South African Class 16C 4-6-2

The South African Railways Class 16C 4-6-2 of 1919 was a steam locomotive.

During 1919, the South African Railways placed ten Class 16C steam locomotives with a 4-6-2 Pacific type wheel arrangement in passenger train service. Another twenty entered service in 1922. Unlike the earlier Classes 16 and 16B, these locomotives had combustion chambers.^[1][2][3][4]

Manufacturer

The Class 16C 4-6-2 Pacific type locomotive was designed by D.A. Hendrie, Chief Mechanical Engineer (CME) of the South African Railways (SAR), and built by the North British Locomotive Company (NBL) in Glasgow, Scotland. Ten locomotives were delivered in 1919, numbered in the range from 812 to 821. A second order followed in 1921 for another twenty locomotives, which were numbered in the range from 822 to 841 when they were delivered in 1922.^[5]

Characteristics

D.A. Hendrie

They were identical to predecessors Classes 16 and 16B in most respects, except that Hendrie had added a combustion chamber to the boiler, similar to that of the Class 15A. This reduced the distance between tube plates from 18 feet 3 inches (5,563 millimetres) to 15 feet 10 ¹⁄₂ inches (4,839 millimetres). The presence of the combustion chamber was visible externally as an extension of the Belpaire firebox hump.^[2][5]

The engines were equipped with Lambert sanding gear, which was a "wet" system whereby a mixture of water and sand was delivered to the rails. Under ideal conditions with fine-grained sand, results were fairly good, but maintenance problems and cost led to reversion to gravity sanding on later engines.^[2]

Robinson superheater header

The boilers were fitted with the Robinson type superheater, the first time this type was used on a Hendrie engine. The Robinson header was constructed with compartments, alternately for saturated and super­heated steam. There were eight inlet and outlet ends of superheater elements expanded into the bottom wall of each compart­ment, with the exception of those compartments at each end, into which only three element ends were expanded. Three cover plates were bolted to the front of the header to allow access to the respective compartments, for expanding the element tubes in position or forcing them out when necessary.^[2]

Modifications

Coupled wheels

During 1937, the Class 16C engines were fitted with Stone-Deuta speed indicators. As built, the second coupled axle had flangeless wheels, but these were later retyred with flanges, with the object to obtain better distribution of tyre flange wear and improved running.^[2]

Like the subsequent Classes 16D and 16DA, the Class 16C locomotives were all delivered with 60 inches (1,524 millimetres) diameter coupled wheels. Their as-delivered boiler operating pressure was set at 190 pounds per square inch (1,310 kilopascals). During 1936, their coupled wheel diameter was enlarged to 63 inches (1,600 millimetres), similar to the modification which was also done on some Classes 16D and 16DA locomotives. In the process, their boiler operating pressure was raised to 200 pounds per square inch (1,380 kilopascals) in order to not have their tractive effort reduced by the larger coupled wheels.^[2][6][7]

Trofimoff piston valves

During 1931, A.G. Watson, CME of the SAR at the time, fitted engine no. 851 with Trofimoff type by-pass piston valves as an experiment. The Trofimoff valve was claimed to afford ideal conditions when drifting.^[2]

Trofimoff valve, closed

Trofimoff valve, open

It consisted of two fixed discs, secured to the valve spindle, and two junk rings, each carrying a Bull ring and four valve rings and both free to move longitudinally on the spindle. When the regulator is opened, steam forces the loose valve bodies against their respective fixed discs, and they then act as units similar to ordinary piston valves. When steam is shut off, the loose valve heads become detached from their respective discs and remain in their idle positions near the centre of the steam chest, while the valve spindle and fixed disks continue their reciprocating motion, with the spindle sliding freely through the now stationary loose valve heads, and with the steam and exhaust ports now in communication. With both ends of the cylinders now in communication, the use of ordinary by-bass or snifting valves became unnecessary.^[2]

Further similar experiments were carried out on Class 5B no. 726 in September 1931, Class 16B no. 805 in July 1932, Class 16DA no. 876 in August 1932, Class 15CA no. 2852 in March 1933 and finally on Class 15A no. 1961. The results of these extended tests did not prove entirely satisfactory and all these engines were gradually refitted with standard piston valves and snifting valves.^[2]

Watson Standard boilers

During the 1930s, many serving locomotives were reboilered with a standard boiler type, designed by A.G. Watson as part of his standardisation policy. Such Watson Standard reboilered locomotives were reclassified by adding an "R" suffix to their classification.^[5][6][7]

Eventually all thirty Class 16C locomotives were reboilered with Watson Standard no. 2B boilers and reclassified to Class 16CR. Several alterations to the engine frames were necessary to accommodate the no. 2B boiler. Bearing brackets had to be provided on the bridle casting to suit the firebox support sliding shoes, fitted at the front of the firebox foundation ring. The frame had to be altered to suit the new wider Watson cab, with its slanted front to allow access to the lagging which covered the flexible stays and stay caps on the firebox sides.^[2]

