Twelve-Coupled Locomotives.

Updated: 25 Nov 2007

New:
Bulgarian Class 45 and Class 46 updated
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If a powerful locomotive is required, and the axle loading gets too great, the obvious solution is to add more wheels to distribute the load. If this is done with a rigid wheelbase it soon becomes impossible to get the machine round curves of a reasonable radius. Most railways took 10-coupled locomotives as the limit, but there were some successful rigid 12-coupled locomotives.

Here I have tried to assemble the complete collection of rigid wheelbase 12-coupled locomotives: moving-axle types, such as the Klien -Lindner Saxon 0-12-0T can be found on other pages. The collection ranges from huge mainline locomotives to small and highly specialised rack locos. It includes- perhaps surprisingly- what was arguably the most advanced steam locomotive ever built; see The SNCF 160-A-1 of 1940 below.

A further extension of the rigid-wheelbase principle to 14-coupled locomotives has only been attempted once, and that appears to have been once too often. See Stalin's Engine

The other approach to adding wheels is to use some form of articulation to give the whole assembly one or more hinges.


The first 12-coupled locomotive I have been able to discover was "Philadelphia" built in the USA by James Mulholland in 1863, for the Philadelphia & Reading Line. It was an 0-12-0 tank locomotive used for banking duties.

There is no place at the back for the fireman- there was no fireman. The loco was simply stoked up before each banking run.


1910

2-12-0

The Austrian State Railway S100
Engine weight:
94.25 tons
Coupled wheelbase:
26' 3"
Total wheelbase:
34' 5"
Boiler pressure:
235 psi
No of Cylinders:
4 compound
HP cylinders b x s:
17.75" x 26.75"
LP cylinders b x s:
29.87" x 26.75"
Driver diameter:
4' 9"
Power:
1800 HP
Builder:
Florisdorf

This was the first European 12-coupled tender engine and was considered the most powerful loco in Europe at the time. It was a 4-cylinder Gölsdorf compound built for the Arlberg line which had long 1:40 gradients and a limiting axle-load of 13.8 tonnes. All four cylinders drove the third coupled axle; the HP cylinders were inside. This was Gölsdorf's last compound; the design was not repeated, but it served as the basic model for the The Wurtemberg 2-12-0 of 1917. It gave "full satisfaction" according to André Chapelon and handled curves well; it was taken out of service in 1927 due to cylinder cracking.

Certain expedients were required to deal with 150 m radius curves:
Leading Bissel truck:
2" of side-play, no centering force.
First axle
No side-play
Second axle
1" of side-play, flangeless wheels
Third axle
Flangeless wheels
Fifth axle
1" of side-play
Sixth axle
1.5" of side-play
Carden universal joint in connecting rod between Fifth and Sixth axles


1912

0-12-0T

The Class 269 Austrian State Railway Zahnradlokomotive
Engine weight:
88 tons
Coupled wheelbase:
Total wheelbase:
Boiler pressure:
13 Bar
Adhesion cyls:
Stroke 570 mm
Rack cylinders:
Stroke 420 mm
Driver diameter:
1.05 m
Builder:
Florisdorf

The Austrian Erzbergbahn- the rack and adhesion railway over the Erzberg open-cast iron-ore mine- opened in 1891 to transport ore over the Präbichl Pass from the Erzberg to Virdernberg from where it was taken on to the blast furnaces at Donawitz. It was worked by 0-6-2T locomotives until the end of steam, but for hauling heavier trains over steeper sections, three locomotives of the new class 269 ( were delivered in 1912. They were larger and more powerful with six coupled axles, ie 0-12-0T. One (197.301) is preserved as a working locomotive in the Vienna Railway Museum at Strasshof.

197.301 at Strasshof

It appears to have grown two cylindrical tanks either side of the steam dome since the above picture was taken. Feedwater heaters?

Picture and additional info courtesy of John Ingham

The original Austrian class number of this design was 269, but this was changed to 97-3 after the anschluss with Germany in 1938, and again to class 197 when the ÖBB was set up after WW2.
Note that "twelve-coupled" in this case does not include the rack gearwheels. Zahnradlokomotive translates literally as "gear-wheel-locomotive" rather than "rack-locomotive."


