TEP70 (, type 70) is a class of Soviet mainline passenger diesel-electric locomotives with AC-DC electric transmission, manufactured in the USSR and Russia at the Kolomna Locomotive Works from 1973 to 2006. Since 2006, the TEP70BS locomotive, based on this design, was produced. It also served as the basis for the mainline passenger locomotive TEP70U and the dual unit freight locomotive 2TE70. The crew compartment of the TEP70 and a similarly designed body are also used on the EP2K DC electric passenger locomotive.
History
Before the design
Early development The increase in the weight and speed of passenger trains in the 1970s required the use of more powerful locomotives than the TEP60 on certain lines. On the Privolzhskaya, October, and some other railways, 2TEP60 locomotives (or the same TEP60s in double heading) began to be used. However, the use of dual-unit locomotives led to a significant increase in maintenance and operational costs. It became necessary to develop a locomotive with greater power than the TEP60, yet still in a single unit configuration.
In addition, the design of the TEP60 locomotive had a number of shortcomings. In particular, the two-stroke 11D45 diesel engine could not meet future requirements due to its high fuel consumption. The running gear of the TEP60 locomotive provided a smooth ride, but required a significant amount of maintenance.
The design of the TEP70 locomotive started at Kolomna Locomotive Works in 1969 under the chief constructor, Yu. V. Khlebnikov. The design had a weight of with Co'Co' wheel arrangement and a maximum speed of , fitted with 2,264kw (3,975hp) Kolomna DA-5D49 four-stroke V16 diesel engine. Engineers demonstrated that a diesel locomotive with this design was a practical concept.
Visit to the United Kingdom In 1969, it was decided for a Soviet railway delegation from the Ministry of Ways & Communications (MPS) to visit the United Kingdom, as part of a programme of exchange of expert groups. The group was led by Dr N. A. Frufrianskii, who was both deputy director of the All-Union Railway Scientific Research Institute (VNIIZhT) and head of the railway research and test centre at Shcherbinka. The main reason for a visit was to examine the technology and design of British diesel locomotives operating on the British Rail Network, one of them was mostly the British Rail HS4000 "Kestrel" prototype, which was the most technologically advanced locomotive in Britain at that time.One of the visits was to the Brush Traction works at Loughborough, where Kestrel was on display. Frufrianskii’s group was greatly impressed by the innovative features: its AC-DC transmission, electronic control system, electrodynamic brakes, fault indicator system, and a two-stage suspension that made the locomotive suitable for both passenger and freight traffic, the cab design and the level of crew comfort was also far in advance of anything found on Soviet locomotives. Frufrianskii in its own words said "Kestrel incorporated all that was best in world diesel locomotive design and construction, and fundamentally new technical ideas. It was the shape of things to come."
A few days later, at a chance encounter in London, Mr F. Beasant, head of Brush Traction, asked Dr Frufrianskii whether the USSR would be interested in buying the locomotive, Frufrianskii replied cautiously that as a member of a scientific institute, he had no power to make purchasing decisions but undertook to make a report to the MPS on his return to Moscow, which Frufrianskii did, recommending that negotiations should be opened with Brush Traction. The stated objective was to see how the HS4000 locomotive performed under the Soviet railway conditions by comparison with the current mainline passenger locomotive, TEP60.
The unstated objective was to stimulate the Soviet locomotive manufacturing industry where managerial success was measured by building “more of the same” to meet production requirements rather than experimenting with new and untried designs. The MPS took the decision in principle to purchase in early 1971, the question was the amount of money to pay, and to that end a somewhat roundabout approach was adopted.
Kestrel technology examination The locomotive changed its track gauge to Russian gauge, and the cabs were boarded over to protect them during the sea voyage, it arrived at Cardiff Docks and was loaded onto the freighter Krasnokamsk, it was then shipped to Leningrad.