A steam operated firedoor was fitted, permitting the stoker to operate the door by means of a foot treadle, while an auxiliary operating handle allowed the driver to operate the door in situations where this was found more convenient. The ashpan was attached to the engine frame instead of to the boiler, to enable the boiler to be removed from the frame without disturbing the ashpan, an innovation which became standard practice on the SAR.^[2]

Their original Belpaire boilers were fitted with Ramsbottom safety valves, while the Watson Standard boiler was fitted with Pop safety valves. Early conversions were equipped with copper and later conversions with steel fireboxes. After reboilering, the main difference between the Class 16B and Class 16C, Hendrie's combustion chamber behind the Class 16C's boiler, disappeared and Class 16B locomotives which were reboilered with Watson Standard boilers were also reclassified to Class 16CR.^[5][6][7]

An obvious difference between an original and a Watson Standard reboilered locomotive is usually a rectangular regulator cover, just to the rear of the chimney on the reboilered locomotive. In the case of the Class 16C and Class 16CR, two even more obvious differences are the Watson cab and the absence of the Belpaire firebox hump between the cab and boiler on the reboilered locomotives.^[2][6][7]

Service

The Class 16C proved to be excellent locomotives which were popular with the locomotive crews, being free-steaming, fast, reliable, with quick acceleration and a reserve of power greater than that of either the Class 16 or Class 16B. On one occasion in 1922, one of them, working between Bloemfontein and Kroonstad, hauled a train of eighteen mainline saloons, a load which would have been considered good for the much more modern Class 15F of 1938.^[1][2]

South African Railways

The Class 16C Pacifics were placed in express passenger service, working out of Pretoria and Johannesburg, hauling all the important passenger trains of the time, such as the Natal mail train on the section between Johannesburg and Volksrust and the Cape mail train on the section between Johannesburg and Klerksdorp. When they were replaced by newer locomotives like the Class 16D, they were relegated to less glamorous passenger duties until, by the 1940s, they were in suburban and transfer service.^[1][5]

During the 1950s, some were relocated to Durban to assist the Class 14Rs on the South Coast line. When this line was electrified in 1967, they were again relocated, this time to Port Elizabeth, where they worked suburban trains to Uitenhage.^[5]

Others remained on the Witwatersrand, working the suburban to Springs and Nigel, double-heading with Class 15ARs on Pietersburg-bound trains out of Pretoria, as well as shunting and local pick-up duties. Some of their last passenger duties were on the Breyten line during 1967 and 1968.^[5]

They were sure-footed enough to take to shunting work as readily as to the fast passenger service which they were originally designed for, to the extent that some of their last duties at the Springs shed was to take over shunting duties from the Class S2 shunting locomotives. They were withdrawn from service between 1975 and 1976, with some being sold to start a second career in industrial service.^[4][5]

Industry

Two Class 16CRs, numbers 813 and 818, were sold to Dunn's Locomotive Works, to be employed at Delmas Colliery, and were at one time seconded to Durban Navigation Collieries (Durnacol) in Natal. No. 838 went to Klipfontein Organic Products and later to the St Helena Gold Mine, and five went directly to the St Helena Gold Mine. At St Helena they were, as best as could be ascertained, renumbered as shown in the table below:^[4]

Illustration

The main picture and those following offer views of the Class 16C locomotive before reboilering, with the original cab, and the Class 16CR after reboilering, with the Watson cab.

• 
  NBL builders's picture of Class 16C no. 823, c. 1921
• 
  Class 16C no. 823 before reboilering, c. 1930
• 
  Class 16CR no. 840 at De Aar, 1978
• 
  Class 16CR no. 813 as Durnacol no. 2, Dannhauser, 1979
• 
  Class 16CR no. 821 as St Helena Gold Mine no. 1, 1981

References

Wikimedia Commons has media related to South African Class 16C (4-6-2).

