South African Class NG G16 2-6-2+2-6-2

The South African Railways Class NG G16 2-6-2+2-6-2 is a narrow gauge steam locomotive class.

South African Class NG G16 2-6-2+2-6-2
No. NG113 at Sandstone Estates in April 2006
Type and origin
♠ All except no. NG137-NG143
♥ All except no. NG137-NG143 & NG149-NG156
♣ No. NG137-NG143 – ♦ No. NG149-NG156
Power typeSteam
DesignerHannoversche Maschinenbau AG
South African Railways
BuilderSociété Anonyme John Cockerill
Beyer, Peacock & Company
Hunslet-Taylor
Serial numberCockerill 3265-3268
Beyer, Peacock 6919-6926, 7426-7432, 7862-7868
Hunslet-Taylor 3894-3901
ModelClass NG G16
Build date1937-1968
Total produced34
RebuilderAlfred County Railway
Rebuild date1989-1990
Number rebuilt2 to Class NG G16A
Specifications
Configuration:
​
 • Whyte2-6-2+2-6-2
 • UIC1'C1'+1'C1'h4t
Driver3rd & 4th coupled axles
Gauge2 ft (610 mm) narrow
Leading dia.21 in (533 mm)
Coupled dia.33 in (838 mm)
Trailing dia.21 in (533 mm)
Minimum curve160 ft (49 m)
Wheelbase43 ft 3 in (13,183 mm)
 • Engine13 ft 10+1⁄2 in (4,229 mm) each
 • Coupled6 ft 3 in (1,905 mm) each
Pivot centres23 ft 9 in (7,239 mm)
Length:
​
 • Over couplers48 ft 5+1⁄4 in (14,764 mm)
Width7 ft (2,134 mm)
Height10 ft 4 in (3,150 mm)
Frame typeBar
Axle load♠ 6 LT 18 cwt (7,011 kg)
♣ 6 LT 17 cwt 3 qtr (6,998 kg)
 • Leading♠ 6 LT 10 cwt (6,604 kg) front
5 LT 14 cwt (5,791 kg) rear
♣ 6 LT 7 cwt 2 qtr (6,477 kg) front
6 LT 7 cwt 1 qtr (6,465 kg) rear
 • 1st coupled♠ 6 LT 18 cwt (7,011 kg)
♣ 6 LT 14 cwt 3 qtr (6,846 kg)
 • 2nd coupled♠ 6 LT 6 cwt (6,401 kg)
♣ 6 LT 17 cwt 3 qtr (6,998 kg)
 • 3rd coupled♠ 6 LT 4 cwt (6,299 kg)
♣ 6 LT 15 cwt (6,858 kg)
 • 4th coupled♠ 6 LT 15 cwt (6,858 kg)
♣ 6 LT 14 cwt 2 qtr (6,833 kg)
 • 5th coupled♠ 6 LT 17 cwt (6,960 kg)
♣ 6 LT 14 cwt (6,808 kg)
 • 6th coupled♠ 6 LT 1 cwt (6,147 kg)
♣ 6 LT 14 cwt 3 qtr (6,846 kg)
 • Trailing♠ 3 LT 14 cwt (3,759 kg) front
3 LT 19 cwt (4,013 kg) rear
♣ 4 LT 1 cwt 1 qtr (4,128 kg) front
3 LT 10 cwt (3,556 kg) rear
Adhesive weight♠ 39 LT 1 cwt (39,680 kg)
♣ 40 LT 10 cwt 3 qtr (41,190 kg)
Loco weight♠ 59 LT 2 cwt (60,050 kg)
♣ 61 LT 5 cwt 2 qtr (62,260 kg)
Fuel typeCoal
Fuel capacity♠ 4 LT (4.1 t)
♣ 6 LT 4 cwt (6.3 t)
Water cap.♥ 1,285 imp gal (5,840 L) front
540 imp gal (2,450 L) rear
♣ 1,325 imp gal (6,020 L) front
♦ 1,325 imp gal (6,020 L) front
540 imp gal (2,450 L) rear
Firebox typeRound-top
 • Firegrate area19.5 sq ft (1.81 m2)
Boiler:
​
 • Pitch5 ft 5 in (1,651 mm)
 • Diameter4 ft 7+3⁄4 in (1,416 mm)
 • Tube plates9 ft 3+5⁄8 in (2,835 mm)
 • Small tubes152: 1+3⁄4 in (44 mm)
 • Large tubes15: 5+1⁄2 in (140 mm)
Boiler pressure180 psi (1,241 kPa)
Safety valvePop
Heating surface921.1 sq ft (85.57 m2)
 • Tubes839 sq ft (77.9 m2)
 • Firebox82.1 sq ft (7.63 m2)
Superheater:
​
 • Heating area149 sq ft (13.8 m2)
Cylinders4
Cylinder size12 in (305 mm) bore
16 in (406 mm) stroke
Valve gearWalschaerts
Valve typePiston
CouplersBell-and-hook (Cape)
Johnston link-and-pin (Natal)
Performance figures
Tractive effort18,850 lbf (83.8 kN) @ 75%
Career
OperatorsSouth African Railways
Alfred County Railway
Welsh Highland Railway
ClassClass NG G16
Number in class34
NumbersNG85-NG88, NG109-NG116, NG125-NG131, NG137-NG143, NG149-NG156
Delivered1937-1968
First run1937

