System of the CGR.[2]
These ten locomotives were the final batch of CGR 8th Class locomotives to be built with a Mastodon type wheel arrangement.
They were delivered with Type XF tenders with a coal capacity of 101NaN1, a water capacity of 3000impgal and a maximum axle load of 11lt.[3] [4]
When the Union of South Africa was established on 31 May 1910, the three Colonial government railways (CGR, Natal Government Railways and Central South African Railways) were united under a single administration to control and administer the railways, ports and harbours of the Union. Even though the South African Railways and Harbours came into existence in 1910, the actual classification and renumbering of all the rolling stock of the three constituent railways was only implemented with effect from 1 January 1912.[1] [5]
In 1912, these ten locomotives were renumbered in the range from 1234 to 1243 and designated Class 8F.
These locomotives, together with the rest of the CGR's 8th Class Consolidations and Mastodons and the Classes 8-L1 to 8-L3 Mastodon locomotives from the Central South African Railways (CSAR), were grouped into ten different sub-classes by the SAR. The locomotives were designated SAR Classes 8 and 8A to 8F and the locomotives were designated Classes 8X to 8Z.[3] [4]
During A.G. Watson's term as Chief Mechanical Engineer of the SAR from 1929 to 1936, many of the Classes 8 to 8F locomotives were equipped with superheated boilers, larger bore cylinders and either inside or outside admission piston valves. The outside admission valve locomotives had their cylinder bore increased from NaNto and retained their existing SAR classifications, while the inside admission valve locomotives had their cylinder bore increased to 200NaN0 and were reclassified by having a "W" suffix added to their existing SAR classifications.[3] [4]
Of the Class 8F locomotives, numbers 1236, 1242 and 1243 were equipped with superheated boilers, 200NaN0 bore cylinders and inside admission piston valves, and reclassified to Class 8FW.[3] [4]
In SAR service, the Class 8 family of locomotives worked on every system in the country and, in the 1920s, became the mainstay of motive power on many branchlines. Their final days were spent in shunting service. They were all withdrawn from service by 1972.
Class 8FW no. 1236 is preserved and plithed at De Aar. It is the sole surviving Class 8F in South Africa.