Locomotives of South Africa
Steam	7' ¼" gauge East London 0-4-0VB Table Bay 0-4-0ST Table Bay 0-4-0T Table Bay 0-4-0WT 4' 8½" gauge Cape 0-4-0T Blackie Cape 0-4-2 Cape 2-4-0T CGR 0-4-0ST Aid Natal 0-4-0ST Durban Natal 0-4-0WT Natal Natal 4-4-0T Perseverance 3' 6" gauge Tank engines CGR 0-4-0ST 1873 CGR 0-4-0ST 1874 CGR 0-4-0ST 1881 CGR 0-4-0ST 1881 Coffee Pot CGR 0-6-0ST CGR 0-6-0T CGR 2-6-0ST 1900 CGR 2-6-0ST 1902 CGR 1st Class 0-4-0ST 1875 CGR 1st Class 0-4-0ST 1876 CGR 1st Class 2-6-0ST CGR 1st Class 4-4-0T CGR 2nd Class 4-4-0T CGR 3rd Class 2-6-0T CGR Railmotor CSAR Class C CSAR Class E CSAR Rack 4-6-4RT CSAR Railmotor Durban's Congella Durban's Edward Innes Durban's John Milne Durban's Sir Albert Port Elizabeth 0-4-0ST Kowie Railway 0-6-0T Kowie Railway 4-4-0T Metropolitan & Suburban 4-6-2T NGR 2-6-0T Durban & Pietermaritzburg NGR Class I 2-6-2T NGR Class K 0-4-0ST NGR Class K 0-6-0ST NGR Class K 2-6-0T NZASM 10 Tonner NZASM 13 Tonner NZASM 14 Tonner NZASM 18 Tonner NZASM 19 Tonner NZASM 32 Tonner NZASM 40 Tonner PPR 26 Tonner PPR 35 Tonner Portuguese SAR Class A SAR Class B SAR Class C SAR Class C1 SAR Class C2 SAR Class D SAR Class E SAR Class F SAR Class G SAR Class H SAR Class H1 SAR Class H2 SAR Class J SAR Class K SAR Railmotor SAR Dock 0-4-0ST SAR Dock 0-4-0T SWA 2-8-0T 3' 6" gauge Tender engines CGR 1st Class 2-6-0 1876 BP CGR 1st Class 2-6-0 1876 Kitson CGR 1st Class 2-6-0 1879 CGR 1st Class 2-6-0 1891 CGR 1st Class 4-4-0 CGR 1st Class 4-4-0TT CGR 2nd Class 2-6-2TT CGR 3rd Class 4-4-0 1883 CGR 3rd Class 4-4-0 1884 CGR 3rd Class 4-4-0 1889 CGR 3rd Class 4-4-0 1898 CGR 3rd Class 4-4-0 1901 CGR 3rd Class 4-4-0 1903 CGR 4th Class 4-4-2 CGR 4th Class 4-6-0TT 1880 CGR 4th Class 4-6-0TT 1882 CGR 4th Class 4-6-0TT 1882 Joy CGR 4th Class 4-6-0TT 1884 CGR 5th Class 4-6-0 1890 CGR 5th Class 4-6-0 1891 NGR Havelock NGR Class I SAR Class Exp 1 SAR Class Exp 2 SAR Class Exp 3 SAR Class Exp 4 SAR Class Exp 5 SAR Class Exp 6 SAR Class S SAR Class S1 SAR Class S2 SAR Class 1 SAR Class 1A SAR Class 1B SAR Class 2 SAR Class 2C SAR Class 3 SAR Class 3A SAR Class 3B SAR Class 4 SAR Class 4A SAR Class 5 SAR Class 5A SAR Class 5B SAR Class 6 SAR Class 6A SAR Class 6B SAR Class 6C SAR Class 6D SAR Class 6E SAR Class 6F SAR Class 6G SAR Class 6H SAR Class 6J SAR Class 6K SAR Class 6L SAR Class 6Y SAR Class 6Z SAR Class 7 SAR Class 7A SAR Class 7B SAR Class 7C SAR Class 7D SAR Class 7E SAR Class 7F SAR Class 8 SAR Class 8A SAR Class 8B SAR Class 8C SAR Class 8D SAR Class 8E SAR Class 8F SAR Class 8R SAR Class 8X SAR Class 8Y SAR Class 8Z SAR Class 9 SAR Class 10 SAR Class 10A SAR Class 10B SAR Class 10C SAR Class 10D SAR Class 11 SAR Class 12 SAR Class 12A SAR Class 12B SAR Class 13 SAR Class 14 SAR Class 14A SAR Class 14B SAR Class 14C 1st SAR Class 14C 2nd SAR Class 14C 3rd SAR Class 14C 4th SAR Class 15 SAR Class 15A SAR Class 15B SAR Class 15C SAR Class 15CA SAR Class 15E SAR Class 15F SAR Class 16 SAR Class 16A SAR Class 16B SAR Class 16C SAR Class 16D SAR Class 16DA 1928 SAR Class 16DA 1930 SAR Class 16E SAR Class 17 SAR Class 18 SAR Class 19 SAR Class 19A SAR Class 19B SAR Class 19C SAR Class 19D SAR Class 20 SAR Class 21 SAR Class 23 SAR Class 24 SAR Class 25 SAR Class 25NC SAR Class 26 SAR Katanga SWA 2-8-0 3' 6" gauge Articulated engines CGR Fairlie CGR Kitson-Meyer SAR Class FC SAR Class