Jura-Simplon / Swiss Federal 4-6-0 Locomotives in Switzerland


Class Details by Steve Llanso of Sweat House Media

Class 651 - Brotan (Locobase 10659)

Data from "New Locomotives, Swiss State Rys," The Locomotive Magazine, Volume XIV [14](15 July 1908), p. 121. (Brotan-Deffner details from Lance Day, Ian McNeil, Biographical dictionary of the history of technology (Chicago, IL: University of Chicago Press, 1996), p. 104. See also Douglas Self, [], last accessed 15 July 2009.) (Thanks to Ivo Rutishauser for his 24 February 2022 email offering additional information on all of the SBB 4-6-0s and, especially, for clearing up my confusion about which Locobase entry referred to which batch of the class.)

Essentially identical to the 701 class (Locobase 2584), this pair incorporated the Hungarian Brotan boiler in place of the conventional firebox. An excellent photograph on page 121 illustrates this unusual design, which is also described in Locobase 1580. Indeed, this was a variation on the Brotan conceived by the Swiss engineer E. Deffner that simplified and improved the basic idea, according to Day and McNeil.

The photo shows -- from bottom to top of the firebox -- a shallow, narrow grate out of which rose on each side three rows of water tubes that first ran vertically then curved out and back in (like a pair of steepled hands). All of the tubes met in the cylinder that topped the firebox, which stood for the area above the crown sheet in a conventional firebox. To this extent, Deffner followed Brotan. His innovation was to adopt a coned boiler forward of this assembly that allowed a direct connection between the Brotankessel and the rear tubeplate. According to Douglas Self, it was this version that appeared in most locomotives using the so-called Brotan boiler.

The pair were quite successful in service until their retirement in 1923.


Class A3/5 231/701 (Locobase 1469)

Data from A Ceresole "Locomotives Compound a quatre cylindres et a trois essieux couples", Bulletin technique de la Suisse romande, Volume 28, No 20 (20 Octobre 1902), pp. 261-262 . See also Gustav Reder (Michael Reynolds, trans), The world of steam locomotives (New York: Putnam, 1974), p 326 and Nock (RWC III, pl 176). (Thanks to Ivo Rutishauser for his 24 February 2022 email offering additional information on all of the SBB 4-6-0s and, especially, for clearing up my confusion about which Locobase entry referred to which batch of the class.)

Nock noted that the outside valve motion was Walschaert, but inside valves were actuated by Joy valve gear ("which had the attraction of saving space by needing no eccentrics"). This was a de Glehn compound, with the outside cylinders driving the second axle, the inside cylinders mounted slightly higher and turning the first axle.

A builder's photograph shows a lean profile accentuated by the long, thin boiler. Ceresole wrote that the requirement was for one locomotive to pull a 300 ton train up a 1% grade at 50 kph (31 mph). According to the same report, mounting the firebox over the axles meant that it was only slightly inclined. For firemen unused to firing large fireboxes, this constraint could make achieving a satisfactory fire more difficult. Moreover, Ceresole's observation that the roof of the firebox inclined toward the front to ensure the crown sheet was covered with water during steep ascents almost certainly added to the delicacy of the crew's judgement.

These two were the prototypes; see Locobase 2584 for the production variant. Rutishauser notes the two engines were never superheated and were retired and scrapped in 1928.


Class A3/5 501 (Locobase 8919)

Data from "3-Cylinder Simple Express Locomotives; Swiss Federal Railways", Railway Engineer, Volume XXX [30], No. 11, (November 1909). pp. 360-362. (Thanks to Ivo Rutishauser for his 24 February 2022 email offering additional information on all of the SBB 4-6-0s and, especially, for clearing up my confusion about which Locobase entry referred to which batch of the class.) Works numbers were 1859-1859 in 1907.

This three-cylinder simple-expansion design mirrored that of the four-cylinder Von Borries compounds described in Locobase 20985 by laying its three cylinders side-by-side under the smokebox, where they drove the leading coupled axle.

