Swiss Federal 2-10-0 Locomotives in Switzerland

Class Details by Steve Llanso of Sweat House Media

Class Series 5/6 Elefant - simple (Locobase 8796)

Data from "2-10-0 Simple Expansion and Compound Locomotive, Swiss Federal Railways", Railway Engineer, Volume 36, No. 1 (January 1915), pp. 12-13.

OS Nock (RWC IV, pl 172) explains that the first three compound engines competed against two others of identical design except for the latter's four-cylinder simple-expansion layout. Although Nock writes that "the eventual outcome is not widely known," these two simple-expansion engines were the only ones of the type to be built.

Nock is not quite correct in asserting that they were identically built. The tubes in the simple-expansion engines were longer and thus created more boiler heating surface; the pressure setting, however, was 2 atm lower. In addition, water for the simple pair was preheated by a feed water heater whose tubes presented 23.4 sq m (252 sq ft) of surface area. The double valves, each of which served the two cylinders on each side of the centerline, measured 250 mm (9.87") in diameter.

Locobase 2524 describes the triumphant compounds.

Class Series 5/6 Elefant - verbund (Locobase 2524)

Data from Max Weiss, Vierzylinder-Heissdampf-Gnterzuglokomotive der Schweizerischen Bundesbahnen, Serie 5/6, Schweizerische Bauzeitung (Volume 63, Nr 17, 25 April 1914), pp.235-241, obtained from See also "2-10-0 Goods Engine, Gothard [sic] Section, Swiss Federal Railways", Locomotive Magazine, Volume XX [20] (15 March 2014), p. 72; "Swiss Decapod Locomotive in Service on the Paris, Lyons and Mediterranean Ry." Locomotive Magazine, Volume XXIII [23] (15 June 1917), p. 110; and [] (accessed 27 December 2006). (Thanks to Alexander Blessing for his 28 April 2019 email correcting the original description of the compounds' valve gear setup.)

OS Nock (RWC IV, pl 172) explains that the first three engines competed against two others of identical design except for the latter's two-cylinder simple-expansion layout (see Locobase 8976). Although Nock writes that "the eventual outcome is not widely known," because of the First World War and electrification, it's clear that the choice was compounding, for 27 more were supplied. This batch included the very last steam locomotive built for the Swiss Federal railroads.

[] (reviewed 15 Feb 2004) describes a large von Borries compound that outstripped all other Swiss steam locomotives in power. Alexander Blessing's email pointed out that this design was an example of a von Borries compound. Each of the four cylinders had its own valve; the inside HP cylinder valves were operated through a rocker arm reaching in from the valve gear mounted outside. The inside, HP cylinders drove the second axle, the outside, LP cylinder turned the drivers on the third axle.

The Elefants' also had a feedwater heater (speissewasser vorwarmer) and a rauchkammer vorwarmer (smokebox preheater).

Intended for work on the steep grades of the Gotthard line, they were rated at 320 tons of freight traveling 26 km/h (15 mph). For the faster passenger service, the tonnage rating dropped to 200 tons.

As France's involvement in World War One deepened, the PLM began suffering from a power shortage and Switzerland feared a food shortage. So the Swiss Federal Railways arranged a loan of locomotives and crews to run trains of foodstuffs to the Swiss border.

The Elefants worked the heavy sections between Geneva in Switzerland and Amberieu in France. They hauled a typical train load of 650 tons up the 1.25% grade.

After the extensive electrification of much of the Swiss railway system, these engines saw further service on the flatter stretches. Some were lent (after pressure was brought to bear) to Nazi Germany during World War II, but none was lost. Post-war France operated several between Geneva and Toulon, Marseilles, and Sete.

In 1953, the SBB converted the 2976 to burn oil using the Sprenger system. Its new fuel earned it the nickname "oil-ephant". Advantages included simpler, cleaner operation, but the SBB soon retired all of its steam locomotives.

In one way or another, locomotives of this class persisted in operation until the late 1960s, with 2969 pulling the last steam-hauled train in officially scheduled service on 30 November 1969.

2978, the last to be completed, was preserved and participates in tourist service. Its care falls to Dampfgruppe Znrich; the 2978 is based at Brugg (AG).

Principal Dimensions by Steve Llanso of Middle Run Media

ClassSeries 5/6 Elefant - simpleSeries 5/6 Elefant - verbund
Locobase ID8796 2524
RailroadSwiss FederalSwiss Federal
Number in Class230
Road Numbers2954-29552951-2953, 2956-2978
Number Built230
Valve GearWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)21.16 / 6.4521.16 / 6.45
Engine Wheelbase (ft / m)28.87 / 8.8028.87 / 8.80
Ratio of driving wheelbase to overall engine wheelbase 0.73 0.73
Overall Wheelbase (engine & tender) (ft / m)52.02 / 15.8652.02 / 15.86
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)166,669 / 75,600167,800 / 76,113
Engine Weight (lbs / kg)188,054 / 85,300189,189 / 85,815
Tender Loaded Weight (lbs / kg)92,153 / 41,80092,153 / 41,800
Total Engine and Tender Weight (lbs / kg)280,207 / 127,100281,342 / 127,615
Tender Water Capacity (gals / ML)4752 / 184752 / 18
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 8.80 / 8 8.80 / 8
Minimum weight of rail (calculated) (lb/yd / kg/m)56 / 2856 / 28
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)52.40 / 133052.40 / 1330
Boiler Pressure (psi / kPa)188.50 / 13224.80 / 15.50
High Pressure Cylinders (dia x stroke) (in / mm)18.5" x 25.2" / 470x640 (4)18.5" x 25.2" / 470x640
Low Pressure Cylinders (dia x stroke) (in / mm)27.95" x 25.2" / 710x640
Tractive Effort (lbs / kg)52,744 / 23924.3043,739 / 19839.70
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.16 3.84
Heating Ability
Tubes (number - dia) (in / mm)187 - 1.969" / 50187 - 1.969" / 50
Flues (number - dia) (in / mm)24 - 5.236" / 13324 - 5.236" / 133
Flue/Tube length (ft / m)17.22 / 5.2516.40 / 5
Firebox Area (sq ft / m2)147.41 / 13.70147.47 / 13.70
Grate Area (sq ft / m2)39.81 / 3.7039.83 / 3.70
Evaporative Heating Surface (sq ft / m2)2380 / 221.202275 / 211.35
Superheating Surface (sq ft / m2)619 / 57.50586 / 54.45
Combined Heating Surface (sq ft / m2)2999 / 278.702861 / 265.80
Evaporative Heating Surface/Cylinder Volume151.78290.18
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation75048954
Same as above plus superheater percentage908010,745
Same as above but substitute firebox area for grate area33,62239,782
Power L191219091
Power MT603.24597.21

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