Between 1937 and 1968, the South African Railways placed 34 Class NG G16 Garratt articulated 2-6-2+2-6-2 steam locomotives in service on the Avontuur Railway and on the Natal narrow gauge lines.[1][2]

Manufacturers
Cockerill-built no. NG86, still inscribed NG/G13, c. 1937
Beyer, Peacock-built no. NG115, c. 1939
Beyer, Peacock-built no. NG128, c. 1951
Beyer, Peacock-built no. TC11 for Tsumeb Copper, possibly SAR no. NG142, c 1958
Hunslet-Taylor-built, possibly no. NG149, c. 1967

The success of the Class NG G13 narrow gauge Garratts that were introduced by the South African Railways (SAR) in 1927 led to a decision that any additional narrow gauge articulated locomotives would be of the same design. Altogether 34 more 2-6-2+2-6-2 Double Prairie type narrow gauge locomotives were built, spread over five orders from three manufacturers over a span of 32 years.[2][3][4][5]

Cockerill

In 1937, Société Anonyme John Cockerill of Seraing in Belgium delivered four new 2-6-2+2-6-2 locomotives, numbered in the range from NG85 to NG88, which were so similar to the older locomotives that they were initially designated Class NG G13 as well. However, in view of the fact that all the carrying wheels were fitted with roller bearing axle boxes and arranged as swiveling pony trucks, compared to the Class NG G13 of which the inner carrying wheels were built to the Gölsdorf system which allowed the axle some lateral movement, it was soon decided to reclassify them to Class NG G16.[2][4]

These pre-war locomotives, like the earlier Class NG G13 locomotives, were built with riveted coal and water bunkers and with elliptical tops on the water tanks.[1]

Beyer, Peacock

The second order of eight locomotives was delivered from Beyer, Peacock & Company, England in 1939. They were numbered in the range from NG109 to NG116.[1][2][3]

The third order was for a further seven locomotives in 1951, numbered in the range from NG125 to NG131, once again from Beyer, Peacock. They still had elliptical tops on the water tanks and both tank and bunker were riveted as per the pre-war machines, however on the boiler the location of the safety valves, clack valves and main manifold (amongst other details) changed to what would become the standard for all remaining builds.[1][2][3][6]

The fourth batch of seven locomotives, numbered in the range from NG137 to NG143, were the last steam locomotives to be built by Beyer, Peacock and were built to the specifications of the Tsumeb Copper Corporation in South West Africa (SWA). They were mechanically similar to the earlier and subsequent Class NG G16 locomotives, but with a revised coal and water carrying arrangement. These locomotives had an enlarged front water tank capacity, but carried no water in their rear bunkers which consequently had a larger coal capacity. They had flat-topped water tanks with rounded top side edges, and were the first NGG16s to have welded tanks. It was planned to use them as tank-and-tender Garratts, semi-permanently attached to a water tender for use across the Namib desert in SWA, as was the practice with the Cape gauge Classes GM, GMA and GO tank-and-tender Garratts in South Africa.[2][3][7]

However, while the locomotives were being built, the decision was made to convert all the SWA narrow gauge lines to Cape gauge. In terms of a prior agreement between the SAR and the Tsumeb Copper Corporation, the SAR would purchase any narrow gauge locomotives that would become redundant should the re-gauging of the SWA system take place. The new locomotives were therefore delivered directly to the SAR in 1958.[2]

On the Avontuur Railway, these locomotives were used as tank-and-tender Garratts, but when the Langkloof members of the class were transferred to Natal in 1964, the water tenders were dispensed with since watering points were much closer together in Natal as a consequence of the early use of tank engines on those narrow-gauge branches.[2][7]

