Ot1
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Ot1-18 (ex 41 316, MBAG
13275/1940), photographed near Jelenia Góra,
date unknown. Written off in April 1970. Photo by Frank Engel (www.frank-engel.de)
– thanks for permission!
DR class 41 side drawing by K.-E. Hertam (TB vol.1).
Development of the BR41: TCDD 46059, photographed at the Çamlık museum on
DRG 41 182, Orenstein & Koppel 13174/1938. Photo from my collection.
This engine after WWII served with DR,
later was re-designated 41 1182-9 and withdrawn in September 1986.
DR 41 1123-3 (formerly 41 123, BMAG 11062/1938), photographed in
Magdeburg, Germany, on March 29, 1972. Photo by W. Kleiber (postcard from my
collection). This engine was fitted with the modified boiler in 1959 and
survived in service until 1983.
German soldiers posing in front of the 41 010 (Henschel
24312/1938), February 1941, location unknown. This engine remained with DB
after the war; re-numbered 041 010-0, it was withdrawn in March 1968. Photo
from my collection.
DB 41 360 (Jung 9318/1940) was re-boilered in 1958 and remained in use until May 1977. Sold
to a private owner, it sometimes runs with DB special trains. Photo taken in Oberhausen on July 9, 2011, by
someone who wants to be known as ‘Tenderlok’ (nice
name!). Source: www.commons.wikimedia.org.
DR ‘Reko’ 41 1130 (ex DRG
41 130, BMAG 11069/1938), Saalfeld, May 14, 1971. Withdrawn in April 1987. Photo
from my collection.
Another picture from Saalfeld: an
unidentified BR41 in its original version (possibly withdrawn), date unknown.
Photo from my collection.
‘Reko’ 41 150, DR (Schichau
3356/1938), Dessau, date unknown. Photo by H. Müller (from my
collection). This engine was withdrawn in June 1993 and transferred to Bayerisches Eisenbahnmuseum,
Nördlingen.
Yet another ‘Reko’ engine: 41 1180, DR (ex DRG 41 180,
Orenstein & Koppel 13172/1938),
photographed near Leuchtenburg, date unknown. This locomotive
was withdrawn in November 1987. Photo by G. Feuereisen
(postcard from my collection).
41 025, DRG (Henschel
24327/1938), RAW Frankfurt-Nied, 1939. After WWII with DR, transferred to Dampflokmuseum Hermeskeil in December 1991. Source: www.commons.wikimedia.org.
‘Reko’ 042 097, DB (ex 41 097, Krupp
191/1938), fitted with welded boiler and oil firing; Emden depot, date
unknown. Withdrawn in December 1976. Photo by Hugh Llewellyn (source: as
above). |
German
class 41 locomotive was designed in 1934 to fulfill the demand for a fast
freight machine, capable of maintaining relatively high speed while not
exceeding maximum axle load of 18 tonnes. It was
intended to succeed DRG class 5620-29 (ex-Prussian G82,
after 1945 PKP class Tr6). Four
designs with the 1-4-0 axle arrangement were submitted to this specification
by Henschel,
Schwartzkopff,
Schichau
and Krauss-Maffei,
but none of them found favor. It was found impossible to maintain moderate
axle load with a sufficiently large (and heavy) boiler. The choice thus fell on
a 1-4-1 engie, designed by Schwartzkopff
– partly because it utilized the same boiler as the class 03 express
locomotive then in production. This very type was standarized
as BR (Baureihe, or class) 41, however, with
boiler pressure increased from 16 to 20 bar.
This demanded new materials and St47K steel was widely used. Soon it
turned out that this steel was prone to premature ageing and after few years
boiler pressure had to be reduced to 16 bar – the same was the case with
several other types then in use with DRG. It should be noted here that
experiments with even higher boiler pressure, then actively pursued in
Germany, in general proved unsuccessful. Class
41 featured drivers of untypical diameter – 1600 mm, larger than adopted in
Germany for freight locomotives (1400 mm) but smaller than that of typical
passenger machines (1750 mm). Furthermore, maximum axle load could be
increased from 17.6 to 19.7 tonnes by simply
repositioning bolts in levers connecting idle axes with driven axles. These
features contributed to versatility: the machine could be used for fast
freight trains as well as for passenger and even express ones, the more so
that front Krauss-Helmholtz bogie facilitated easy running even at 100 km/h. Two
prototypes were built in 1936 and series production started in 1938 to last
until June 1941, when war needs dictated shifting to more versatile
locomotives of simplified design. Production machines differed from
prototypes in some details, mainly concerning boiler accessories. In all, 366
examples were built by nine companies: Borsig
(73), Esslingen (35), Henschel (86), Jung
(40), Krauss-Maffei (18), Krupp (31),
MBA – formerly Orenstein & Koppel (21), Schichau
(37) and Schwartzkopff (25). Orders
for further 24 machines from Schichau and 46
from Schwartzkopff were cancelled in 1941.
