Helper engines then in use had become
almost totally inadequate. The Königlich Bayerische Staatsbahn; Bavarian
State Railways (K.Bay.Sts.B.) (From here on I will use the
abbreviation to save valuable space, author.) thought a tank engine
with five driven axles (5/5), an E-Kupler (E-coupler)in German with
16-ton axle loading would be the solution. But, it was not enough. The
next idea was to make this a six-axle tank engine with 16 ton axle
loading. Again, a lack of experience with this type of locomotive and
the anticipated abrasion of wheels and rails led to discarding this
approach.
J.A. Maffei’s director of engineering Anton
Hammel suggested a 2x3/3 or 2x4/4 Mallet, a suggestion acceptable to the
K.Bay.Sts.B. Little time was lost in starting to design the much needed
helper engine. Anton Hammel had some very specific suggestions for the
dimensions of the cylinders, firebox, wheel size, etc. It was to be a
2x4/4 design.
By September 1913 the prototype, shop
number 3414, was delivered to the K.Bay.Sts.B. with road number 5751
ready for initial testing at Maffei’s Munich facilities. While tests in
the Munich region could not duplicate the conditions prevailing in the
three regions outlined, the results, nevertheless, proved very
encouraging.
With completion of the new machine’s
breaking in period and the railroad personnel’s familiarization with the
engine, official testing began on April 9, 1914. The K.Bay.Sts.B.
ordered a total of 15 of the new Mallet designated Gt 2x4/4 (D’D h4v) -
D’ = four axles in a pivoting frame; D= four axles in a fixed frame; h =
superheated steam; 4 = the number of cylinders and h = compound
locomotive) from Maffei in Munich and all were delivered in 1913 and
1914. Their shop (factory) numbers ran sequentially from 3414 to 3428
and the railroad numbered them 5751 to 5765. When the Deutsche
Reichsbahn was formed in the 1920s, the engines became BR 96s and were
numbered 96 001 to 96 015. The first 10 engines were assigned to
Rothenkirchen and the remainder to Aschaffenburg.
Here’s what the trade press had to say abut
the new Bavarian Mallet. From Die Lokomotive in 1914…"Now this
largest and most powerful European steam locomotive being put into
service by the Bavarian State Railways is a clear indication of Maffei’s
expertise in developing the Mallet articulated locomotive. It is far
superior to the various helper locomotives it replaces."
From the British magazine The
Locomotive, also in 1914…"Some new banking (helper) locomotives put
into service by the Bavarian State Railways are the heaviest and most
powerful tank engines in Europe." The editor went on to point out that
while American adoption of the Mallet design resulted in larger
machines, the original Mallet is very much an "Old World" invention.
Using a train of 1,000 tons over the
Lichtenfels to Rothenkirchen line (23 miles), the previous running time
of 103 minutes was reduced to 68 minutes. The next grade from
Rothenkirchen to Steinbach was done with a 410 ton train using only a
single Gt 2x4/4 in a record 29 minutes compared with the previous time
of 58 minutes. Other similar tests were equally successful.
Extrapolating these and other savings, the railroad anticipated annual
cost savings of DM 100,000, (roughly $25,000) a not inconsequential
amount in those days.
Similarly satisfying results were realized
on grades in Northern Bavaria. The 3.2 mile 1:20 grade between Laufach
and Hergenbrücken had a great deal of passenger and freight traffic.
Despite the advantages gained by using the new locomotive, some of the
gains were negated by the machine’s complexity. Maintenance costs were
definitely higher.
Still, this engine, the largest and
heaviest articulated locomotive in Europe, had proven itself to the
point where the K.Bay.Sts.B. ordered an additional ten from Maffei in
1922. They were not completely identical to the first lot. They were
shop numbers 5336 to 5345; KBStB 5766 to 5775 and then DR 96 016 to 96
025.
Vigorous daily use revealed the need for
some modifications and the newer machines, those delivered in 1922/1923,
were actually modified first. The 1913/1914 engines were updated between
1929 and 1932.
Service
Use of the Gt 2x4/4 was confined to
relatively few locations. The first and second lot were split up between
Rothenkirchen for the Steinbach-am-Wald 1:40 grade and Aschaffenburg for
the Schwarzkopf Tunnel near Heigenbrücken 1:50 grade. Assignment to the
Schiefe Ebene, the third steep grade, did not take place until 1935 in
conjunction with building of the Munich-Berlin Autobahn. Here the
massive Mallet helped move heavy freight trains hauling thousands of
tons of earth and rocks resulting from the Autobahn construction.
Some Gt 2 x 4/4s were pressed into helper
service in Belgium during World War 1. Some were assigned to work as
helpers as well as in conventional service in Brügge, Westphalia from
1929 to 1933. Others were scattered throughout regions of Germany that
required some helper service or the use of a heavy freight locomotive.