Hunslet-Taylor

The final order for eight locomotives in 1967, numbered in the range from NG149 to NG156, turned out to be the last new steam locomotives to be ordered by the SAR. Beyer-Peacock had stopped building steam locomotives after the last batch of Class NG G16 in 1958 and by 1968 they were in the process of closing the business altogether. Since no other overseas manufacturers were available to supply them, they were built by Hunslet-Taylor in Germiston using boilers supplied by their overseas principals, the Hunslet Engine Company in England. Built in 1967 and 1968, these locomotives had the same enlarged capacity front water tanks as those of the Tsumeb group, but their rear bunkers were identical to those of the 1951 batch of locomotives and carried both coal and water.[2][4]

Cabside number plates

After the Official Languages of the Union Act No 8 of 1925 was passed on 8 May 1925, bilingual English and Afrikaans cabside number plates began to appear on SAR locomotives, initially inscribed "SOUTH AFRICAN RAILWAYS" at the top and "SUID AFRIKANSE SPOORWEË" at the bottom. The Afrikaans spelling conventions were changed from time to time in the early years. On postage stamps, for example, it was "Zuid Afrika" from 1913, "Suidafrika" from the airmail stamps of 1925 and hyphenated "Suid-Afrika" from 1933. On cabside number plates, the spelling of the Afrikaans inscription was later altered with "AFRIKANSE" changed to "AFRIKAANSE" and with "SUID AFRIKAANSE SPOORWEË" unhyphenated, and stil later to "SUID-AFRIKAANSE SPOORWEË" hyphenated.[8]

The Cockerill-built locomotives were delivered with bilingual cabside number plates inscribed "NG/G13" and with the older style Afrikaans "SUID AFRIKANSE SPOORWEË" at the bottom. When they were designated Class NG G16, the "NG/G13" was altered to "NG/G16" by milling out the 3 and riveting on a 6, as shown.[2]

Service

The Cockerill locomotives, numbers NG85 to NG88, remained in Natal for most of their service lives.[1][2]

The Beyer, Peacock locomotives ordered by the SAR, numbers NG109 to NG116 and NG125 to NG131, were shared more or less equally between the Natal and Langkloof lines.[1][2]

The seven Beyer, Peacock locomotives ordered by the Tsumeb Copper Corporation, numbers NG137 to NG143, were initially distributed between the Umzinto, Port Shepstone and Avontuur lines, but in 1964 the three that went to the Langkloof were also transferred to Natal.[1][2][7]

The Hunslet-Taylor locomotives, numbers NG149 to NG156, were placed in service on the Harding and Donnybrook branches in Natal in 1968.[1][2]

When the lower section of the Avontuur line was dieselised upon the arrival of the Class 91-000 diesel-electric locomotives in 1973, all the Class NG G16 locomotives still in service were transferred to various branches in Natal, where they remained until they were withdrawn from service.[2]

Class NG G16A

When the four Natal narrow gauge systems were closed down by the SAR, the Weenen and Mid-Illovo lines were lifted, but the Harding line was privatised as the Alfred County Railway (ACR), operating out of Port Shepstone.[1]

As part of their strategy to keep the railway competitive, two of the ACR's Class NG G16 locomotives were rebuilt using technology similar to that used in the Cape gauge Class 26 Red Devil. The rebuilding incorporated a gas producing combustion system (GPCS), Lempor exhausts, an improved spark arrester, lightweight multi-ring articulated piston valves, improved valve events and improved mechanical lubrication. The two locomotives which received this treatment, no. NG141 in 1989 and no. NG155 in 1990, were reclassified to Class NG G16A.[9][10]

In comparative testing, no. NG141 achieved a fuel saving of 25% compared to a standard Class NG G16 Garratt, a performance which was easily maintained in regular service. The cost of the work paid off financially within twelve months and led to a proposal to develop a Class NG G17, but that never materialised since the line's farming produce traffic was gradually lost to road transport on the improving road network.[9][10][11]

Preservation

Since withdrawal from SAR service, some locomotives were sold to foreign railways and into private hands and restored to operational condition, while others ended up in various degrees of preservation ranging across the spectrum from running order to staging to total abandonment. In 2017, at least four establishments still operated or were restoring ex-SAR Class NG G16 Garratts.[11] Several however, have now been cut up for scrap (see table below).

