SŽD series Т
| SŽD series Т | |
|---|---|
 T a
|
|
| Numbering: | T a : 10,000-10,004 T b : 10,005-10,009 |
| Number: | T a : 5 T b : 5 |
| Manufacturer: | T a : ALCO T b : Baldwin |
| Year of construction (s): | 1931 |
| Retirement: | Late 1950s |
| Axis formula : | T a : 1'E2 'h2 T b : 1'E1' h2 |
| Gauge : | 1524 mm |
| Length: | T a : 16,655 mm T b : 15,675 mm |
| Service mass: | T a : 168 t T b : 152 t |
| Friction mass: | 115 t |
| Wheel set mass : | 23 t |
| Top speed: | 65 km / h |
| Indexed performance : | -1,400 hp |
| Starting tractive effort: | without booster : 240 kN - 250 kN with booster : 300 kN |
| Driving wheel diameter: | 1,524 mm |
| Impeller diameter front: | 914 mm |
| Rear wheel diameter: | 1,070 mm |
| Control type : | Walschaerts |
| Number of cylinders: | 2 |
| Cylinder diameter: | 700 mm |
| Piston stroke: | 760 mm |
| Boiler overpressure: | T a : 17 bar T b : 14 bar |
| Number of heating pipes: | T a : 56 T b : 35 |
| Number of smoke tubes: | T a : 176 T b : 166 |
| Grate area: | T a : 8 m², T b : 7.34 m² |
| Superheater area : | T a : 160 m² T b : 150 m² |
| Evaporation heating surface: | T a : 380 m² T b : 340 m² |
The steam locomotives of the SŽD series Т were test locomotives with an increased axle load of 23 t, which were manufactured in 1931 by the North American plants ALCO ( T a ) and Baldwin ( T b ) in five copies each and were in use until around 1956. They can be described as the development vehicle and forerunner of the SŽD series ФД , which appeared in larger numbers from 1931 .
history
Precondition for the appearance of the steam locomotive
Around 1930 there was a great increase in freight traffic on the railways of the former USSR . The steam locomotive series Э , which at that time was the dominant freight locomotive in the USSR, was no longer able to meet the demand for heavier and faster freight trains with their friction mass of 80 t and their speed. This created the need for more powerful, faster and more powerful steam locomotives.
Various groups of experts from the Ministry of Railways (NKPS) were working on different approaches to solving this problem. One group offered to increase the number of coupled axles to seven to eight in order to increase the friction mass of the locomotives. This made it possible to maintain the axle pressure of 20 t, which meant that the superstructure did not have to be reinforced . Prototypes for locomotives of this direction were the SŽD series АА 20 , the only steam locomotive in the world with seven coupled axles in a fixed frame, and the SŽD series Я with eight powered axles based on the Garratt design . Both prototypes remained individual pieces because, on the one hand, the buildings and turntables in the depots had to be significantly enlarged for their operation . In addition, the single-frame locomotive caused great difficulties entering the curved track.
Another group of experts offered locomotives with five coupled axles with an increase in axle pressure to 23 t (later 27 t). Assuming that these locomotives should run on rails of profile IIa (load per meter 38.4 kg), the bedding of the superstructure had to be converted to ballast bedding and the number of sleepers increased. These experts were guided by experience from North America , where steam locomotives were operated with an axle pressure of up to 32 t.
Design and manufacture of steam locomotives
Even at the beginning of the attempt to realize the project, the designers encountered a difficult task - not one of the Soviet steam locomotive works had experience in the construction of steam locomotives with an axle pressure greater than 18 t. The frame was the biggest obstacle to development. Preliminary calculations showed that a sheet metal frame, which was used on all steam locomotives of the former USSR at the time , could not withstand this axle pressure. This required the transition to frames with a bar construction, which was widespread on the railways of North America at the time. In the former USSR, there was no experience with this type of frame. It was decided to order a small series of test locomotives from American companies, and after their testing, an analog production of locomotives of the same dimensions in the form of the SŽD series ФД should take place. A similar situation was repeated later with the construction of electric locomotives in the form of the C series as a prototype or the С С series as a replica or with the construction of diesel locomotives in the form of the SŽD series Да as a prototype or the SŽD series ТЭ1 as Replica.
In 1930 the Ministry of Railways (NKPS) ordered five steam locomotives each with an axle pressure of 23 t from the American companies ALCO ( T a ) and Baldwin ( T b ). In October 1931 the ordered steam locomotives T a with the numbers 10,000 - 10,004 and T b (numbers 10,005 - 10,009) arrived at the Leningrad steam locomotive repair shop .
Construction of the steam locomotives
The steam locomotives had a bar frame with beams made of vanadium steel with a thickness of 140 mm. The drive wheels had a diameter of 1520 mm and were designed as spoked wheels . Differences between the two production variants of the locomotives resulted from the wheel arrangement; the T a had two trailing axes, the T b only one. Since both constructions had the same axle pressure, the different total weight resulted largely from the different number of smoke and heating pipes. The steam locomotive's fire box was of the radial type, the boiler was equipped with an Elesko E type superheater . A surface preheater was arranged in front of the smoke chamber at T a , but this was missing from T b . A booster was set up for the tender . It also had a mechanical grate loading system based on the standard stoker system .
The design speed of the steam locomotive was 85 km / h.
Fate of the steam locomotives
In 1931 both steam locomotive designs were given the then Stalin Railway . In the course of their inspection, a tensile force of 240 - 250 kN (and 300 kN with the booster included ) was determined. Since the axle pressure on the locomotives was up to 12% higher than the permissible value, despite their enormous pulling power, there was no great acceptance in the operating service. Perhaps it was also due to the fact that only ten locomotives were manufactured, while the SŽD series ФД , which was produced in large numbers, could be used more freely. Therefore, the locomotives were gradually removed from train service. At the beginning of 1956 they were still part of the locomotive park.