FD SAR Class GA SAR Class GB SAR Class GC SAR Class GCA SAR Class GD SAR Class GDA SAR Class GE SAR Class GEA SAR Class GF SAR Class GG SAR Class GH SAR Class GK SAR Class GL SAR Class GM SAR Class GMA SAR Class GO SAR Class HF SAR Class KM SAR Class MA SAR Class MB SAR Class MC SAR Class MC1 SAR Class MD SAR Class ME SAR Class MF SAR Class MG SAR Class MH SAR Class MJ SAR Class MJ1 SAR Class U 2' 6" gauge Cape Copper John King & Miner Cape Copper Britannia Cape Copper Caledonia Cape Copper Clara Cape Copper Condenser Cape Copper Scotia Namaqua Copper Pioneer Walvis Bay 2-4-2T Hope 2' & 600mm gauges ACR Class NG-G16A CGR NG 0-4-0T CGR NG 0-6-0T CGR NG 4-6-2T CGR Type A 2-6-4T CGR Type C 0-4-0T NGR Class N 4-6-2T SAR Dutton SAR NG 0-4-0T SAR Class NG1 SAR Class NG2 SAR Class NG3 SAR Class NG4 SAR Class NG5 SAR Class NG6 SAR Class NG7 SAR Class NG8 SAR Class NG9 SAR Class NG10 SAR Class NG-G11 SAR Class NG-G12 SAR Class NG-G13 SAR Class NG-G14 SAR Class NG15 SAR Class NG-G16 SWA Class Ha SWA Class Hb SWA Class Hc SWA Class Hd SWA Jung SWA Zwillinge
Electric	Amcoal Class E38 SAR Class ES SAR Class ES1 SAR Class Exp-AC SAR Class 1E SAR Class 2E SAR Class 3E SAR Class 4E SAR Class 5E s1 SAR Class 5E s2 SAR Class 5E s3 SAR Class 5E1 s1 SAR Class 5E1 s2 SAR Class 5E1 s3 SAR Class 5E1 s4 SAR Class 5E1 s5 SAR Class 6E SAR Class 6E1 s1 SAR Class 6E1 s2 SAR Class 6E1 s3 SAR Class 6E1 s4 SAR Class 6E1 s5 SAR Class 6E1 s6 SAR Class 6E1 s7 SAR Class 6E1 s8 SAR Class 6E1 s9 SAR Class 6E1 s10 SAR Class 6E1 s11 SAR Class 7E SAR Class 7E1 SAR Class 7E2 s1 SAR Class 7E2 s2 SAR Class 7E3 s1 SAR Class 7E3 s2 Spoornet Class 7E4 SAR Class 8E SAR Class 9E s1 SAR Class 9E s2 SAR Class 10E SAR Class 10E1 s1 Spoornet Class 10E1 s2 SAR Class 10E2 SAR Class 11E SAR Class 12E Spoornet Class 14E Spoornet Class 14E1 TFR Class 15E Spoornet Class 16E Spoornet Class 17E Spoornet Class 18E s1 TFR Class 18E s2 TFR Class 19E TFR Class 20E TFR Class 21E TFR Class 22E
Gas-electric	SAR Gas-electric
Diesel	3' 6" gauge Diesel-electric PRASA Class Afro 4000 SAR Class DS SAR Class DS1 SAR Class 31-000 SAR Class 32-000 SAR Class 32-200 SAR Class 33-000 SAR Class 33-200 SAR Class 33-400 SAR Class 34-000 SAR Class 34-200 SAR Class 34-400 SAR Class 34-500 SAR Class 34-600 SAR Class 34-800 SAR Class 34-900 SAR Class 35-000 SAR Class 35-200 SAR Class 35-400 SAR Class 35-600 TFR Class 35-800 SAR Class 36-000 SAR Class 36-200 SAR Class 37-000 Spoornet Class 39-000 TFR Class 39-200 TFR Class 43-000 TFR Class 44-000 2' gauge Diesel-electric SAR Class 91-000 3' 6" gauge Diesel-hydraulic SAR Class 61-000 3' 6" gauge Electro-diesel Spoornet Class 38-000
List of South African locomotive classes South African locomotive numbering and classification

South African steam locomotive tenders
Cape gauge	Type CL Type CZ Type ET Type ET1 Type EW Type EW1 Type EW2 Type FT Type GT Type HT Type JT Type JT1 Type JV Type KT Type LP Type MP Type MP1 Type MR Type MS Type MT Type MT1 Type MT2 Type MX Type MY Type MY1 Type SH Type SK Type TJ Type TL Type TM Type WE Type WG Type X-17 Type X-20 Type XC Type XC1 Type XD Type XE Type XE1 Type XF Type XF1 Type XF2 Type XJ Type XM Type XM1 Type XM2 Type XM3 Type XM4 Type XP1 Type XS Type YB Type YC Type YE Type YE1 Type ZA Type ZB Type ZC Type ZE
List of South African locomotive classes South African locomotive history