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

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South African Class NG G16 2-6-2+2-6-2
SAR Class NG G16 113 (2-6-2+2-6-2).JPG
No. NG113 at Sandstone Estates, 9 April 2006
Type and origin
♠ All except no. NG137-NG143
All except no. NG137-NG143 & NG149-NG156
No. NG137-NG143 - No. NG149-NG156
Power type Steam
Designer Hannoversche Maschinenbau AG
South African Railways
Builder Société Anonyme John Cockerill
Beyer, Peacock and Company
Hunslet-Taylor
Serial number Cockerill 3265-3268
Beyer, Peacock 6919-6926, 7426-7432, 7862-7868
Hunslet-Taylor 3894-3901
Model Class NG G16
Build date 1937-1968
Total produced 34
Rebuilder Alfred County Railway
Rebuild date 1989-1990
Number rebuilt 2 to Class NG G16A
Specifications
Configuration 2-6-2+2-6-2 (Double Prairie)
Driver 3rd & 4th coupled axles
Gauge 2 ft (610 mm) narrow
Leading dia. 21 in (533 mm)
Coupled dia. 33 in (838 mm)
Trailing dia. 21 in (533 mm)
Minimum curve 160 ft (49 m)
Wheelbase 43 ft 3 in (13,183 mm)
 • Engine 13 ft 10 12 in (4,229 mm) each
 • Coupled 6 ft 3 in (1,905 mm) each
Pivot centres 23 ft 9 in (7,239 mm)
Length:
 • Over couplers 48 ft 5 14 in (14,764 mm)
Width 7 ft (2,134 mm)
Height 10 ft 4 in (3,150 mm)
Frame type Bar
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 type Coal
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 type Round-top
 • Firegrate area 19.5 sq ft (1.81 m2)
Boiler:
 • Pitch 5 ft 5 in (1,651 mm)
 • Diameter 4 ft 7 34 in (1,416 mm)
 • Tube plates 9 ft 3 58 in (2,835 mm)
 • Small tubes 152: 1 34 in (44 mm)
 • Large tubes 15: 5 12 in (140 mm)
Boiler pressure 180 psi (1,241 kPa)
Safety valve Pop
Heating surface 921.1 sq ft (85.57 m2)
 • Tubes 839 sq ft (77.9 m2)
 • Firebox 82.1 sq ft (7.63 m2)
Superheater:
 • Heating area 149 sq ft (13.8 m2)
Cylinders Four
Cylinder size 12 in (305 mm) bore
16 in (406 mm) stroke
Valve gear Walschaerts
Valve type Piston
Couplers Bell-and-hook (Cape)
Johnston link-and-pin (Natal)
Performance figures
Tractive effort 18,850 lbf (83.8 kN) @ 75%
Career
Operators South African Railways
Alfred County Railway
Welsh Highland Railway
Class Class NG G16
Number in class 34
Numbers NG85-NG88, NG109-NG116, NG125-NG131, NG137-NG143, NG149-NG156
Delivered 1937-1968
First run 1937

The South African Railways Class NG G16 2-6-2+2-6-2 of 1937 was a narrow gauge steam locomotive.

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

Manufacturers[edit]

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[edit]

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 large radius curved tops on the water tanks.[1]

Beyer, Peacock[edit]

SAR Class NG G16 113 (2-6-2+2-6-2) ID.JPG

The second order of eight locomotives was delivered from Beyer, Peacock and Company 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. These and the subsequent locomotives had welded water and coal bunkers and flat-topped water tanks with rounded top side edges.[1][2][3]

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. 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][6]

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][6]

Hunslet-Taylor[edit]

Class NG G16 152 (2-6-2+2-6-2) ID.JPG
SAR Class NG G16 153 (2-6-2+2-6-2) ID.JPG

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]

Service[edit]

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][6]

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[edit]

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.[7][8]

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.[7][8][9]

Preservation[edit]

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. By 2012, at least three establishments still operated or were restoring ex-SAR Class NG G16 Garratts.[9]

Welsh Highland Railway[edit]

The Welsh Highland Railway in the United Kingdom owns four Class NG G16 locomotives. One, no. NG140, is undergoing restoration to operating condition while three locomotives, Cockerill-built no. NG87 and Beyer, Peacock-built numbers NG138 and NG143, are kept in excellent condition by this establishment which exhibits great pride in its heritage.[9] In addition, two other Class NG G16s, numbers NG109 and NG130, are based on the line but not owned by the railway. No. NG130 is undergoing a fast track restoration sponsored by its private owner with a ten-year operating agreement with the WHR in place from 2017. No. NG109 is stored as a kit of parts.

Sandstone Estates[edit]

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 kept in pristine condition 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.[9]

Puffing Billy Railway[edit]

The Puffing Billy Railway, located in the Dandenong Ranges east of Melbourne, Australia, began restoring Class NG G16 no. NG129 and regauging it to 2 ft 6 in (762 mm) as a backup for their Victorian Railways G class Garratt no. G42 at a time of increasing passenger loadings. Completion of no. NG129's restoration is planned to coincide with the next time that no. G42 is to be withdrawn for major maintenance. Faced with the need to manufacture a number of missing parts for no. NG129, the Puffing Billy has also purchased no. NG127 and a container of spare parts from a private owner in South Africa. This gives them many of the much needed missing parts and a second almost-complete Class NG G16 which will also be totally rebuilt in the future.[10]

Distribution[edit]

The last known fate of all the Class NG G16 locomotives, as of April 2017, are shown in Table I.[9]

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

Works numbers[edit]

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

Illustration[edit]

The main picture and the following photographs offer views of the various models of the Class NG G16 locomotive.

References[edit]

  1. ^ a b c d e f g h i Durrant, A E (1989). Twilight of South African Steam (1st ed.). Newton Abbott, London: David & Charles. pp. 126–127. ISBN 0715386387. 
  2. ^ a b c d e f g h i j k l m n 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. ^ a b c d e Hamilton, Gavin N., The Garratt Locomotive - Garratt Locomotives produced by Beyer, Peacock, retrieved 10 November 2012 
  4. ^ a b c d 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. ^ a b c Soul of A Railway, System 3: Cape Midland, based in Port Elizabeth, Part 4: Loerie to Assegaaibos. Caption 4. (Accessed on 13 December 2016)
  7. ^ a b "The Ultimate Steam Page – P. Girdlestone". trainweb.org. Retrieved 2009-07-10. 
  8. ^ a b c "Alfred County Railway 2-6-2+2-6-2 NG G16A Garratts 141 & 155". martynbane.co.uk. Retrieved 2009-07-10. 
  9. ^ a b c d e 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. 
  10. ^ a b "Puffing Billy Monthly News, February 2012". Bill Russell. Retrieved 2012-01-30. 
  11. ^ a b c d e f g h i j 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.
  12. ^ Welsh Highland Railway news
  13. ^ a b Stars of Sandstone, Official Operating Programme for 12th - 21st April 2014 (stars 2014 - official operating programme-7.pdf)
  14. ^ Exmoor Steam Railway and its history