Tender
A tender is a storage wagon that carries the fuel and water for steam generation from steam locomotives . It is because of this not necessarily required component tank locomotives themselves are fitted for shorter routes with storage bunkers. The tender is coupled directly to the locomotive, mostly at the rear end with a fire box and driver's cab so that it can be "towed" by the locomotive during normal operation.
The development of battery - charged so - called “e-tenders” for electric locomotives has been planned since 2012 in order to be able to overcome non-electrified sections of the route.
execution
Depending on the design, hard coal , lignite , coal dust , wood , peat , light heating oil or heavy oil can be carried as fuel . The bunker space for the fuels is usually specially designed for the respective type of fuel. Since the possibilities for renewed water supply have become rare on today's historic steam train journeys, two tenders are often run behind the locomotive to increase the water supply. Operation with additional water tenders (often simple tank wagons ) was also common in arid areas, for example in South Africa .
The size of a tender depends on the operational requirements (length of the route, supply stations, time required for supply). Tenders used in Germany held between 5 and 40 m³ water and 4 to 18 t fuel; in the US it was up to 94.6 m³ of water and 26.5 t fuel is common. Where water could be taken from troughs during the journey , less space was planned for the water supply and more fuel was carried with you (global maximum: 41.7 t coal in the NYC's Niagara tender , plus 68.1 m³ water).
Because of the large mass with full supplies, the comparatively short tenders usually have many wheels arranged in quick succession . The construction with two two-axle bogies is very common . Six to eight-axle tenders were common on the large US locomotives. Due to its high mass, the twitching (bumping) of the locomotive is reduced during operation.
Special forms
Condensing tender
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For railway lines with poor supply, for example in the Second World War for railway lines in the German-occupied areas of the Soviet Union (see: Class 52 ) and for extremely arid lines in South Africa ( SAR class 25 ), condensation locomotives with a condenser tender with external cooling fins were built recovered the water from the steam from the locomotive. A condensation tender is an exhibit in the German Steam Locomotive Museum in Neuenmarkt-Wirsberg .
Corridor tender
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British express locomotives were equipped for long-distance non-stop journeys with tenders that had a side aisle for changing personnel. The Prussian S9 Altona 561 , type Wittfeld-Kuhn, had such a gear.
Rigid frame tender
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Rigid frame tenders are bogie-less tenders with four or more axles mounted in the frame. They can be built much lighter than bogie tenders with comparable supplies, but with poorer running properties. For reasons of mass, rigid frame tenders were more common in Austria than bogie tenders. The first of this type were the tenders of the Südbahn- 570 in 1915, later referred to by the BBÖ as SB tender series 87. All other tender series were then of this type.
The only bogie tenders in Austria remained the series 86 built from 1902 to 1916 , which were mainly coupled with the express train locomotives of the KkStB series 310 , and the special type of series 88 from 1916 with internally mounted wheelsets; an attempt to reduce the empty mass. After the First World War, further rigid frame tenders were developed and built in Austria. The tenders of the BBÖ tender series 84 were coupled with the locomotives of the 214 series and the BBÖ tender series 85 with the 2'D express train locomotives of the 113 series. A bogie tender of the 86 series held 6 tons less coal than a rigid frame tender of the 85 series for comparison. The Floridsdorfer rigid frame tender for the DR series 52 is a further development of the much lighter tender construction of the Austrian railways. These tenders were developed by the Floridsdorf locomotive factory in Vienna and later also built by the Rax works in Wiener Neustadt and the Kaiserslautern iron works. They were coupled with locomotives of the DR class 52 as well as individual copies of the DR class 50 .
Today there is only one rigid frame tender of the DR type K4 T30 in Austria , which has been converted into a fire extinguishing foam vehicle. It is planned to restore this to its original state in order to couple it with the 52.100 in the future. In Germany , this type of tender can still be seen at 52 6666 in the former Berlin-Schöneweide depot .
