Pn11
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Pn11-8 (ex 210.09, BMMF
358/1910), photographed in Kraków in March 1937.
Source: National Digital Archives (www.nac.gov.pl). Used by permission. This
engine was returned by DR in 1955 and scrapped.
An unidentified kkStB 210; location and date unknown.
Source: Die Lokomotive
December 1910. |
Development
of steam locomotives in Austro-Hungary was influenced by two important
factors: comparatively poor quality of many tracks and low calorific value of
domestic coals. The former implied axle load limit of 14.5 tonnes; the latter called for large fireboxes, in order
to achieve sufficient steam production and parameters. These factors
influenced the Austrian school of locomotive design. Many achievements of
this school are connected with the name of Karl Gölsdorf
(1861-1916). During
the last decade of the 19th century there was a considerable
tendency to increase speed and comfort of the most prestigious passenger
trains, which resulted in many new designs. Austro-Hungarian state railways kkStB (Kaiserlich-königliche
österreichische Staatsbahnen)
were no exception, although the above-mentioned factors resulted in somewhat
specific design features. These were clearly seen in the first express
locomotive standardized by this service, class 6. Designed by Gölsdorf, it went into production at three factories (WLF,
Wiener Neustadt and StEG) in 1894 and
during next four years 68 examples were built. This machine had high-pitched
boiler and large drivers (2000 mm in diameter), which provided space for a
huge firebox. Despite quite good performance, class 6, with two driven axles,
soon became obsolete. It was developed further, into classes 106 (126
examples), 206 (89 examples) and 306 (only five); while retaining the same
axle arrangement (2-2-0), 2100 mm drivers and general layout, they differed
considerably, but soon it became evident that more powerful machines were
necessary. It was not possible to maintain low axle load while substantially
increasing boiler size and capacity with the 2-2-0 arrangement, so new
designs concepts were tried: class 9 (2-3-0), class 108 (2-2-1), class 110
(1-3-1) and class 280 (1-5-0). In
1906, Gölsdorf began to design a new express
locomotive, intended to haul trains of overall weight 400 tonnes
on a 10‰ gradient track at 60 km/h. He decided to place the firebox behind
the drivers, in order to match the ‘wagon-top’ boiler of peculiar shape and
large firebox with 2100 mm drivers. For that purpose, he reverted the 2-3-1
axle arrangement (then widely used in the USA and known there as Pacific). Rear truck, with two idle axles, could
support the weight of the large firebox without excessive axle load. This
arrangement, later named Adriatic, was never used again in a tender
locomotive; it was featured in five tank engines, rebuilt in Czechoslovakia
from class 354.0, ex kkStB class 229, in
1936 and re-classed 353.1, and in two DB class 66 tank engines of
1950. Experiments with two rear idle
axles, however, continued in some countries for quite a long time. Specific
boiler shape, large drivers and axle arrangement combined to give a unique
silhouette. Even today, many railway fans (including myself) consider this
machine one of the most beautiful steam locomotives ever built – an almost
perfect blend of grace and power – while other (few!) describe it as simply
awkward. De gustibus non est
disputandum... New
locomotive, in line with Gölsdorf’s preference for
compounds, was fitted with a four-cylinder compound steam engine. It went
into production for kkStB as class 210 in
1908. Gölsdorf did not decide to introduce steam
superheating, as he was afraid that high-grade lube oil, necessary for
lubrication with high steam temperature, would be in short supply in
Austria-Hungary. Steam dryer of the Gölsdorf-Clench
type was installed in the smoke box, but this layout did not prove
satisfactory and, in the end, advantages of reheat prevailed. Only eleven
class 210 machines had been built, six by WLF and five by BMMF
– the latter factory is also known as PČM, this abbreviation being
derived from its Czech name – before production switched in 1911 to class 310
with steam superheating. During
WWI, two captured engines (210.01 and 210.10) briefly served in Ukraine and
then were taken over by the Russians. Later they were transferred to the Vladikavkaz
Railway, but their final fate is unknown; nor are their Soviet service
designations, although some sources report that they were assigned. The
remaining nine survived in the kkStB service
until 1918 and then went to PKP
(five were initially transferred to ČSD, but saw little service in
Czechoslovakia, if any). Classed Pn11, they remained in service in
southern and later eastern Poland until 1939. Later, during overhauls, they
were modified and fitted with steam superheaters,
but it is not clear if this was completed before WWII. Although they became
similar to class Pn12 (ex-kkStB 310),
their designation remained unchanged. In
1939 three examples (Pn11-2, -6 and -9) were captured by Germans and
re-numbered 16 051 through 053. They were used mainly in Austria. The rest
fell into Soviet hands, but all except two became German booty after Fall
Barbarossa. Pn11-4 (ex 210.05, WLF 1929/1910) was converted to the
1524 mm track, but retained its Polish service number, albeit written in
Russian script; Pn11-1 was probably not re-gauged. Their final fate is not
known. German ex-Pn11s were returned after the war. Four came from
Czechoslovakia and one from Austria between 1947 and 1948: neither ÖBB
nor ČSD had assigned them any service number. They were given new PKP
numbers, but saw no service; all were written off in 1950. Pn11-8 (ex 210.09,
BMMF 358/1910), returned by DR in 1955, was scrapped without
being entered into the PKP rosters. Moreover, six Pn12s returned after
the war were initially erroneously designated Pn11-7 through 12. Class 210 was certainly among the best and most advanced European express locomotives running on saturated steam, but appeared when superheating had already proven its advantages and had become a well-established design feature. In fact they served as a starting point for Gölsdorf’s most famous brainchild, class 310. No engine of this type has survived until today. Main technical data
1)
After WWII,
including one not restored in service (no number assigned).
2)
Some sources
give 2140 mm – probably due to different standards used by KkStB.
3)
Data on heating
surfaces have been taken from KT vol.1; data from other sources differ
slightly.
List of vehicles can be found here.
References
and acknowledgments
-
Monographic article by Paweł
Terczyński (SK vol. 1/2003); - KT vol.
1, EZ vol. 2; -
www.pospichal.net/lokstatistik
(website by Josef Pospichal). |
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