Bavarian State 4-6-2 Locomotives in Germany


Class Details by Steve Llanso of Sweat House Media

Class BR 18.6 (Locobase 5940)

See Locobase 2533 for a discussion of the line of Pacifics procured by this railway. Christian Lindecke -- [] (viewed 13 Dec 2003) -- supplies data and information for this rebuild program. Supplemented by [], last accessed 11 May 2011

In 1953, the latest group of S 3/6 engines (Locobase 5939) was taken in hand for reconstruction. A new boiler was mounted that had a smaller firebox and less superheat.


Class Group S3/6a,b,c, f, h/ BR 18.4 (Locobase 2533)

Data from Gustav Reder (translated by ), World of Steam Locomotives (1974). See also the German-language "Neu Heissdampf-Pacific-Schnellzuglokomotive der kgl. Bayerischen Staatsbahnen", Die Lokomotive, Volume 11, No 1 (Janner/January 1914), pp. 2-8, archived at the Oesterreich Nationalbibliotek at [], last accessed 19 October 2022. Works numbers were 3016-3022 in 1908, 3088-3097 in 1909, 3142 in 1910, 3449-3451 in 1913, 3482-3486 in 1914.

A world-famous design by Maffei's Anton Hammel, this engine bore many similarities to the slightly earlier, and less successful, Group IV engines of the Baden State. (Like the Group IVs, the HP and LP stroke lengths differed, as shown in the specs.) Gustav Reder wrote that it was one of the most economical engines of its day. "But the main factor in its fame was its striking appearance. Even the English, who were very keen on this point, count it among the most beautiful engines ever built." For one thing, the smokebox cover had a conical fairing that enhanced the image of streamlined grace. Tufnell (1986) says that this design was known as the "Magnificent Maffei" and says that 159 were delivered.

Die Lokomotive's report

[] offers the following breakdown of batches and years:

S 3/6, S 3/6 a,b,c - Nr. 18 401 - 18 418 1908 - 1911 (this entry)

S 3/6 f,g, h - Nr. 18 419 - 18 434 1913 - 1914 (this entry)

S 3/6 d,e - Nr.18 441 - 18 458 1912 - 1913 (Locobase 5937)

S 3/6 j - Nr. 18 461 - 18 478 1915 - 1918 (Locobase 5941)

S 3/6 k - Nr. 18 479 - 18 508 1923 - 1924 (Locobase 5938)

S 3/6 l, m - Nr. 18 509-18.530 1926-1930 (Locobase 21099)

Class numbers 18 435 - 18 440 weren't produced.

In addition to those built for Bavarian State and the German National Railroads, the Madrid-Zaragoza-Alicante took four and Romanian railways received 80 similar engines that were 4-cylinder simples.

Pierre Birge' responded to an inquiry on John Oxlade's World Railway Forum -- [] (visited 2 March 2004) with details about the French-German Pacifics. Of this first batch, 4 went to the Etat in France as part of reparations for World War I. In Bavarian service they carried numbers 3602 (works #3017), 3650 (#3020), 3618 (#3142), and 3622 (#3159). Their numbers were Etat 231.981-231.984. In January 1938, the SNCF absorbed the Etat and this quartet was renumbered in the 3-231 A 981 to 3 231 A 996.

After Germany took France, the locomotives were eventually taken back to Munich. Service on German railways finished off the 15 survivors which were in such bad condition that they were stored and scrapped in 1950.


Class Group S3/6d,e / BR 18.4 (Locobase 5937)

Data from Christian Lindecke -- [] (viewed 13 December 2003); and "Baureihe 18.4" (1912) in Alfred Gieseler's Dampfmaschinen und Lokomotiven website at [], last accessed 19 October 2022. For these two batches in particular, see also the German-language "Neu Heissdampf-Pacific-Schnellzuglokomotive der kgl. Bayerischen Staatsbahnen", Die Lokomotive, Volume 11, No 1 (Janner/January 1914), pp. 2-8, archived at the Oesterreich Nationalbibliotek at [], last accessed 19 October 2022.

See Locobase 2533 for a discussion of the line of Pacifics procured by this railway. -- Lindecke noted these had had taller drivers, which led to raising the boiler center 65 mm (2.6") and a longer rigid wheelbase of 2,030 mm (6 ft 8"). Also the taller drivers meant a longer HP stroke, which in this sub-class only was nearly equal to that of the LP cylinders. The class was rated at 148 km/h (92 mph).

As with the other Bavarians, the whole class was taken up by the DRG, in this case receiving numbers 18 441-18 458. The last of the class was withdrawn in 1954.

The Deutsche Museum site -- [], accessed 7 July 2006 -- describes the prodigies of long-distance running of which this design was capable:

"In May 1951, it achieved a unique long-distance record: 820 km [509 miles] from Hamburg to Munich, pulling an express train weighing 150 t! It had to take in water several times on its route, but the coal lasted until the locomotive reached its destination. The builders were intent on proving that steam locomotives are not inferior to electric and diesel locomotives on long routes."