Vanderbilt tender
In 1901 Cornelius Vanderbilt III patented a tender which, like a tank car, has a cylindrical water container on which the coal box is placed in the front area. The advantages of this design were - for a given volume - a smaller surface area, lower empty weight and greater rigidity, the disadvantage was the greater length, because the water tank makes insufficient use of the vehicle's gauge. Tenders of this design were used by some US railroad companies, for example the Baltimore and Ohio Railroad , as well as the South African Railways (among other things, Class 24 and the last delivery of Class 19D were equipped with it).
Tub tender
During the Second World War, tenders with a simplified design were built in large numbers in Germany, with the water tank being made from sheet metal bent in the shape of a tub, based on the model of the American Vanderbilt tenders and also comparable to self-supporting tank wagons. The advantage of the tub tender lies in its frameless and therefore material-saving design. The disadvantage that tub tenders make insufficient use of the available vehicle gauge is secondary to this . The lower water content and the resulting lower total mass were not relevant for the light series 50 and 52 (approx. 15.2 t wheel set driving mass) and the series 42 (wheel set driving mass approx. 17.6 t), since the maximum wheel set driving mass was already limited by the locomotive and is also reached by the tender with full supplies. In contrast, the tub tenders were only coupled with heavy freight locomotives of the 44 series (wheel set traveling mass 19.3 t) in exceptional cases. German tub tenders run on adapted freight car bogies of the standard design made of pressed sheet metal.
Cabin tender
The cabin tender is a tender design in which a small room has been set up for the freight train attendant / train driver , which saves the freight train escort car. The cabin is located behind the coal box and can be accessed through a door from either side of the tender. By installing the cabin, the supplies of the tender are reduced. Cabin tenders were created at DB from box tenders 2'2 'T26 of the BR 50 and at ÖBB from tub tenders Rh 9593 (formerly DR K2'2' T30), which thus became Rh 9793. These were coupled with locomotives of the 42, 52 and 152 series.
With a length of 2080 mm, a width of 1400 mm and an average height of 2253 mm, the DB cabins were slightly smaller than those of the ÖBB tenders. Two large windows to the rear (with hand-operated windshield wipers) and the two door windows offered a good view. The walls of the cabin were clad with plastic panels, and a work table extended the entire length of the cabin. An upholstered folding seat in front of the table and a swiveling table lamp provided good working conditions for the driver . To the right and left of the table were two emergency folding seats in the swivel area of the doors. Two shelves with sorting compartments, a wash basin, a water jug and four coat hooks completed the equipment. The cabin was heated by underfloor heating and two radiators that were fed by the steam heating line of the locomotive .
At the DB, the Lingen repair shop took over the series production of the tenders in 1958 after experience had been gained with several tenders in test execution (inclined window installation). In August 1962, 735 tenders were finally converted.
Coal dust tender
In order to facilitate the very harsh working conditions of the stokers (in the GDR at the beginning of the 1950s lignite with a low calorific value was fired), the Deutsche Reichsbahn built tenders for some locomotives of the DR series 44 , series 58 and DR series 52 in the tender system from 1952 Wendler (named after the designer and national prize winner Hans Wendler ).
In the Wendler system, the lignite dust in the dust bunkers was conveyed (discharged) to discharge valves using compressed air. In the so-called dust tube, the dust was then mixed with the sucked in combustion air and passed through vortex burners into the fire box . The vacuum required to suck in the dust-air mixture was generated by the reinforced induced draft system (blow pipe with nozzles). The blower was used in normal operation even with the regulator open up to a valve chest pressure of 10 atmospheres.
Since large and cost-intensive coal dust bunkers had to be kept in the railway depots for loading, no further modifications were made in favor of the conversion to the main oil firing system.
Impulsive
Occasionally, common supplies of fuel were equipped with powered axles. In this way, the weight of the supplies was used as additional friction weight . This design was found on some American mallet locomotives of the type_Triplex in the 1930s.
From 1927 to 1937 the Deutsche Reichsbahn used a class 38 machine ( DR T 38 3255 , wheel arrangement 2'C + 1B2 ') with an additional turbine drive on the tender as an experiment.
