TE125

In the mid -1960s the increase in the weight of passenger trains led to the fact that in some non-electrified directions of the road, two-section diesel locomotives 2ТEP60 were forced to use (for example, Uralsk - Saratov - Tambov - Michurinsk). However, often these locomotives did not fully utilize their capabilities, and doubled the towing weight only increased operating costs. Then, in the main locomotive building department of the Ministry of Heavy, Power and Transport Engineering, the development of technical specifications for a main diesel locomotive with a capacity of 4000 hp began with a four-stroke diesel engine and an alternating-direct current electric transmission and with the unified crew of the newly-emerged diesel locomotive TE109 (topic Г68.4.07.011). September 4, 1968, the Deputy Minister of Heavy, Power and Transport Engineering Aismont A. approved the terms of reference for the design of the locomotive. On September 15, 1975, the Deputy Minister of Heavy and Transport Engineering, Matveev E. S., approved the amendment No. 1.

In 1976, the Voroshilovgrad plant presented a technical project, executed in the amount specified in the statement of technical project 2132.00.00.000TP for a diesel locomotive with a capacity of 4000 hp. in a section with a supporting-frame suspension of a TED for export deliveries, with a four-stroke diesel engine of type 2-5D49 and an electric transmission. On June 2, this project was approved by Matveev E. S.

In 1978 (there is evidence that in 1974 ) the plant produced an experimental six-axle passenger diesel locomotive, which was given the full designation TE125-001 . After a run of 500 thousand kilometers and the completion of operational tests in this way, the locomotive was handed over to the All-Union Scientific Research Institute of Railway Transport for bench testing.

Despite the unification (body, powerplant, trolley frames) with TE129 , the new locomotive also had significant differences:

• two-stage spring suspension ;
• wheel-motor blocks with supporting-frame suspension of a traction electric motor (TED), with the transmission of torque from the TED to the wheel pair through a hollow cardan shaft and an elastic disk rubber-cord coupling developed by VNITI ^[1] ;
• a number of other nodes

The TE125 diesel generator set, like the TE129, consisted of a 2-5D49 (16CHN26 / 26) diesel engine with a power of 4000 l.s. at 1000 rpm, and the synchronous traction generator GS-501AU2, connected by a plate coupling. Dual-circuit diesel cooling system. The ED-121 traction motors were fed through a UVKT-5 rectifier. The drive of the brake compressor, as well as the fans of the refrigerating chamber, TED and the rectifier installation is electric, the generator cooling fan is mechanical from the diesel shaft. ^[2]

The TE125 diesel locomotive is one of the first locomotives in the design process of which a traction drive with a hollow shaft and rubber-cord coupling (RCM) was selected. This traction drive scheme was first tested in 1970 on a TEP10-333 diesel locomotive modernized with the participation of VNITI, and after refinement, it was used in the designs of the TE120 and TE125 diesel locomotives. RCMs had small axial dimensions and, due to this, made it possible to implement a support-frame drive in a diesel locomotive with a wheel diameter of 1050 mm per track of 1435 mm. ^[one]

After completing all the tests, the locomotive remained at the factory. In fact, it was originally created for export to the GDR, as evidenced by the initial designation of the series - 140. But Deutsche Reichsbahn significantly reduces the volume of purchases of diesel locomotives by the end of the 1970s and the beginning of the 80s (including due to the jump in diesel prices fuel). Following the cessation of the supply of TE109, plans to launch the TE125 series are removed from the agenda. ^[3] The USSR Ministry of Railways was considering the issue of TE125 for the USSR railways, but the proposal was rejected due to the fact that in those years it was planned to start the serial construction of TEP70 diesel locomotives . at the Kolomensky diesel locomotive plant . Only in the late 1990s. German railways acquired the locomotive . It was completely restored there, but after 2007 its further fate is unknown. Interestingly, in none of the books of Vitaliy Rakov (the author of a large number of publications on the history of locomotives of the Soviet Union) the TE125 diesel locomotive is not even mentioned.

Currently, 4 diesel locomotives of the TEP150 series, which is largely the constructive successor of the TE129, are operating in the UZ.

There is an opinion that TE125 could be an alternative to TEP70 in train work on the ways of the Ministry of Railways. Both locomotives had a 16-cylinder diesel of the D49 family (2-5D49 and 2A-5D49, respectively), similar traction electrical equipment. Since the TE125 diesel locomotive was created taking into account the technical requirements of European railways, the design team when designing the TE125 had to keep within the grip weight of 120 tf. Such a high weight culture was dictated by the limitation of the axle load, however, on the railways of the USSR, on the contrary, a certain increase in traction weight was increased to increase the traction properties of the locomotive under adverse adhesion conditions. The TE125 traction electric equipment made it possible to realize in a continuous mode the traction force is 20% more than the TEP70 (20,400 kgf at a speed of 39.1 km / h versus 17,000 kgf at 48 km / h), but due to the greater coupling weight (135 t), the TEP70 diesel locomotive in limited mode duration and at low coefficients of adhesion of the wheels to rails could realize great traction. At the same time, the engineers working on the TEP70 note that the indicated 135t of coupling weight is not enough when driving with high generator currents in adverse weather conditions, which forces the use of sand. The design speed of the TE125 was 20 km / h lower (140 and 160 km / h). But given that on most non-electrified lines there was no movement at such speeds, this speed reduction is not so significant.

Among the advantages of TE125, it should be noted the unification with TE109 diesel locomotives already mastered in production, while TEP70 in those years was produced only by experimental batches, as workshops for its mass production were completed only in the mid-1980s. The advantage of TE125 was the electric drive of the fans of the refrigerating chamber instead of the hydrostatic one, which proved to be not the best in TEP70. However, when creating a high-tech diesel locomotive for specific operating conditions, I had to sacrifice some indicators. So, according to the results of traction and heat engineering tests, the efficiency of the locomotive was lower than TEP70. This is mainly a consequence of the use of a number of technical solutions for auxiliary equipment, providing the layout of the locomotive in the 02-T dimension. ^{[4] [5]} Also, during the operation of the TEP150 diesel locomotive with a similar body in the 02-T dimension, there were inconveniences associated with cramped passageways in the diesel room.

• Diesel locomotive TE125 // Lugansk diesel locomotives 1956-2006 / Employees of the Central Design Bureau of OJSC HC "Luganskteplovoz". - Lugansk, 2006 .-- S. 386-393. - 1000 copies.
• TE125: Quiet rival of TEP70 // Semaphore Magazine. - 2004, No. 7. - S. 22-27.