The Deutsche Museum adds a comment about the relative fuel efficiency of this design: "With regard to steam locomotives, the S 3/6 was Germany's most economical piece of rolling stock in express operation. It consumed between 1.2 and 2.3 tons of coal for a total distance covered of 100 kilometres - an average of 5.5 kg [19.5 lb] per passenger. This corresponds to the fuel consumption of a modern car!"


Class Group S3/6i,j / BR 18.4 (Locobase 5941)

See Locobase 2533 for a discussion of the line of Pacifics procured by this railway. Data from Christian Lindecke -- [] (viewed 13 December 2003) -- for data and information on this subclass. Supplemented by [], last accessed 11 May 2011. See also Pierre Birge' responded to an inquiry on John Oxlade's World Railway Forum -- [] (visited 2 March 2004; link removed from the Web in 2017). Works numbers 4513-4517 in 1914, 4518-4522 in 1917, and 4523-4542 in 1918.

After the Pfalzbahn bought a set of 10 S 3/6, the K.Bay.Sts.B followed up with these wartime batches. Possibly because of lack of access to stronger materials because of blockades, these engines weighed somewhat more than the earlier variants.

Pierre Birge' responded to an inquiry on World Railway Forum with details about the French-German Pacifics. As part of German war reparations owed after World War I, twelve of this group went to France in 1919 (four others were from earlier batches). In Bavarian service they carried numbers 3665-3679 (works numbers were 4528-4529, 4531-4533, 4535, 4537-4542). Their numbers were Etat 231.985-231.996. In January 1938, the SNCF absorbed the Etat and all of the reparations locomotives were numbered in the 3-231 A 981 to 3 231 A 996 range.

After Germany took France, the locomotives were eventually taken back to Munich. Service on German railways finished off the 15 survivors which were in such bad condition that they were stored and scrapped in 1950.

The other 18 were taken in the DRG as DRG 18 461-478.


Class Group S3/6k / BR 18.4 (Locobase 5938)

See Locobase 2533 for a discussion of the line of Pacifics procured by this railway. Christian Lindecke -- [] (viewed 13 Dec 2003), supplemented by [], last accessed 11 May 2011.

Lindecke notes that this class was ordered to satisfy a shortage of express passenger locmotives during the transition to a national railway system. Note that the boiler and grate had the same heating surface dimensions as the 1912 d/e subclass.

As with the others in this line, these were very satisfactory and continued in service until 1960.


Class Group S3/6l, m, n, o /BR 18.5 (Locobase 21099)

See Locobase 2533 for a discussion of the line of Pacifics procured by this railway. Data from "Baureihe 18.5" [], last accessed 11 May 2011; and "Bayerische S 3/6" in Wikipedia at [],_m,_n_und_o, last accessed 19 October 2022. Maffei Munich works numbers were (1) 5661-5672 in 1926, (m) 5689-5696 in 1927, (n) 5873-5874 in 1930. (Maffei entered bankruptcy at that point and Henschel & Sohn completed (o) with their works numbers 21731-21748 in 1930

Lindecke wrote that this class was ordered from Maffei and Henschel to satisfy a shortage of express passenger locomotives during the transition to a national railway system. Note that the boiler and grate had the same heating surface dimensions as the 1912 d/e subclass. One noticeable difference was the modest 15 mm increase in high-pressure cyinder diameters. (Wikipedia claims an increase in superheater area, but Locobase couldn't find confirmation.)

As with the others in this line, these were very satisfactory and continued in service until 1960.