1912

2-12-2T

Left: A Javanic: this 2-12-2T metre-gauge tank locomotive was built for use in Java.

Twelve-coupled locomotives were introduced on the Preanger Mountain Lines of the Java State Railways (Java is now part of Indonesia) after steam-pipe problems with Mallets of various sizes. 28 were built by Hanomag between 1912 and 1920. Although they coped with the work, the tight curves caused severe flange wear on the leading drivers, and they were moved to other mountain lines with milder curves, where they were very successful. Examples were working in Eastern Java up to the early 1970's.
The 2-12-2 configuration is called "Javanic" in the many tables of the Whyte system that have been published, but it is not exactly a word that is on everyone's lips. Two examples (F1002 and F1015) have been preserved in Indonesia, a country that seems to value its historic locomotives; F1002 (formerly SS class 817?) was built in 1915.

The series of 2-12-2 locomotives was ordered by the "Javaansche Staats Spoorwegen" (ie the State Railways of Java) which reported directly to the Dutch Minister of Transport; Java was a Dutch colony at the time. For those for whom God is in the details, the series was numbered 801-823 with subseries:
  • JSS 801-810 built by Hanomag 1912/13, build numbers 6450 and 6813-6821
  • JSS 811-816 built by Hanomag 1914/15, build numbers 7362-7367
  • JSS 817-819 built by Werkspoor 1915, build numbers 372-374
  • JSS 820-823 built by Werkspoor 1917, build numbers 418-421
For the railways on the Sumatran West coast an additional five locomotives were buil:
  • H 130-132, built by Werkspoor 1915, originally intended as JSS 820-822, build numbers 375-377
  • H 133-134, built by Hanomag 1920, build numbers 9353-9354
These last five loco's were shipped directly to Sumatra where they ran coal trains from the mines in the mountains to the seaports.

Left: F1002 preserved at Ambarawa Railway Museum in Java. It was built in 1913 by Hanomag. Javanic F1015 is also preserved.

Java, like the German states, has a rich history of unconventional locomotives, and for the same reasons- steep gradients and severe curves. Java boasted Mallets of various sizes, ten-coupled locos partly articulated with Klien-Lindner axles and Luttermöller axles, and rack-and-adhesion locomotives.
The loco had two outside cylinders of 540 x 510 mm. Driving wheel diameter was 1106 mm. Boiler pressure was 12.0 kg/cm2, The weight was 78.7 tons, of which 62.3 tons were available for adhesion.

Despite being a twelve-coupled design, this locomotive is not enormous. Remember it was built for the old 3ft 6in (1067 mm) "Cape gauge" much used in South Africa, and not the standard 4ft 8.5in.

Some technical details:

Cylinder diameter:
540 mm
Piston stroke:
510 mm
Wheel diameter:
1102 mm for coupled axles, 774 mm for the pony trucks
Overall length:
13.88 m
Boiler diameter:
1.40 m
Boiler length:
7.268 m
Boiler height (centreline):
2.45 m above railhead
Fixed wheelbase:
3.75 m, other driving wheels slide sideways, pony trucks are pivoted
Overall wheelbase:
10.25 m
Max. width:
2.506 m
Max. heigth:
3.70 m
Max speed:
55 km/h, later upgraded to 75 km/h. On trials 85 km/h.
Min. radius on curves:
140 metres
Gauge:
1.067 m (3ft 6in)

Left: Another view of F1002 at Ambarawa Railway Museum.

Later locomotives in this series were built by Werkspoor.

Colour pictures by kind permission of Rob Dickinson.
Original photography by Nick Bryant.

Further information on the Javanics would be most welcome.

Above: Side view of Javanic F1018. (Originally SS No 818) This is a Werkspoor version, built in 1915.

For much more on steam locomotives in java see Rob Dickinson's excellent site at: http://dialspace.dial.pipex.com/javatour/trains/pnkapres.htm


1917

2-12-0

The Würtemberg State Railway Group Class K
Engine weight:
108 tons
Coupled wheelbase:
Total wheelbase:
Boiler pressure:
213 psi
No of Cylinders:
4
HP cyls b x s:
20" x 25.5"
LP cylinders b x s:
30" x 25.5"
Driver diameter:
Builder:
Maschinenfabrik Esslingen

44 of these superheated four-cylinder compound locomotives were built. The inside HP cylinders drove the third coupled axle, while the outside LP cylinders drove the fourth. They became Class 59001/44 of the Reichsbahn.

