Pf12

KFNB 226 (WrN 3801/1895), location and date unknown – probably a factory photo. This engine later became kkStB 308.02 and then ČSD 274.002; it was withdrawn in July 1926. Source: www.commons.wikimedia.org.

Side drawing of class 308; source: Triebfahrzeuge österreichischer Eisenbahnen: Dampflokomotiven BBÖ und ÖBB (see References).

KFNB No. 252 (Wiener Neustadt 4277/1900), probably a factory photo. Re-numbered 308.28, this locomotive remained in service until 1932. Source: Die Lokomotive July 1923.

An unidentified Class 227 locomotive (rebuilt from Class 308), location and date unknown. Source: as above.

BBÖ 308.506 (formerly KFNB No.276, WrN 4842/1908), Villach West station, July 22, 1934. Withdrawn in 1936. Photo by Viktor Konschegg (source: www.commons.wikimedia.org).

Ex-kkStB 308.09 and KFNB 233 (WrN 3876/1896) still with kkStB service number, photographed in Bielsko-Biała before 1926. Later this engine was re-numbered Pf12-1 and survived in service until December 1936. Source: www.historia.beskidia.pl.

First steam locomotives with the 2-2-1 axle arrangement, known as ‘Atlantics’, were built in 1887 in the USA for Atlantic Coast Railroad, hence its name. They were intended for fast passenger trains, but were soon found too weak, especially after heavier steel cars had become commonplace, and replaced by engines with three or more driven axles. In Europe the first railway to order Atlantics was Kaiser-Ferdinands-Nordbahn (KFNB) in Austro-Hungary, which, between 1895 and 1905, took delivery of 41 class IId engines from Wiener Neustadt, numbered 225 through 265. They featured 1960 mm drivers, single-expansion steam engines and run on saturated steam. After KFNB had been incorporated into state railways kkStB in 1907, these locomotives were re-classed 308. Four more examples, originally ordered by KFNB and numbered 266 through 269, were completed for the state railways. Individual batches differed in minor details. Further eighteen examples were built between 1898 and 1900 for Russian VVZhD (Warsaw-Vienna Railway) and numbered 214 through 231. Despite obsolescence of the basic design, twelve more engines were built for kkStB in 1908; they differed from their predecessors in being fitted with the Clench-type steam dryer, which, however, was found to be of little use and later removed. Initially these engines were numbered 270 through 281, although KFNB no longer existed as an independent company; later they were classed 308.5. All kkStB 308s were coupled with class 74 tenders, built in two variants. Between 1913 and 1916 three locomotives (308.12, 308.36 and 308.38) were extensively rebuilt and converted into the 2-3-0 axle arrangement with drivers reduced to 1614 mm in diameter. They were re-classed 227, their service numbers being retained.

After WWI all these engines were divided between Austria, Czechoslovakia and Poland. BBÖ took all 308.5s and 227s, as well as eighteen 308s. All retained their original service numbers. Only two remained in service for long enough to be taken over by DRG, namely 308.29 and 308.44, which became 14 001 and 14 002, respectively; in May 1941 both were converted into stationary boilers. ČSD acquired fifteen examples, classed 274.0. Their withdrawals started as early as in 1926 and the last one, 274.007, survived in service until May 1939.

During the 1915 German offensive all VVZhD engines were evacuated with retreating Russians. Ten were returned after the war, to be joined by nine examples from kkStB. All were classed Pf12. According to the monograph by Toms Altbergs (see References), of the remaining eight ex-VVZhD machines two were lost in Bukovina between 1916 and 1917 and four taken over by Soviet state railways; nothing is known of their subsequent fate. Two (former 219 and 228) were allegedly returned to Poland as frames and scrapped. Although not very old, these engines with two driven axles and running on saturated steam quickly became obsolete. Sixteen were withdrawn between 1927 and 1936. In September 1939 two (Pf12-2 and Pf12-19) were captured by the Soviets; the latter fell into German hands after Fall Barbarossa and was numbered 14 003, but saw no service. It was formally written off on December 13, 1951. Pf12-12, which became German booty, was soon withdrawn without being given new service number. No locomotive of this type has been preserved

Main technical data

No.	Parameter	Unit	Value
1.	Years of manufacture	-	1895 – 1908
2.	Total built / used in Poland	-	75 / 19
3.	Tender class	-	15C12
4.	Axle arrangement	-	2-2-1
5.	Design maximum speed	km/h	100
6.	Cylinder bore	mm	2 ´ 470
7.	Piston stroke	mm	600
8.	Engine rating	kW/hp	685 / 930
9.	Tractive effort	kG	5 600
10.	Boiler pressure	MPa	1.33
11.	Grate dimensions	m x m	2.90 m^2
12.	Firebox heating surface	m^2	12.20 /12.0^1)
13.	Distance between tube plates	mm	4100
14.	Number of flue tubes	-	230 / 229^1)
15.	Heating surface of flue tubes	m^2	156.50 / 156.40^1)
16.	Number of smoke tubes	-	-
17.	Heating surface of smoke tubes	m^2	-
18.	Evaporating surface, total	m^2	168.70 / 168.40^2)
19.	Superheater heating surface	m^2	-
20.	Diameter of drivers	mm	1960
21.	Diameter of idlers front/rear	mm	970 / 970
22.	Total weight, empty	kg	54 000 / 54 700^2) / 55 000^3)
23.	Total weight, working order	kg	67 800 / 68 300^2)
24.	Weight on drivers, working order	kg	28 000
25.	Weight with tender, empty	kg
26.	Weight with tender, working order^4)	kg	97 100^1) 97 700^2) / 98 000^3)
27.	Maximum axle load	T	14.0
28.	Axle base (with tender)	mm	13 896
29.	Overall length (with tender)	mm	16 998
30.	Brake type	-	Hardy

1) 308.13 through 45.

2) 308.13 through 27.

3) 308.28 through 45.

4) Higher by 400 kg with heavier tender variant.

List of vehicles can be found here.

References and acknowledgments

- LP, KT, EZ vol. 1;

- www.pl.wikipedia.org;

- Triebfahrzeuge österreichischer Eisenbahnen: Dampflokomotiven BBÖ und ÖBB by Heribert Schröpfer (Alba, 2002);

- Standard Gauge Locomotives in Russia and the Soviet Union by Toms Altbergs (Stenvalls, 2022);

- Monographic article in SS vol. 163.