Triplex XA of Virginian Railways with power set on the tender
DR T38 3255 with additional turbine drive on the tender
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Battery tender ("E-Tender")
Battery Tender were on previous developments of Akkumulatorlokomotiven or - railcar used (eg. BBA B 660 , BBA EL 61 ), to save drive energy on the go and retrieve it when no external power supply to the operating voltage is present or to general to be independent of the corresponding external infrastructure for at least a certain period of time.
The development of “e-tenders” for electric locomotives has been planned since 2012 in order to be able to carry electrical energy stored in batteries : This should enable trains with electric locomotives to travel on non- electrified sections of the route without changing locomotives . This provides for a joint development by the German Aerospace Center (DLR) and Deutsche Bahn .
coupling
A useful side effect of the mostly heavy tender (fully loaded around 50 to 70 tons for European railways and approx. 130 to 205 tons for US railways) is that its weight stabilizes the often restless, jerky running of the steam locomotive, which is the result of the free mass forces of the engine results (especially with two-cylinder locomotives). The tender is therefore connected to the locomotive without play (but not rigidly).
Contrary to the usual method of coupling between the wagons of a train or locomotive and train, the connection between locomotive and tender does not have to be disconnected during operation. The so-called main coupling iron serves as a connecting element that absorbs the tensile forces. This is a massive, rigid rod with a hole at each end. So that the inserted coupling bolts do not tilt when they move obliquely, the holes in the bores are curved inwards in a funnel-shaped manner.
The coupling iron is often permanently under tension from so-called shock buffers that push the locomotive and tender apart. The sliding plates on which the shock buffers stop at the front are also convex or beveled. If the locomotive and tender move sideways against each other, the springs of the buffers are compressed more strongly, which in connection with the inclined contact surfaces leads to a restoring force. The buffers are attached to the tender, the sliding plates to the locomotive.
A break in this coupling would have fatal consequences, as the heater is practically constantly moving over the connection between the two vehicles . In addition to the main coupling iron, German standard locomotives also have two lateral emergency coupling irons which ensure a connection even after the main coupling iron breaks. The bores of the emergency coupling bars are designed as elongated holes in order not to impair the function of the main coupling bar and the bumper.
Since this connection is designed between the locomotive and tender on primary train and the bias voltage in comparison with the train weight is relatively small, Schlepptender locomotives slide coatings with subsequent pushing ahead usually with the smoke chamber. The locomotive drives forward and pushes the wagons in front of it. If they were to push heavy trains with the tender, the train weight would overcome the pretension of the buffer springs and put pressure on the main coupling iron.
Notation
The tenders of German express, passenger and freight locomotives were given the designation "T". In addition, further information was given in digits: wheel alignment and water supplies in cubic meters, the fuel supplies were not given, furthermore information as to whether the tenders correspond to a country design of the German Reich up to 1919.
Examples:
- pr 3 T20 ( Prussian State Railways , three axles mounted in the main frame, 20 m³ water)
- 2'3 T38 (a two-axle bogie and three axles mounted in the main frame, 38 m³ water supply)
- 2'2 'T34 (two two-axle bogies, 34 m³ water supply)
- bay 2'2 'T26.2 ( Royal Bavarian State Railways two two-axle bogies, 26.2 m³ water supply)
In old Austria-Hungary and some of its successor states such as Austria and Czechoslovakia, separate series designations and serial numbers existed for tenders without any recognizable connection with the numbers of the locomotives coupled with them.
In the case of translations from the English language, it should be noted that the German " tender locomotive " in English is a tender locomotive , whereas a "tender locomotive" is translated as a tank locomotive .
See also
- Supporting tender locomotive
- Tender drive (model railway)
Web links
Individual evidence
- ↑ a b Train with battery on board. ( PDF ) In: dlr.de . German Aerospace Center , September 19, 2012, accessed on February 20, 2020 .
- ↑ Hermann Jahn: Freight wagon bogies: pressed sheet metal, welded - "standard design" (with humped upper edge). Technical data for bogies. In: Drehgestelle.de . March 24, 2010, accessed February 20, 2020 .
- ↑ Historical picture of a cabin tender with inclined windows. ( JPEG ) In: dampflokomotivarchiv.de . January 21, 2017, accessed February 20, 2020 .