Welsh Highland Railway

The Welsh Highland Railway in Wales has five Class NG G16 locomotives. One, no. NG140, is used as a source of spare parts while four locomotives, Cockerill-built no. NG87 and Beyer, Peacock-built numbers NG130, NG138 and NG143, are used for operational purposes.

Sandstone Estates

The Sandstone Estates near Ficksburg in the Free State is home to a large number of Class NG G16 locomotives, either as the owners or as the custodian for locomotives belonging to individuals or other establishments. Three of their Class NG G16 locomotives are homed here, and are regularly run during the Estate's annual events like the Cosmos Festival, Cherry Festival, Stars of Sandstone and others. These are Cockerill-built no. NG88, Beyer, Peacock-built no. NG113 and Hunslet-Taylor-built no. NG153.[11]

Puffing Billy Railway

The Puffing Billy Railway, located in the Dandenong Ranges east of Melbourne, Australia, purchased NG129 in August 1996 from ACR shareholder Peter Newton. From 2008 they have completely rebuilt it, including re-gauging it to 2 ft 6 in (762 mm) as additional capacity at a time of increasing passenger loadings.[12] Completion of no. NG129's restoration was planned to coincide with the next time that no. G42 was to be withdrawn for major maintenance. The Puffing Billy Railway also purchased no. NG127 from Peter Newton in November 2011.[13] This gave them a second almost-complete Class NG G16 which will possibly also be totally rebuilt in the future. After first being steamed in September 2019 129, in November 2019 it underwent light engine and load testing.[14][15]

Distribution

The last known fate of all the Class NG G16 locomotives, as of October 25th 2022, are shown in Table I.

Table I
South African Class NG G16 2-6-2+2-6-2 locations

Works numbers

Their engine numbers, builders, years built and works numbers are listed in Table II.[3][4]

References
  1. Durrant, AE (1989). Twilight of South African Steam (1st ed.). Newton Abbott: David & Charles. pp. 126–127. ISBN 0715386387.
  2. Paxton, Leith; Bourne, David (1985). Locomotives of the South African Railways (1st ed.). Cape Town: Struik. pp. 10–11, 107, 109–110. ISBN 0869772112.
  3. Hamilton, Gavin N., The Garratt Locomotive - Garratt Locomotives produced by Beyer, Peacock, retrieved 10 November 2012
  4. Hamilton, Gavin N., The Garratt Locomotive - Garratt Locomotives from Other Builders, retrieved 10 November 2012
  5. South African Railways and Harbours Locomotive Diagram Book, 2'0" & 3'6" Gauge Steam Locomotives, 15 August 1941, as amended
  6. Payling, D (2012). Garratts & Kalaharis of the West Highland Railway (1st ed.). Porthmadog, Wales: The Ffestiniog & Welsh Highland Railways. pp. 129–130. ISBN 978 0 901848 10 9.
  7. Soul of A Railway, System 3: Cape Midland, based in Port Elizabeth, Part 4: Loerie to Assegaaibos. Caption 4. (Accessed on 13 December 2016)
  8. Hefferman, Lutz (1997). The South African Stamp Colour Catalogue (21st ed.). Lutz Hefferman, Johannesburg, 2000, pp. 37, 39, 45.
  9. "The Ultimate Steam Page – P. Girdlestone". trainweb.org. Retrieved 10 July 2009.
  10. "Alfred County Railway 2-6-2+2-6-2 NG G16A Garratts 141 & 155". martynbane.co.uk. Retrieved 10 July 2009.
  11. Middleton, John N. (2002). Railways of Southern Africa Locomotive Guide - 2002 (as amended by Combined Amendment List 4, January 2009) (2nd, Dec 2002 ed.). Herts, England: Beyer-Garratt Publications. pp. 32–33.
  12. Here & There Australian Railway Historical Society Bulletin issue 711 January 1997 page 30
  13. Puffing Billy Railway Light Railways issue 224 April 2012 page 35
  14. Another articulated NGG16 Garratt steams Heritage Railway issue 260 25 October 2019 page 23
  15. Rebuilt Garratt undertakes its first Australian run Track & Signal issue 23/4 November 2019 page 86
  16. Welsh Highland Railway news Welsh Highland Railway
  17. Equipment & Trains Exmoor Steam Railway
  18. SATS / Transnet NG/G16 Garratt Fleet Disposal Locomotives International issue 126 August 2020 page 4-13
  19. Stars of Sandstone, Official Operating Programme for 12th - 21st April 2014 (stars 2014 - official operating programme-7.pdf)

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