Once again, there were certain expedients, this time to deal with curves of 105 m radius:
First axle
20mm of side-play
Third axle
Flanges thinned by 15mm
Fourth axle
Flanges thinned by 15mm
Sixth axle
45mm of side-play, spring lateral control when 28mm exceeded


1922

0-12-0T

The Bulgarian State Class 45

Class 45:00 were, apart from the number of wheels they had, standard gauge 2-cylinder compounds. There were not entirely satisfactory, being unstable on the track.

Engine weight:
101 tons
Length:
14.4 m
Coupled wheelbase:
7.225 m
Grate area:
4.6 m2
Evaporative area:
Original: 248.4 m2. Rebuilt: 181 m2 + superheat area 75 m2 = total heating area 256 m2
Boiler pressure:
15 bar ( psi)
No of Cylinders:
2
Left cylinder:
LP 900mm diam (Original)
Right cylinder:
HP 620mm diam
Piston stroke:
HP 700mm
Driver diameter:
1340 mm
Fuel & water:
Coal 5 ton, water 12 m3
Max speed:
45 km/h
Builder:
Hanomag

Arrangements for getting round curves were as follows:
The 1st and 6th axles had 28 mm of transverse movement.
The 3rd axle had 15 mm of transverse movement.
The 4th axle had flangeless wheels.
The 2nd and 5th axles had no transverse movement, defining the fixed wheelbase.

After WW2 they were transformed into 2-cylinder simple expansion locomotives, with two 620mm cylinders. This increased the tractive effort from 15.3 tons to 22.6 tons. hey were reconstructed in 1948 with Lentz poppet valves and Schmidt superheaters.

Technical information kindly supplied by Johannes Laeubli


1926

4-12-2

The Union Pacific Class 9000
Engine weight:
224.5 tons
Coupled wheelbase:
Total wheelbase:
Boiler pressure:
220 psi
No of Cylinders:
3
Inside cylinder:
27" x 31"
Outside cylinders:
27" x 32"
Driver diameter:
5' 7"
Power output:
4750 HP
Tractive effort:
96,650 lbs
Builder:
Alco
NB: There is some doubt about the cylinder dimensions.

These were the heaviest rigid steam locomotives produced in the USA; 88 were built for the UP by ALCO between 1926 and 1930. The original intended speed had been a modest 35 mph, but they proved stable up to 60 mph. After only ten years of main-line freight service in Oregon, Wyoming and Utah, these locomotives were relegated to slower operations in Nebraska, being displaced by Challengers and Big Boys.

Left: The preserved 9000.

One of these locomotives has been preserved at "The Los Angeles County Fairplex", the home of the Southern California Chapter of the Railway & Locomotive Historical Society. It is known as No 9000, so it appears to be the first member of the class. It arrived at the museum in May 1956 under its own power. This locomotive is said to have been in use for nearly 30 years, mainly between Green River, Wyoming and Council Bluffs, Iowa.

The inside cylinder drove the second coupled axle, and the outside cylinders the third. Kratville and Ranks give the weight including tender as 403.5 tons.

The 4-12-2 configuration became known as the "Union Pacific" wheel arrangement, because it was unique to UP. The locomotives were added to the UP roster as follows:

Year
How many
Numbers
1926
15
Nos 9000-9014.
1928
23
9015-9029 (15 locomotives), 9055-9062 (8 locomotives)
1929
25
9030-9054
1930
25
9078-9087 (10 locomotives), OSL 9500-9514 (15 locomotives)
Total
88
As to why the locomotives were numbered out of sequence, I have no idea.