Inside-admission piston valves admitted the steam to all three cylinders. As RE analysed the motion, the outside valves were actuated by return shafts fitted to the driving crank pins. The movements were in the same plane as the crank bearings lined up exactly with the center of the piston valves. But the inside valve, placed as it was on the engine's centerline, had to be "set in stages from the eccentric, which is on the left side of the crank, to the centre line." For further details, Locobase refers the interested to p. 362 of the RE report.

Given the vast volume contained in three live cylinders fed by a relatively small boiler, Locobase suspects that this class fell far short of whatever expectations may have fueled its development. The last was retired in 1925.


Class A3/5 601 (Locobase 20985)

Data from "Notes on Swiss Locomotives Locomotives; Swiss Federal Railways", Railway Engineer, Volume XXX [30], No. 11 (November 1909). pp. 360-362. (Thanks to Ivo Rutishauser for his 24 February 2022 email offering additional information on all of the SBB 4-6-0s and, especially, for clearing up my confusion about which Locobase entry referred to which batch of the class.)Works numbers were 1856-1857 in 1907.

SLM built four copies of a new boiler and firebox. Two tested a three-cylinder simple-expansion power system; these are shown in Locobase 8919. The other two appear here as a four-cylinder compound design that differed from the 100+ 703 class in having a larger firebox and boiler and a von Borries four-abreast cylinder


Class A3/5 603 (Locobase 1468)

Data from "Notes on Swiss Locomotives", The Railway Engineer, Volume 29, No 11 (November, 1908), pp 353-354. See also "New Locomotives, Swiss Federal Rys", Locomotive Magazine, Volume XVIII [18] (14 September 1912), p. 188. (Thanks to Ivo Rutishauser for his 24 February 2022 email offering additional information on all of the SBB 4-6-0s and, especially, for clearing up my confusion about which Locobase entry referred to which batch of the class.)

Expansions of the 601-602 trial horses shown in Locobase 20985, these superheated Von Borries compounds presented a larger boiler, firebox, and grate, which was pressed to a higher bar. The 603s were arranged with all four cylinders in plane with each being actuated by a modified Walschaert gear operating a piston valve. The modification consisted of a single eccentric operating both the HP and LP valves on the same side, the differences in the timing and travel being worked out through separate lap and lead levers.

They were highly valued express engines and after electrification forced their retirement in Switzerland, almost half of the stud (21 locomotives) went to the Netherlands as their Series 35 engines. They were retired from that duty in 1952. The Wikipedia article on the class comments that in terms of years of operation and kilometers covered, these were the most successful Swiss express steam locomotives.


Class A3/5 703-saturated (Locobase 15562)

Data from Dr. R. Sanzin, "Die Lokomotiven auf der Intertionalen Austellung in Mailand 1906, 7. 2/4 gekuppelte vierzylindrige Verbund-Schnellzuglokomotive der Schweizer Bundesbahnen ...", Zeitschrift des Oesterreichischen Ingenieur- und Architeckten-Vereines, Volume LVIII [53]Nr. 51 (14 December 1906), p 714. (Thanks to Ivo Rutishauser for his 24 February 2022 email offering additional information on all of the SBB 4-6-0s and, especially, for clearing up my confusion about which Locobase entry referred to which batch of the class.) Works numbers were 1548-1550 , 1571-1574, 1602-1611 in 1904; 1731-1735, 1750-1763 in 1906; 1841-1853 in 1907; 1916-1946 in 1908; 2000-2005, 2009-2019 in 1909.

The largest single batch of 4-6-0s in Swiss service (where all 4-6-0s were designated 3/5 meaning 3 driving axles, 5 total), these engines began operating in 1902, when two prototypes entered service (See Locobase 1469). This entry covers the 107 production engines, delivered between 1904 and 1909.

In the SBB engines, the de Glehn design featured HP cylinders located outside driving the middle axle while the LP cylinders sat farther forward and turned the leading axle. Each of the four cylinders had its slide valve acuated separately, the HP cylinders being operated by Heusinger radial gear and the LPs operated by Joy valve gear.

