Bone-Guelma 4-6-2 Locomotives in Tunisia


Class Details by Steve Llanso of Sweat House Media

Class 189 (Locobase 15153)

Data from SACM diagrams UG Type 178, 184 from Elsassische Maschinenbau AG from locomotive book supplied by Dany Machi up at [] as

Diagrammes des machines SACM construites a GRAFENSTADEN (October 2007). Works numbers were 7568-7571.

Water-side diameters were 50 mm for the tubes, 133 mm for the flues, which yielded an evaporative heating surface area of 1,626 sq ft (151 sq m).

The Wikipedia summary of 4-6-2 locomotives ([], last accessed 25 April 2013) tells us that there were twelve in the class beginning with

181 - 185 (CFT 231.181 - 231.185) produced as works numbers 6599-6603 in 1914. Nine years later the CFT returned to SACM for three more (works numbers 7374-7376, road numbers 231.186-188. The data refer to the last four (189-192 in 1928). The other eight were quite similar.

They hauled main-line express passenger trains between Tunis and the Algerian border town of Ghardiamou about 211 km (131 miles) away. Heading south out of Tunis, other trains pulled by this class made several stops on their way to Bizerta, 98 km (62 miles) off.

This service continued until 1951, when the Tunis line started using diesels. Secondary line service by these locomotives ended in 1954-1955.


Class 801 - 1914 (Locobase 15154)

Data from SACM diagram Elsassische Maschinenbau AG from locomotive book supplied by Dany Machi up at [] as

Diagrammes des machines SACM construites a GRAFENSTADEN (October 2007). See also supplemented by "Recent Locomotives for the Bone-Guelma Railway", Locomotive Magazine, Volume XX [20] (15 October1914), p. 226-227. Works numbers were 6584-6588.

Water-side diameters were 50 mm for the tubes, 132 mm for the flues, which yielded an evaporative heating surface area of 1,614 sq ft (149.95 sq m).

These engines were the first Pacifics to operate in North Africa. They hauled trains over the 149 km (90.5 mile) between Tunis and Sousse and on to Sfax, 279 km (173.3 miles). The Wikipedia summary of 4-6-2 locomotives ([], last accessed 25 April 2013) claims that the class was a great success. During the 20 years between the two World Wars, the octet provided "the fastest metre gauge service in the world". They regularly reached speeds of 100 km/h (62.1 mph) spinning drivers of unusually large diameter that achieved an aspect ratio (diameter: track gauge) equivalent to wheels of more than seven feet on the standard gauge.

In 1928, the Tunisian State Railways bought three more of this class. The trios' boilers had fewer small tubes and more flues; see Locobase 15154.

After they were withdrawn in 1955-1958 in the face of Tunisian Railways' adoption of diesel power, five were sold to the Ferrocarril La Robla in Spain, where they operated into the late 1960s as 181-185.

Principal Dimensions by Steve Llanso of Sweat House Media

Class189801 - 1914
Locobase ID15153 15154
RailroadBone-GuelmaBone-Guelma
CountryTunisiaTunisia
Whyte4-6-24-6-2
Number in Class45
Road Numbers189-192801-805
GaugeStdMetre
Number Built45
BuilderSACMSACM
Year19421914
Valve GearWalschaertHeusinger
Locomotive Length and Weight
Driver Wheelbase (ft / m)12.47 / 3.8010.50 / 3.20
Engine Wheelbase (ft / m)30.51 / 9.3027.89 / 8.50
Ratio of driving wheelbase to overall engine wheelbase 0.41 0.38
Overall Wheelbase (engine & tender) (ft / m)48.56 / 14.80
Axle Loading (Maximum Weight per Axle) (lbs / kg)33,290 / 15,10026,455 / 12,000
Weight on Drivers (lbs / kg)99,869 / 45,30079,366 / 36,000
Engine Weight (lbs / kg)169,205 / 76,750125,663 / 57,000
Tender Loaded Weight (lbs / kg)81,350 / 36,900
Total Engine and Tender Weight (lbs / kg)250,555 / 113,650
Tender Water Capacity (gals / ML)4224 / 16
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 5.50 / 5
Minimum weight of rail (calculated) (lb/yd / kg/m)55 / 27.5044 / 22
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)68.90 / 175059.10 / 1500
Boiler Pressure (psi / kPa)171.10 / 11.80171.10 / 11.80
High Pressure Cylinders (dia x stroke) (in / mm)16.14" x 23.62" / 410x600 (4)18.31" x 24.02" / 465x610
Tractive Effort (lbs / kg)25,976 / 11782.5319,817 / 8988.85
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.84 4.00
Heating Ability
Tubes (number - dia) (in / mm)129 - 1.772" / 45132 - 1.772" / 45
Flues (number - dia) (in / mm)28 - 4.921" / 12518 - 4.921" / 125
Flue/Tube length (ft / m)13.78 / 4.2016.40 / 5
Firebox Area (sq ft / m2)172.76 / 16.0596.34 / 8.95
Grate Area (sq ft / m2)29.71 / 2.7623.68 / 2.20
Evaporative Heating Surface (sq ft / m2)1488 / 138.241471 / 136.70
Superheating Surface (sq ft / m2)526 / 48.87378 / 35.12
Combined Heating Surface (sq ft / m2)2014 / 187.111849 / 171.82
Evaporative Heating Surface/Cylinder Volume133.02200.95
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation50834052
Same as above plus superheater percentage64054862
Same as above but substitute firebox area for grate area37,24519,781
Power L112,44612,328
Power MT824.241027.34

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