They were also tried on the famous Geislinger Steige but not put into
service there because the BR 95 (Prussian T20) proved equal to the task.
Also, there simply were not sufficient Mallets available in the 1930s
and 40s. The rugged Mallets could also be seen in Landshut, Regensburg,
Hof and Munich Main Station in the 30s and 40s. They survived the second
World War in generally good order but by 1947 the last of the 96s were
taken out of service in West Germany. The very last ones to be placed
into service were two in 1944 on the Halberstadt – Blankenburger
Eisenbahn in Germany’s Harz region. They then served in East Germany
Deutsche Reischbahn until 1949. Then for another five years they were
used as steam generators.
A measure of the engine’s well thought out
design was that the second order (1922/23) was, for all practical
purposes, configured identically to the first lot. With the formation of
the Deutsche Reichsbahn Gesellschaft (DRG) came an increased emphasis on
better maintainability and less complexity as seen in the Gt 2x4/4. The
ascendancy of the BR 95 (Prussian T20) made that abundantly clear.
By October 1954, the last of the BR 96s (96
002 and 024) were scrapped. There had been some hope that 96 006 might
survive and be installed in a museum but, alas, that was not to be.
Alas, there are no survivors. There are, however, two magnificent models
of the BR 96. A 1:10 scale model of engine 96 016 was built in 1939 by
machinists in training at the RAW Ingolstadt shops. This model is now in
the Deutsche Museum in Munich. Earlier, in 1935, the same shop built a
1:10 replica of 96 025, which is now in the Nürnberg Transportation
Museum.
Original and modified machines
The Gt 2x4/4 (D’D h4v) was a four cylinder
0-8-8-0 standard gauge articulated locomotive designed primarily for
helper service in the Bavarian region of Germany. Unquestionably, it was
a very complex locomotive for its time and the engineering staff at
Maffei had all it could do to solve the many problems inherent with
designing and manufacturing the many steam and water lines with the
necessary flexible couplings needed for a Mallet design. The smallest
radius curve it could negotiate was 590 ft. Maximum speed was 31 mph.
The locomotive had two sets of four-axle drivers. The high pressure
cylinder serves the rear (nearest to the cab) drivers and the large,
canted low pressure cylinder powers the front set of drivers. The
diameter of the high pressure cylinders measured 20.4 in. which was
increased to 23.6 in. during modification. The low pressure cylinders
were 31.5 in. in diameter, a measurement that remained unchanged when
the engines were modified. Heusinger valve gear was used.
Both frames of the engine were welded 1.2
in. rolled plate steel. A hinge pin of 5.9 in. diameter couples both
frames. Each four-axle section has a wheelbase of 14.76 ft, or 4.92 ft
between axles. The total wheelbase is 40 ft. Empty weight for the first
15 locomotives was 99.4 tons, which remained at that figure upon
completion of the modification program. On the other hand, the second
series started out at 101.7 tons and gained during modification to weigh
in at 105.4 tons.
The boiler is the largest one ever
manufactured by Maffei for the K.Bay.Sts.B. It is mounted on the rear
frame of the articulated frame. The inside diameter of the boiler is 5.8
ft of material that is just short of ¾ in. in thickness. The highest
point on the boiler is 9.67 ft above the top of the rails. Sand domes
supplied traction sand to the fronts and rears of each of the drivers.
The pipes leading from the sand dome supplying the front set of drives
use flexible couplings to accommodate the movement of the boiler in
relation to the drivers.
The coal and water capacities for this
rather large locomotive were actually rather small. Of course, these
relatively low capacities were entirely sufficient since the BR 96 was
used almost exclusively in helper service. The first series of engines’
coal capacity was 4.0 tons and upon modification, this was increased to
4.5 tons. Water capacity was not changed and was 388 ft3.
Initial coal capacity of second series was 4.5 tons which became 5.0
tons during modification. Water capacity remained unchanged at 434 ft3.
Since the Gt 2x4/4 spent as much time
traveling reversed and going forward, the engine featured a fully
enclosed cab for greater crew comfort. Additional specifications are
provided in the attached table.
Updating of all BR 96s was carried out in
two stages. The second series (96 016 to 96 025) was the first to be
modified. The process lasted from 1925 to 1927. When the BR 95 (Prussian
T20) entered service in 1923 to begin tests and evaluation with what
turned out to be very favorable results, it became apparent that the
complex Gt 2x4/4, with its high maintenance requirements, needed some
serious rethinking.
Personnel assigned to the Mallet pointed to
the difficulty of effectively applying all of its power to the track.