Very soon these locomotives acquired a somehow contemptuous nickname of ‘Oschenlok’ (literally ‘ox loco’), as they were widely
used with express freight trains transporting livestock. In
1937, Turkish state railways TCDD
ordered from Henschel
eleven engines, derived from BR41, for fast passenger trains. These
locomotives were slightly lighter and had modified boilers with larger superheaters; diameter of drivers was increased to 1750
mm and cylinder bore to 650 mm. Designated No.46051 through 46061, they
served mainly at the Istanbul-Ankara line. No.46059 (Henschel 23659/1937) has been preserved at the steam locomotive museum in
Çamlık. After
WWII most class 41 machines remained in Germany. 220 examples served with DB
and DR had 119. One engine, 41 153, was taken over by
Czechoslovak railways, but probably was not allocated a service number; in March
1955 it was transferred to an industrial operator. Soviets took six machines,
but nothing is known about their further service. PKP took over 19
locomotives of this class (some sources give 18 – probably because the last
one was accepted as late as in 1948). One more (41 076, Borsig
14797/1939) was handed over by DR in 1946, but this engine was not
restored in service and had no PKP number. It was soon handed over to MPS (Soviet ministry of transport) and
withdrawn in November 1948. According to the monographic article by Ryszard Stankiewicz (see
References), seven examples were overhauled in Bydgoszcz in 1946 and saw
brief service with PKP, which is
not confirmed by www.beitraege.lokomotive.de.
They retained their original DRG
service numbers and in late 1946 were handed over to Soviet military railways,
finally ending up with DR (one) and
DB (six). Contrary to pre-war DRG
practice, Polish locomotives of this type were used almost exclusively with
passenger trains, hence their designation Ot1. Just as with those operated by
DR and DB after WWII, boiler pressure was soon reduced to 16
bar, although some tests with higher pressure were in fact performed. Most
Ot1s were used in Lower Silesia, but as electrification progressed, many of
them were shifted to Lublin, to replace elderly and never entirely
satisfactory Os24s. In early 1950s six examples were briefly based in Iłowo. Premature
ageing of boiler elements was an inherent flaw of these otherwise successful
machines, therefore reconstruction was the only means to keep them in
service. In Western Germany, 103 machines were fitted between 1957 and 1961
with new welded boilers of high efficiency, which radically changed their
silhouettes. Forty of them were converted to oil firing and re-designated
class 042; last of them was withdrawn in October 1977. Last original machines
(not reconstructed – class 041) were written off in 1971. In Eastern Germany,
21 machines were fitted with reconstructed welded boilers (otherwise
identical with the original ones) and, from 1961 onwards, eighty were rebuilt
with entirely new boilers of indigenous design. Last DR machines
survived in service until 1984. PKP had only nineteen Ot1s, so
launching a dedicated reconstruction program was perhaps considered
unjustified. Thus, when signs of intensified deterioration of material
properties had been discovered during major overhauls in late 1960s, this
meant a death sentence. All machines of this class were written off between
August 1969 and March 1973; the last of them was Ot1-17 (ex DRG 41
313, Orenstein & Koppel
13272/1940). This meant that, in effect, these modern and efficient
locomotives were outlived in service by older classes. Unfortunately, no
Polish Ot1 has been preserved (nothing particularly shocking for a railway
fan in Poland!). In contrast, as many as 23 machines of this type (most of
them, if not all, in reconstructed versions) have survived in Germany. None
of them, however, is fitted with original Wagner-type smoke lifters, which
have been replaced by narrow Witte-type ones. Four of them (41 018,
41 144, 41 231 and 41 360) are in working order and there are
plans to restore further two in service. 41 105 (Krupp 1927/1938) has had an eventful career: after 31 years with DB
it was sold in 1976 to The Netherlands and served as a stationary boiler in
Vlissingen until 1979. Sold to Stoom Stichting Nederland, Rotterdam, it was restored in
service in 1980 and ran with special trains until 1991, when boiler ticket
expired. There are plans to bring it back to the working order. Main technical data
1)
Some sources give 18 – probably because Ot1-19 was
accepted later than other examples; one more not restored in service. 2)
Initially 2.04 MPa, later reduced. 3)
1000 / 1000 mm for locomotives built by Borsig. 4)
Repositioning of undercarriage lever bolts allowed
for reducing weight on drivers to 70 000 kg and maximum axle load to 17.6 T. List of vehicles can be found here. References
and acknowledgments
-
Monographic
article by Paweł Terczyński (SK vol.
2/2001); -
Monographic article by Ryszard
Stankiewicz (SS
vols. 151 and 152); -
TB
vol. 1; -
http://www-personal.umich.edu/~khmiska
(website by Kurt H. Miska – unfortunately currently
not active); www.beitraege.lokomotive.de
(locomotive database by Ingo Hütter). |
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