703-748 trailed a two-bogie (four axles total) tender that held 18 cu m (4,755 US gallons) of water and 7 metric tons (7.7 short tons) of coal. 759-809's power system used a three-axle tender weighing 40,100 kg (88,405 lb) loaded with 17.8 cu m (4,703 US gallons) of water and 7.2 metric tons (7.9 short tons) of coal.

Superheaters were added between 1913 and 1933; see Locobase 15562.


Class A3/5 703-superheated-21 (Locobase 2584)

Data from "Locomotive pour trains rapides de la sTrie A 3/5, 703-748/-809", found at [], last accessed 17 January 2017. See also Gustav Reder (Michael Reynolds, trans), The world of steam locomotives (New York: Putnam, 1974), p 326; and Nock (RWC III, pl 176). (Thanks to Ivo Rutishauser for his 24 February 2022 email offering additional information on all of the SBB 4-6-0s and, especially, for clearing up my confusion about which Locobase entry referred to which batch of the class.)

Locobase 1429 gives details about the two prototype four-cylinder compound Ten-wheelers delivered in 1902 and 15562 describes the 107 saturated-boiler production series delivered from 1904-1909.

The SBB installed superheaters in 68 of the class from 1913 and 1933. 22 of the rebuilds received 21-element superheaters; the current entry shows the areas for that variant. The 46 fitted with 24-element systems appear in Locobase 20147.

Otherwise, noted the 705 site, the only change was to replace the HP piston valves with ones made from phosphor bronze. Combined with improved lubrication, the update increased available power by 10%. Walschaert's gear actuated the outside valves, Joy gear motivated the insided LP slide valves.

Ivo Rutishauser laid out the conversion schedule: "No. 728 being the first in 1913, 6 more from 1916 to 1918, and the rest 1920-1923."

He added: "Most engines were retired in the late 1920s and early 1930s, but a few soldiered on into the 1950s. No. 705 was withdrawn in 1964 and is now preserved in working condition.


Class A3/5 703-superheated-24 (Locobase 20147)

Data from "Locomotive pour trains rapides de la sTrie A 3/5, 703-748/-809", found at [], last accessed 17 January 2017. See also Gustav Reder (Michael Reynolds, trans), The world of steam locomotives (New York: Putnam, 1974), p 326; and Nock (RWC III, pl 176). (Thanks to Ivo Rutishauser for his 24 February 2022 email offering additional information on all of the SBB 4-6-0s and, especially, for clearing up my confusion about which Locobase entry referred to which batch of the class.)

Locobase 1429 gives details about the two prototype four-cylinder compound Ten-wheelers delivered in 1902 and 15562 describes the 107 saturated-boiler production series delivered from 1904-1909.

The SBB installed superheaters in 68 of the class from 1913 and 1933. 22 of the rebuilds received 21-element superheaters; the current entry shows the areas for that variant. The 46 fitted with 24-element systems appear in Locobase 20147.

Otherwise, noted the 705 site, the only change was to replace the HP piston valves with ones made from phosphor bronze. Combined with improved lubrication, the update increased available power by 10%. Walschaert's gear actuated the outside valves, Joy gear motivated the insided LP slide valves.

Ivo Rutishauser laid out the conversion schedule: "No. 728 being the first in 1913, 6 more from 1916 to 1918, and the rest 1920-1923."

He added: "Most engines were retired in the late 1920s and early 1930s, but a few soldiered on into the 1950s. No. 705 was withdrawn in 1964 and is now preserved in working condition.