Principal Dimensions by Steve Llanso of Middle Run Media

ClassBR 18.6Group S3/6a,b,c, f, h/ BR 18.4Group S3/6d,e / BR 18.4Group S3/6i,j / BR 18.4Group S3/6k / BR 18.4
Locobase ID5940 2533 5937 5941 5938
RailroadBavarian StateBavarian StateBavarian StateBavarian StateBavarian State
CountryGermanyGermanyGermanyGermanyGermany
Whyte4-6-24-6-24-6-24-6-24-6-2
Number in Class3031183030
Road Numbers18 601-18 6303601-3623, 3642-36493624-3641/BR 18.441-18.4583650-3679/18 461-18 4783680-3709/18 479-508
GaugeStdStdStdStdStd
Number Built31183030
BuilderseveralMaffeiHenschel & SohnMaffeiMaffei
Year19531908191219141923
Valve GearWalschaertWalschaertWalschaertWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)13.65 / 4.1613.65 / 4.16
Engine Wheelbase (ft / m)36.71 / 11.1937.27 / 11.3637.47 / 11.4236.71 / 11.1936.71 / 11.19
Ratio of driving wheelbase to overall engine wheelbase 0.37 0.36
Overall Wheelbase (engine & tender) (ft / m)63.97 / 19.5061.81 / 18.8460.51 / 18.4460.51 / 18.44
Axle Loading (Maximum Weight per Axle) (lbs / kg)41,667 / 18,90039,683 / 18,00036,817 / 16,70037,479 / 17,00038,801 / 17,600
Weight on Drivers (lbs / kg)124,781 / 56,600109,349 / 49,600105,822 / 48,000112,436 / 51,000116,183 / 52,700
Engine Weight (lbs / kg)221,123 / 100,300194,668 / 88,300197,313 / 89,500203,486 / 92,300207,234 / 94,000
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)
Tender Water Capacity (gals / ML)8369 / 31.707239 / 27.428448 / 326970 / 26.407234 / 27.40
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 9.90 / 9 9.90 / 9 9.40 / 8.50 8.80 / 8 9.40 / 9
Minimum weight of rail (calculated) (lb/yd / kg/m)69 / 34.5061 / 30.5059 / 29.5062 / 3165 / 32.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)73.60 / 187073.60 / 187078.70 / 200073.60 / 187073.60 / 1870
Boiler Pressure (psi / kPa)232.10 / 16224.80 / 15.50217.60 / 15232.10 / 16232.10 / 16
High Pressure Cylinders (dia x stroke) (in / mm)17.32" x 24.02" / 440x61016.73" x 24.02" / 425x61016.73" x 26.38" / 425x67016.73" x 24.02" / 425x61016.73" x 24.02" / 425x610
Low Pressure Cylinders (dia x stroke) (in / mm)25.59" x 26.38" / 650x67025.59" x 24.02" / 650x61025.59" x 26.38" / 650x67025.59" x 26.38" / 650x67025.59" x 26.38" / 650x670
Tractive Effort (lbs / kg)27,259 / 12364.4924,456 / 11093.0724,314 / 11028.6625,945 / 11768.4725,945 / 11768.47
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.58 4.47 4.35 4.33 4.48
Heating Ability
Tubes (number - dia) (in / mm)139 - 2.008" / 51130 - 2.126" / 54130 - 2.205" / 56130 - 2.126" / 54130 - 2.126" / 54
Flues (number - dia) (in / mm)35 - 5.63" / 13835 - 5.433" / 13835 - 5.433" / 13835 - 5.433" / 13835 - 5.433" / 138
Flue/Tube length (ft / m)16.40 / 517.26 / 5.2617.26 / 5.2617.26 / 5.2617.26 / 5.26
Firebox Area (sq ft / m2)237.04 / 22.03154.57 / 14.36151.02 / 14.03154.57 / 14.36154.51 / 14.36
Grate Area (sq ft / m2)44.01 / 4.0948.76 / 4.5348.76 / 4.5348.76 / 4.5348.74 / 4.53
Evaporative Heating Surface (sq ft / m2)2113 / 196.402125 / 197.412125 / 197.402125 / 197.412124 / 197.41
Superheating Surface (sq ft / m2)792 / 73.60798 / 74.16798 / 74.16798 / 74.16798 / 74.16
Combined Heating Surface (sq ft / m2)2905 / 2702923 / 271.572923 / 271.562923 / 271.572922 / 271.57
Evaporative Heating Surface/Cylinder Volume322.59347.71316.60347.71347.55
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation10,21510,96110,61011,31711,313
Same as above plus superheater percentage12,97313,92113,47514,37314,367
Same as above but substitute firebox area for grate area69,87244,12941,73545,56245,544
Power L118,90319,44018,28918,27518,273
Power MT1001.931175.811143.061075.001040.21

Principal Dimensions by Steve Llanso of Middle Run Media

ClassGroup S3/6l, m, n, o /BR 18.5
Locobase ID21099
RailroadBavarian State
CountryGermany
Whyte4-6-2
Number in Class32
Road Numbers3680-3709/18 509-18.530, 18.531-18.543
GaugeStd
Number Built32
Builderseveral
Year1926
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)
Engine Wheelbase (ft / m)36.71 / 11.19
Ratio of driving wheelbase to overall engine wheelbase
Overall Wheelbase (engine & tender) (ft / m)60.51 / 18.44
Axle Loading (Maximum Weight per Axle) (lbs / kg)39,463 / 17,900
Weight on Drivers (lbs / kg)116,183 / 52,700
Engine Weight (lbs / kg)207,234 / 94,000
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)
Tender Water Capacity (gals / ML)7234 / 27.40
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 9.90 / 9
Minimum weight of rail (calculated) (lb/yd / kg/m)65 / 32.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)73.60 / 1870
Boiler Pressure (psi / kPa)232.10 / 16
High Pressure Cylinders (dia x stroke) (in / mm)16.73" x 24.02" / 440x610
Low Pressure Cylinders (dia x stroke) (in / mm)25.59" x 26.38" / 650x670
Tractive Effort (lbs / kg)25,945 / 11768.47
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.48
Heating Ability
Tubes (number - dia) (in / mm)130 - 2.126" / 54
Flues (number - dia) (in / mm)35 - 5.433" / 138
Flue/Tube length (ft / m)17.26 / 5.26
Firebox Area (sq ft / m2)154.57 / 14.36
Grate Area (sq ft / m2)48.76 / 4.53
Evaporative Heating Surface (sq ft / m2)2125 / 197.41
Superheating Surface (sq ft / m2)798 / 74.16
Combined Heating Surface (sq ft / m2)2923 / 271.57
Evaporative Heating Surface/Cylinder Volume347.71
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation11,317
Same as above plus superheater percentage14,373
Same as above but substitute firebox area for grate area45,562
Power L118,275
Power MT1040.33

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