The Saxon Class XV
T
was a class of goods train steam locomotive operated by the
Royal Saxon State Railways
The Royal Saxon State Railways (german: Königlich Sächsische Staatseisenbahnen) were the state-owned railways operating in the Kingdom of Saxony from 1869 to 1918. From 1918 until their merger into the Deutsche Reichsbahn the title 'Royal' was ...
, which had been conceived for hauling trains and acting as
banking engines for routes in the
Ore Mountains. In 1925 the
Deutsche Reichsbahn
The ''Deutsche Reichsbahn'', also known as the German National Railway, the German State Railway, German Reich Railway, and the German Imperial Railway, was the German national railway system created after the end of World War I from the regiona ...
grouped them into their DRG Class 79.0.
History
The two locomotives were built in 1916 at the
Sächsischen Maschinenfabrik, formerly Hartmann.
The undercarriage of the locomotives was unusual. Instead of an alternative proposal for a twelve-coupled locomotive with sideways-sliding
Gölsdorf axle
The Gölsdorf axle system is used on railway Gölsdorf locomotives to achieve quiet running and low wear-and-tear when negotiating curves. The axle system comprises a combination of fixed axles and axles that can slide transversely, all within a si ...
s, as was realised a year later in the shape of the
Württemberg K, the Saxon Railways decided on a proposal by their head of the engineering department, Lindner, for a design that was unique in Germany: the Saxon XV HTV was given two, fixed, six-coupled drives. This was mainly because they had doubts about the suitability of the ''Gölsdorf'' system for twelve-couplers. The outside axles were designed as
Klien-Lindner axle
The Klien-Lindner axle (German: ''Klien-Lindner-Hohlachse'') is a special type of hollow driving axle on steam locomotives that enable better curve running due to its ability to slide transversely. It was developed by the German engineers, Ewald ...
s and could be slid sideways by about 37 mm from their centre position. The design of these axles required them to be fixed into an outside
frame
A frame is often a structural system that supports other components of a physical construction and/or steel frame that limits the construction's extent.
Frame and FRAME may also refer to:
Physical objects
In building construction
*Framing (con ...
. In the centre of the locomotive was a double
cylinder
A cylinder (from ) has traditionally been a three-dimensional solid, one of the most basic of curvilinear geometric shapes. In elementary geometry, it is considered a prism with a circle as its base.
A cylinder may also be defined as an infin ...
on each side, each with a high-pressure cylinder for the rear and a low-pressure cylinder for the front drive.
This design with its low stress on the rails, low inherent resistance and simple weight compensation was promising especially as it also avoided the use of cranked
driving axles. Similar thoughts in the USA during the 1930s led to the development of
duplex locomotive
A duplex locomotive is a steam locomotive that divides the driving force on its wheels by using two pairs of cylinders rigidly mounted to a single locomotive frame; it is not an articulated locomotive. The concept was first used in France in 1 ...
s. Because the cylinders of adjacent axles also had 28 mm of side play, the locomotive could negotiate radii of as little as 170 m. Through the special design of the cylinders, the use of crank axles (''Kropfachse'') was avoided. Whilst this design enabled the steam lines between the high- and low-pressure cylinders to be extremely short, long admission and exhaust tubes were necessary.
The XV HTV soon proved to be expensive to maintain, particularly with regard to the drives and the hollow axles; as a result no more were procured. Even the usual tendency of all compound engines to sway could not be eliminated by the Klien-Lindner configuration. Wear and tear on the wheel tyres changed the crank settings of the driving gear. That meant that the synchronisation of the drive had to be constantly adjusted, in order to ensure a balanced distribution of effort.
Nevertheless, the engines were successful in practice. They had impressive riding qualities right up to their top speed and wear and tear on the wheel flanges was low. The
Deutsche Reichsbahn
The ''Deutsche Reichsbahn'', also known as the German National Railway, the German State Railway, German Reich Railway, and the German Imperial Railway, was the German national railway system created after the end of World War I from the regiona ...
took both locomotives over as 79 001 and 79 002, but retired them by 1932.
The serial number 79 001 was allocated from 1938 to 1947 to
BLE No. 44 of the former
Brunswick State Railway Company and from 1951 it was given to the former French locomotive,
1-242.TA.602, which ended up in German hands after
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing ...
.
Design features
The
boiler
A boiler is a closed vessel in which fluid (generally water) is heated. The fluid does not necessarily boil. The heated or vaporized fluid exits the boiler for use in various processes or heating applications, including water heating, centr ...
barrel comprised 2 shells with a diameter of 1,450 mm. On the top were two
steam domes which were connected by a pipe inside the boiler. Between steam dome and chimney was a sand box. The
firebox
Firebox may refer to:
*Firebox (steam engine), the area where the fuel is burned in a steam engine
*Firebox (architecture), the part of a fireplace where fuel is combusted
*Firebox Records
Firebox Records was a Finnish record label based in S ...
was made of copper and position over the first axle of the rear drive. The
smokebox
A smokebox is one of the major basic parts of a steam locomotive exhaust system. Smoke and hot gases pass from the firebox through tubes where they pass heat to the surrounding water in the boiler. The smoke then enters the smokebox, and is e ...
superheater was of the ''Schmidt'' type.
The
locomotive frame
A locomotive frame is the structure that forms the backbone of the railway locomotive, giving it strength and supporting the superstructure elements such as a cab, boiler or bodywork. The vast majority of locomotives have had a frame structure o ...
comprised an inside frame of 28 mm thick plate, and an outside frame for the hollow axles of 20 mm thick plate.
The four-cylinder
compound cylinders were arranged horizontally on the outside and each drove its centre axle
See also
*
Royal Saxon State Railways
The Royal Saxon State Railways (german: Königlich Sächsische Staatseisenbahnen) were the state-owned railways operating in the Kingdom of Saxony from 1869 to 1918. From 1918 until their merger into the Deutsche Reichsbahn the title 'Royal' was ...
*
List of Saxon locomotives and railbuses
Sources
*
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External links
Photo
{{DEFAULTSORT:Saxon 15 HTV
0-6-6-0 locomotives
15 HTV
Sächsische Maschinenfabrik locomotives
Railway locomotives introduced in 1916
Standard gauge locomotives of Germany
CC h4vt locomotives
Duplex locomotives
Freight locomotives