The design had an inherent tendency to go into sideways oscillations
about its frame pivot point. This resulted from the difference in the
volumes of the high and low pressure cylinders. It required a very
skillful locomotive driver to prevent these potentially dangerous
oscillations from even starting. The net result was that it was never
really possible to utilize all of the steam that the machine’s huge
boiler provided. To find a solution to the problem Maffei engineers set
about checking and redoing some of their cylinder calculations in 1925.
Using engine 5773 (96 023) as a test bed, they installed larger high
pressure cylinders. This lowered the pressure differential between the
high and low pressure cylinders from 1:2.37 to 1:1.78. There was every
indication that this was the answer to the oscillation problem. In the
Bavaria vs. Prussian contest, i.e., Gt 2x4/4 vs. T20, the former clearly
emerged as the winner. The DRG reacted quickly and requested that Maffei
carry out the same modifications on the remaining Mallets of the second
lot. The cost per engine came to DM 59,100 or approximately $15,000.
The modifications to the cylinders were not
the only ones. There is not enough space in this article to enumerate
all the changes in detail. Updates included boilers, fire gratings, ash
containers, the feedwater pump and preheating system, sand domes and
frames.
Modifications of the locomotives of the
original 1913/1914 series (96 001 to 96 015) were started on 96 003 and
005 in August 1929 at RAW (Reichsbahn Ausbesserungserk; modification
center) Ingolstadt near Munich. Not modified in numerical sequence,
96 012 was the last machine to be serviced
thus. The date was December 2, 1932. Modifications and updates included
new boilers and a new retardation braking systems which were removed by
the end of the 1930s. The complex Riggenbach retardation brake was a
waste of time according to Josef Eich, an engine driver. He said, "by
the time everything was adjusted and set, we were back on level track.
According to a comment made by Maffei
executive Baron Ludwig von Welser, "The success of the modification
program met all expectations and, as a result, the performance of the Gt
2x4/4 is such that it does not have to fear competition from the
Prussian T16 and T20."
Specifications
Editor’s note – Without Clinton Ross’ generous loan of
the book "Die Baureihe 96 – Malletriese für den Schiebedienst" this
article would not have been possible. It is also not possible to impart
all of what is contained in this 275 page volume.
This article should be considered a brief introduction to
what is a very fascinating locomotive.
Sources
"Die Baureihe 96 – Malletriese für den Schiebedienst," Steffen
Lüdecke, EK Verlag, ISBN 3-88255-831-8, 1991.
"Die Super Baureihe 96", Märklin Magazin, 5/94, p. 50.
"Bayerische Kolosse"; Eisenbahn Magazin, 3/94, p. 30.
Weisbrod, Bäzold, Obermayer, "Das Grosse Typenbuch Deutscher
Lokomotiven," ISBN 3-334-70751-5, 1995, p. 180.
Königlich Bayerische Staatsbahn (K.Bay.Sts.B.); Bavarian State
Railways
Disposition of BR 96 Locomotives
Editor’s note: there is far more information on the
disposition of these machines than can possibly be included in this
article. Readers fortunate enough to have access to "Die Baureihe 96 –
Malletriese für den Schiebedienst," by Steffen Lüdecke can find more
information there.
96 001 - Left Bavaria in 1929 for Sauerland where it helped on
the 4 mile (6.4 km) Brügge – Lüdenscheid line with its 28% grade. The
engine was removed from service in 1933 and phased out in 1936.
96 002 - Together with 96-024 assigned to
Halberstadt-Blankenburger Eisenbahn (HBE) in 1944 to help move heavy
limestone trains on the 19 mile (30.5 km) Rübelandbahn in the East Hartz
region. Almost deliberately scuttled on April 17, '45 in an attempt to
halt the U.S. troops' advance in the Hartz region of Germany. Ended its
career doing heavy switching in Stendal. Mustered out in 1954.
96 003 - Left Bavaria in 1929 for Sauerland where it helped on
the 4 mile (6.4 km) Brügge – Lüdenscheid with its 2.8% grade. The engine
was removed from service in 1933 and phased out in 1936.
96-004 -
96-005 - Left Bavaria in 1929 for Sauerland where it helped on
the 4 mile (6.4 km) Brügge – Lüdenscheid line with its 28% grade. The
engine was removed from service in 1933 and phased out in 1936.
96-006 - Until 1952 reserved for Nürnberg Museum but scrapped
before installation. Indirectly
96-007 - Ended its career as a heater engine.
96-015 - destroyed in World War 2.
96-016 - First engine of 2nd order.
96-024 - Together with 96-002 assigned to
Halberstadt-Blankenburger Eisenbahn (HBE) in 1944 to help move heavy
limestone trains on the 19 mile (30.5 km) Rübelandbahn in the East Harz
region. Ended its career doing heavy switching in Stendal. Mustered out
in 1954.
96-025 – Last BR 96