Principal Dimensions by Steve Llanso of Sweat House Media

Class651 - BrotanA3/5 231/701A3/5 501A3/5 601A3/5 603
Locobase ID10659 1469 8919 20985 1468
RailroadSwiss Federal (SBB)Jura-Simplon (SBB)Swiss Federal (SBB)Swiss Federal (SBB)Swiss Federal (SBB)
CountrySwitzerlandSwitzerlandSwitzerlandSwitzerlandSwitzerland
Whyte4-6-04-6-04-6-04-6-04-6-0
Number in Class222249
Road Numbers651-652/801-811231-232/700-701501-502601-602603-649
GaugeStdStdStdStdStd
Number Built222249
BuilderSLMSLMSLMSLMSLM
Year19081902190819081910
Valve GearmixedvariousWalschaertWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)14.27 / 4.3512.80 / 3.9014.27 / 4.3514.27 / 4.3514.27 / 4.35
Engine Wheelbase (ft / m)28.05 / 8.5526.57 / 8.1027.72 / 8.4527.72 / 8.4528.38 / 8.65
Ratio of driving wheelbase to overall engine wheelbase 0.51 0.48 0.51 0.51 0.50
Overall Wheelbase (engine & tender) (ft / m)50.20 / 15.3050.52 / 15.4050.52 / 15.40
Axle Loading (Maximum Weight per Axle) (lbs / kg)35,935 / 16,30033,951 / 15,40033,731 / 15,30035,274 / 16,000
Weight on Drivers (lbs / kg)100,751 / 45,70099,208 / 45,000100,035 / 45,375100,751 / 45,700105,601 / 47,900
Engine Weight (lbs / kg)143,521 / 65,100143,300 / 65,000147,214 / 66,775151,898 / 68,900160,937 / 73,000
Tender Loaded Weight (lbs / kg)89,508 / 40,60084,878 / 38,50084,651 / 38,39784,657 / 38,40092,153 / 41,800
Total Engine and Tender Weight (lbs / kg)233,029 / 105,700228,178 / 103,500231,865 / 105,172236,555 / 107,300253,090 / 114,800
Tender Water Capacity (gals / ML)4699 / 17.804488 / 174699 / 17.804646 / 17.604752 / 18
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 7.70 / 7 4.40 / 4 7.70 / 7 5.50 / 5 7.70 / 7
Minimum weight of rail (calculated) (lb/yd / kg/m)56 / 2855 / 27.5056 / 2856 / 2859 / 29.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)70.10 / 178070 / 177870.10 / 178170.10 / 178070.10 / 1780
Boiler Pressure (psi / kPa)220.50 / 15.20224.80 / 15.50169.70 / 11.70188.50 / 13203.10 / 14
High Pressure Cylinders (dia x stroke) (in / mm)14.17" x 25.98" / 360x66014.17" x 24.02" / 360x61018.5" x 25.98" / 470x660 (3)16.73" x 25.98" / 425x66016.73" x 25.98" / 425x660
Low Pressure Cylinders (dia x stroke) (in / mm)22.44" x 25.98" / 570x66022.44" x 24.02" / 570x61024.8" x 25.98" / 630x66024.8" x 25.98" / 630x660
Tractive Effort (lbs / kg)19,943 / 9046.0018,824 / 8538.4327,445 / 12448.8622,845 / 10362.3324,614 / 11164.74
Factor of Adhesion (Weight on Drivers/Tractive Effort) 5.05 5.27 3.64 4.41 4.29
Heating Ability
Tubes (number - dia) (in / mm)230 - 1.969" / 50236 - 1.811" / 46127 - 1.969" / 50127 - 1.969" / 50152 - 1.969" / 50
Flues (number - dia) (in / mm)21 - 5.236" / 13321 - 5.236" / 13321 - 5.236" / 133
Flue/Tube length (ft / m)14.47 / 4.41 / 413.78 / 4.2013.78 / 4.2014.76 / 4.50
Firebox Area (sq ft / m2)193.75 / 18141.01 / 13.10166.84 / 15.50166.84 / 15.50166.84 / 15.50
Grate Area (sq ft / m2)26.91 / 2.5028.20 / 2.6227.99 / 2.6027.99 / 2.6030.14 / 2.80
Evaporative Heating Surface (sq ft / m2)1905 / 1771817 / 168.801462 / 135.821454 / 135.101739 / 161.60
Superheating Surface (sq ft / m2)404 / 37.53405 / 37.60456 / 42.40
Combined Heating Surface (sq ft / m2)1905 / 1771817 / 168.801866 / 173.351859 / 172.702195 / 204
Evaporative Heating Surface/Cylinder Volume401.74414.44120.59219.97263.08
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation59346339475052766121
Same as above plus superheater percentage59346339579564377407
Same as above but substitute firebox area for grate area42,72231,69934,54238,36841,001
Power L1622560169701899610,908
Power MT408.64401.07641.39590.55683.18