1940

2-12-0

The SNCF 160-A-1 Six-cylinder Reheat Locomotive
Engine weight:
135.35 tons
Coupled wheelbase:
27' 4"
Total wheelbase:
35' 4.5"
Boiler pressure:
260 psi
No of Cylinders:
6
HP cylinders b x s:
520 x 540 mm
Outside LP cyls b x s:
640 x 650mm
Driver diameter:
1.4m
Builder:
SNCF
This remarkable locomotive deserves a website to itself. Its features included six cylinders and reheat. It was a rebuild of a Class-6000 2-10-0 by the great André Chapelon, for the Paris-Orleans Railway. Steam from the boiler passed through a 39 element Houlet superheater, and then to the two HP cylinders inside the frames which drove the fourth coupled axle. Steam leaving these passed through the reheater, which was essentially a Schmidt superheater with 68 elements. Two of the LP cylinders were also inside and drove the second coupled axle; the outside LP cylinders drove the third coupled axle. All cylinders had steam jackets. The various cranks were aligned to give six beats per revolution, smoothing the driving torque. Lentz oscillating-cam poppet valves were fitted.

Left: another view of the 160-A-1

The 160-A-1 was completed at the Tours works in 1940, but was not tested until 1948 due to WW2. It was extremely successful, according to M. Chapelon in his great book "La Locomotive A Vapeur", though it is just possible he was not completely impartial. It was however the last European 2-12-0 locomotive.

The 160-A-1 was a 'flying test-bed' and never intended for production. It was to provide data for a series of less complex locomotives with six cylinders; Chapelon published outline plans for these but none were built.


1941

2-12-2T

The Austrian Federal Railway Class 97.
Rack and adhesion system
Engine weight:
123.6 tons
Coupled wheelbase:
22' 10"
Total wheelbase:
37' 7"
Boiler pressure:
227 psi
Adhesion cylinders:
24" x 20.5"
Rack cylinders:
15.75" x 19.7"
Driver diameter:
3' 5.5'
Builder:
Florisdorf

Two of these locomotives, the heaviest and most powerful steam rack locomotive ever built, were delivered in 1941 for use on the Austrian Erzbergbahn. The engine has two pairs of cylinders, giving separate drive to the adhesion and rack driving wheels. They were capable of hauling a 300 tonne train up the steepest section of track at 15 km/h. However they were withdrawn early as they were unreliable and susceptible to derailment. The first was withdrawn in 1949 and used for spares to keep the other (297.401) running until 1968; the latter is now plinthed at Voredernberg-Markt station in Austria.

Left: A 160-A-1 plinthed at Vordernberg

The rack can be seen at the front of the loco, between the rails.

Photo kindly provided by John Ingham

Left: A 160-A-1 plinthed at Vordernberg

Rear view. Note the windows at the rear of the cab for running in reverse.

Photo kindly provided by John Ingham

Left: A 160-A-1 plinthed at Vordernberg

The complex mechanism of a combined rack and adhesion locomotive. Maintenance must have been interesting.

Photo kindly provided by John Ingham


1938/1942

2-12-4T

The Bulgarian State Class 46
The data just below apply to both batches.
Boiler pressure:
16 bar ( psi)
Grate area:
4.87 m2
Fuel & water:
Coal 10 ton, Water 18 m3
Driver diameter:
1340mm
Lead/trial wheel diam:
850mm
Max speed:
65 km/h

Apart from the number of axles, this design was a standard gauge superheated simple-expansion locomotive. The 3rd and 4th axles had flangeless wheels. Two batches were built, with some differences.

The first batch of 12 was built in 1931 by Cegielski Poznan (a company in Poland) as 4 501 - 512; from 1936 46 01 - 12 (Builder nos: 201 - 212). These had two cylinders of 700 mm diameter. Here are the details:

Engine weight:
149.1 metric tons
Adhesion weight
101.7 tons
Axle Load: Drivers:
17 tons
Coupled Wheelbase:
8 m
Total Wheelbase:
14,5 m
Total length:
18.205 m
Piston stroke:
700mm
Evaporation area:
224 m2 + superheating area 84 m2 = total heating area 308 m2
Tractive effort:
30.67 tons

The second batch of 8 was built by Schwartzkopff Berlin (of Germany) 46 13 - 20 (Builder nos: 11794-11801) These had three cylinders of 550 mm diameter. Here are the details:

Engine weight:
155.8 metric tons
Adhesion weight
108 tons
Axle Load: Drivers:
18 tons
Coupled Wheelbase:
7.85 m
Total Wheelbase: 1
4.45 m
Total length:
18.155 m
Piston stroke:
650mm
Evaporation area:
224 m2 + superheating area 82 m2 = total heating area 306 m2
Tractive effort:
26.4 tons

Technical information kindly supplied by Johannes Laeubli

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