South African type XP1 tender

South African type XP1 tender
Type XP1 tender on SAR Class 4AR no. 1560, c. 1961
Type and origin
LocomotiveSAR Classes MC1, 4AR & 10
DesignerSouth African Railways
(D.A. Hendrie)
BuilderNorth British Locomotive Company
In servicec. 1940
Specifications
Configuration2-axle bogies
Gauge3 ft 6 in (1,067 mm) Cape gauge
Length25 ft 10+34 in (7,893 mm)
Wheel dia.34 in (864 mm)
Wheelbase16 ft 9 in (5,105 mm)
 • Bogie4 ft 7 in (1,397 mm)
Axle load13 LT 15 cwt (13,970 kg)
 • Front bogie27 LT 10 cwt (27,940 kg)
 • Rear bogie23 LT 11 cwt (23,930 kg)
Weight empty49,452 lb (22,431 kg)
Weight w/o51 LT 1 cwt (51,870 kg)
Fuel typeCoal
Fuel cap.10 LT (10.2 t)
Water cap.4,250 imp gal (19,300 L)
StokingManual
CouplersDrawbar & AAR knuckle
Career
OperatorsSouth African Railways
NumbersSAR 1634

The South African type XP1 tender was a steam locomotive tender.

The Type XP1 tender first entered service in 1913 as a Type MP1, as tender to a Class MC1 Mallet locomotive. One of the Type MP1 tenders was later modified to suit a Class 10 locomotive and reclassified to Type XP1. It was subsequently attached to a Class 4AR locomotive.[1][2][3][4]

Origin

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The Type XP1 tender was built as a Type MP1 tender by North British Locomotive Company in 1913.[2][4]

Type MP1 tenders originally entered South African Railways (SAR) service in 1912, as tenders to Class 12 Mountain type locomotives. The locomotive and tender were designed by D.A. Hendrie, Chief Mechanical Engineer of the SAR. Tenders were numbered for their original engines and an oval number plate, bearing the engine number and often also the tender type, was attached to the rear end of the tender. The particular tender which was to be modified to Type XP1, entered service in 1913 as tender to Class MC1 Mallet no. 1634.[2][3][4]

Rebuilding

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At some stage, probably after the Class MC1 were withdrawn from service in 1939, the intermediate draw and buffing gear of Type MP1 tender no. 1634 was altered to suit Class 10 4-6-2 Pacific no. 746. This modification converted no. 1634 to the sole Type XP1 tender. During the early 1960s, the tender was attached to Class 4AR Mountain no. 1560. This locomotive and the tender were both withdrawn from service by 1974.[4]

Characteristics

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The Type XP1 tender had a water capacity of 4,250 imperial gallons (19,300 litres), a coal capacity of 10 long tons (10.2 tonnes) and a maximum axle load of 13 long tons 15 hundredweight (13,970 kilograms). Type XP1 tender no. 1634 is known to have served as tender to three locomotives of different classes.[3][4]

Classification letters

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Since many tender types are interchangeable between different locomotive classes and types, a tender classification system was adopted by the SAR. The first letter of the tender type indicates the classes of engines to which it could be coupled. The "X_" tenders could be used with the locomotive classes as shown.[4]

The second letter indicates the tender's water capacity. The "_P" tenders had a capacity of 4,250 imperial gallons (19,300 litres; 5,100 US gallons).[4]

A number, when added after the letter code, indicates differences between similar tender types, such as function, wheelbase or coal bunker capacity. Since no Type XP tender exists, the digit was not necessary in respect of the Type XP1 tender and seems to have been carried over from its previous Type MP1 classification.[4]

Modifications

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Prior to the modification of its intermediate draw and buffing gear to convert it to the Type XP1, the tender had already been modified. Most of the Type MP1 tenders were modified by shortening and raising the sides of the coal bunker, in effect making the coal at the rear of the bunker more easily accessible to the stoker and apparently without affecting the tender's coal capacity. The profile of the Type XP1 tender corresponds with the official dimensional drawing of such a modified Type MP1.[4]

Illustration

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References

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  1. ^ Holland, D.F. (1971). Steam Locomotives of the South African Railways. Vol. 1: 1859–1910 (1st ed.). Newton Abbott, England: David & Charles. pp. 129–130. ISBN 978-0-7153-5382-0.
  2. ^ a b c Holland, D. F. (1972). Steam Locomotives of the South African Railways. Vol. 2: 1910-1955 (1st ed.). Newton Abbott, England: David & Charles. pp. 12–13, 20–23. ISBN 978-0-7153-5427-8.
  3. ^ a b c South African Railways & Harbours/Suid Afrikaanse Spoorweë en Hawens (15 Aug 1941). Locomotive Diagram Book/Lokomotiefdiagramboek, 3'6" Gauge/Spoorwydte. SAR/SAS Mechanical Department/Werktuigkundige Dept. Drawing Office/Tekenkantoor, Pretoria. p. 44.
  4. ^ a b c d e f g h i South African Railways & Harbours/Suid Afrikaanse Spoorweë en Hawens (15 Aug 1941). Locomotive Diagram Book/Lokomotiefdiagramboek, 2'0" & 3'6" Gauge/Spoorwydte, Steam Locomotives/Stoomlokomotiewe. SAR/SAS Mechanical Department/Werktuigkundige Dept. Drawing Office/Tekenkantoor, Pretoria. pp. 6a-7a, 45.