Principal Dimensions by Steve Llanso of Sweat House Media

ClassA3/5 703-saturatedA3/5 703-superheated-21A3/5 703-superheated-24
Locobase ID15562 2584 20147
RailroadSwiss Federal (SBB)Swiss Federal (SBB)Swiss Federal (SBB)
CountrySwitzerlandSwitzerlandSwitzerland
Whyte4-6-04-6-04-6-0
Number in Class1092246
Road Numbers703-809703-809703-809
GaugeStdStdStd
Number Built109
BuilderSLMSBBSBB
Year190419131916
Valve Gearvariousvariousvarious
Locomotive Length and Weight
Driver Wheelbase (ft / m)12.80 / 3.9014.27 / 4.3514.27 / 4.35
Engine Wheelbase (ft / m)26.57 / 8.1027.40 / 8.3527.40 / 8.35
Ratio of driving wheelbase to overall engine wheelbase 0.48 0.52 0.52
Overall Wheelbase (engine & tender) (ft / m)50.20 / 15.3050.20 / 15.30
Axle Loading (Maximum Weight per Axle) (lbs / kg)35,274 / 16,00035,274 / 16,000
Weight on Drivers (lbs / kg)101,413 / 46,000105,381 / 47,800105,381 / 47,800
Engine Weight (lbs / kg)141,426 / 64,150148,591 / 67,400148,591 / 67,400
Tender Loaded Weight (lbs / kg)82,673 / 37,50094,799 / 43,00094,799 / 43,000
Total Engine and Tender Weight (lbs / kg)224,099 / 101,650243,390 / 110,400243,390 / 110,400
Tender Water Capacity (gals / ML)4488 / 174699 / 17.804699 / 17.80
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 4.40 / 4 7.70 / 7 7.70 / 7
Minimum weight of rail (calculated) (lb/yd / kg/m)56 / 2859 / 29.5059 / 29.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)70.10 / 178070.10 / 178070.10 / 1780
Boiler Pressure (psi / kPa)217.60 / 15224.80 / 15.50224.80 / 15.50
High Pressure Cylinders (dia x stroke) (in / mm)14.17" x 25.98" / 360x66014.17" x 25.98" / 360x66014.17" x 25.98" / 360x660 (4)
Low Pressure Cylinders (dia x stroke) (in / mm)22.44" x 25.98" / 570x66022.44" x 25.98" / 570x66022.44" x 25.98" / 570x660
Tractive Effort (lbs / kg)19,680 / 8926.7120,331 / 9222.0030,497 / 13833.22
Factor of Adhesion (Weight on Drivers/Tractive Effort) 5.15 5.18 3.46
Heating Ability
Tubes (number - dia) (in / mm)236 - 1.969" / 50127 - 1.969" / 50110 - 1.969" / 50
Flues (number - dia) (in / mm)21 - 5.236" / 13324 - 5.236" / 133
Flue/Tube length (ft / m)13.78 / 4.2013.78 / 4.20
Firebox Area (sq ft / m2)166.84 / 15.50157.15 / 14.60157.15 / 14.60
Grate Area (sq ft / m2)29.28 / 2.7227.99 / 2.6027.99 / 2.60
Evaporative Heating Surface (sq ft / m2)1817 / 168.801445 / 134.271391 / 129.20
Superheating Surface (sq ft / m2)405 / 37.60497 / 46.20
Combined Heating Surface (sq ft / m2)1817 / 168.801850 / 171.871888 / 175.40
Evaporative Heating Surface/Cylinder Volume383.18304.73146.67
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation637162926292
Same as above plus superheater percentage637176767928
Same as above but substitute firebox area for grate area36,30443,09944,512
Power L1566812,97714,686
Power MT369.65814.45921.71

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