South African type XM4 tender explained

South African type XM4 tender
Locomotive:	SAR Class MF
Designer:	American Locomotive Company
Builder:	American Locomotive Company
Date:	1911
Wheelarr:	2-axle bogies
Bogies:	Diamond frame
Wheeldiameter:	300NaN0
Wheelbase:	17feet
Bogie:	5feet
Axleload:	12lt average
Bogieload:	25lt average
Tenderempty:	51840lb
Tenderworking:	51sigfig=4NaNsigfig=4
Fueltype:	Coal
Fuelcap:	101NaN1
Watercap:	4000sigfig=3NaNsigfig=3
Stoking:	Manual
Coupling:	Drawbar & Johnston link-and-pin Drawbar & AAR knuckle (1930s)
Operator:	South African Railways
Fleetnumbers:	SAR 1629-1633

See main article: article and South African steam locomotive tenders.

The South African type XM4 tender was a steam locomotive tender.

Type XM4 tenders entered service in November 1911, as tenders to the second batch of Superheated Mallet type steam locomotives which were delivered to the Central South African Railways in that year. These locomotives were designated Class MF on the South African Railways in 1912.^{[1] [2]}

Manufacturer

Type XM4 tenders were built in 1911 by the American Locomotive Company (ALCO).^{[1] [2]}

In November 1911, the Central South African Railways (CSAR) placed a second batch of five Mallet articulated compound steam locomotives in service, built by ALCO. These locomotives were designated Class MF on the South African Railways (SAR) in 1912. The Type XM4 tender entered service as tenders to these five engines.^{[1] [2]}

Characteristics

As built, the tender had a coal capacity of 101NaN1 and a water capacity of 4000sigfig=3NaNsigfig=3, with an average maximum axle load of 12lt. It rode on diamond frame bogies with a 5feet wheelbase per bogie.^{[1] [2]}

Locomotive

In the SAR years, tenders were numbered for the engines they were delivered with. In most cases, an oval number plate, bearing the engine number and often also the tender type, would be attached to the rear end of the tender.^{[2] [3]}

Only the second batch of five Class MF locomotives were delivered new with Type XM4 tenders. They were numbered in the range from 1629 to 1633, directly onto the SAR roster, marking the introduction of the SAR renumbering scheme under the Union programme.^{[1] [2] [3] [4]}

Classification letters

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 can be coupled. The "X_" tenders could be used with the locomotive classes as shown.^[2]

• Cape Government Railways Mountain, SAR Class 4.
• SAR Class 4A.
• SAR Class 5.
• Cape Government Railways 6th Class of 1897, SAR Class 6B.
• Oranje-Vrijstaat Gouwerment-Spoorwegen 6th Class L3, SAR Class 6E.
• Cape Government Railways 6th Class of 1901 (Neilson, Reid), SAR Class 6H.
• Cape Government Railways 6th Class of 1902, SAR Class 6J.
• Cape Government Railways 8th Class of 1902, SAR Class 8.
• Imperial Military Railways 8th Class, SAR Class 8A.
• CSAR Class 8-L2, SAR Class 8B.
• CSAR Class 8-L3, SAR Class 8C.
• Cape Government Railways 8th Class 4-8-0 of 1903, SAR Class 8D.
• Cape Government Railways 8th Class Experimental, SAR Class 8E.
• Cape Government Railways 8th Class 4-8-0 of 1904, SAR Class 8F.
• Cape Government Railways 8th Class 2-8-0 of 1903, SAR Class 8Y.
• Cape Government Railways 8th Class 2-8-0 of 1904, SAR Class 8Z.
• CSAR Class 9, SAR Class 9.
• CSAR Class 10, SAR Class 10.
• CSAR Class 10-2 Saturated, SAR Class 10A.
• CSAR Class 10-2 Superheated. SAR Class 10B.
• CSAR Class 10-C, SAR Class 10C.
• CSAR Class 11, SAR Class 11.
• Cape Government Railways 9th Class of 1903, SAR Class Experimental 4.
• Cape Government Railways 9th Class of 1906, SAR Class Experimental 5.
• Cape Government Railways 10th Class, SAR Class Experimental 6.
• SAR Class ME.
• CSAR Mallet Superheated, SAR Class MF.

The second letter indicates the tender's water capacity. The "_M" tenders had a capacity of 4000impgal.^[2]

A number, when added after the letter code, usually indicates differences between similar tender types, such as function, wheelbase or coal bunker capacity.^[2]

Notes and References

1. 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. 43.
2. 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, 43.
3. Classification of S.A.R. Engines with Renumbering Lists, issued by the Chief Mechanical Engineer's Office, Pretoria, January 1912 (Reprinted in April 1987 by SATS Museum, R.3125-6/9/11-1000)
4. Espitalier, T.J.; Day, W.A.J. (1945). The Locomotive in South Africa - A Brief History of Railway Development. Chapter VII - South African Railways (Continued). South African Railways and Harbours Magazine, May 1945. p. 347.