Two series of tests were carried out between 1972 and 1973 to gather comprehensive data upon further aspects of the locomotive. The first were dynamic tests to assess the locomotives' riding qualities and effect upon the permanent way. These tests were carried out on the Ozerskaya branch near Kolomna Locomotive Works and on a stretch of a high speed railway line between Belorechenskaya and Maikop. The second set of tests was on the 6km circuit at Shcherbinka, where the locomotives' power plant, cooling system, electrical machinery and electronic control systems were assessed. Ease of maintenance tests were also carried out.
The technology from the British locomotive was later put into the Soviet locomotive in 1973, incorporating much of the technology from it.
Production The first diesel locomotive according to the new design was built in June 1973. The locomotive was designated TEP70-0001. In 1974–1975, locomotives 0002, 0003, 0004 were built, and in 1977–1978 — 0005, 0006, 0007. The locomotives began undergoing operational tests on the Belarusian Railway. The TEP70-0005 locomotive underwent thermal and dynamic (impact on the track) tests.
The experience gained from the tests provided the designers of the Kolomna Plant with valuable information for making modifications to the design of the diesel locomotive. A decisive role was played by the construction in 1976 of the experimental diesel locomotive TEP75-0001, with a power of 6,000 hp and a 20-cylinder 20ChN26/26 diesel engine, which incorporated the latest solutions at that time in the domestic locomotive building practice, particularly concerning the running gear. Starting in 1978, the plant began the construction of diesel locomotives numbered from 0008, which differed significantly from their predecessors, essentially constituting a new series of locomotives under the former designation (in fact, it was a TEP75 with a simpler diesel-generator 2A-9DG with a 16-cylinder 16ChN26/26 diesel engine producing 4,000 hp, equipped with turbocharging, more in line with the production realities at the Kolomna Plant).
Further modifications to the design were made during production. Three main types of TEP70 locomotives are generally distinguished:
experimental 0001–0007 serial numbers 0008–0185, with vertically arranged marker lights, and riveted panel joints of the bodywork Serial units with No. 0186, with horizontally arranged buffer lights, and a mixed connection of body panels. Among locomotives of the last type, a number of changes were also introduced into the design during production. Prototype No. 0316, equipped with a microprocessor control and diagnostic system with a distributed architecture. serial numbers from No. 0340, with the replacement of the body panels from aluminum alloys to steel and the flooring of the diesel room from aluminum to cast iron. No. 0400 and all series units from No. 0414 onwards are equipped with a standardized locomotive automation system (USTA) No. 0562 is an experimental diesel locomotive designed for sections with steep and long inclines, equipped with gearboxes with a gear ratio of 4.15, as a result of which the design speed is reduced to .
Modifications
TEP70BS In 2002, the Kolomna Plant produced the TEP70A-001 diesel locomotive, which was the result of the further improvement of the TEP70. Compared to the TEP70, it primarily differed by having more technologically advanced body, the presence of the MSUD (microprocessor control and diagnostic system), as well as an electric train heating system (a 3000-volt cable connected to the first car of the passenger train), similar to passenger electric locomotives. In 2003, in honor of the Hero of Socialist Labor — Boris Konstantinovich Salambekov, the TEP70A series was renamed the TEP70BS (Boris Salambekov). Since then, all locomotives of the class, starting from number 002 and onwards, have been produced under this designation. Serial production of the locomotives began in 2006.
In the factory, TEP70BS locomotives initially received a red paint scheme with stylized two-color patterned lines at the front and on the sides, corresponding to the colors of the flag of the country of operation: for Russian locomotives, the lines were white and blue, forming together with the main red at the bottom the Russian flag; for Lithuanian locomotives, they were yellow and green, forming together with the main red at the bottom the Lithuanian flag; for Belarusian locomotives, they were white and green, as used on the Belarusian flag. On the front walls of the cab, these lines have a shape similar to a curved number '7'. On the side walls of Russian and Belarusian locomotives, the curving patterns are located in the cab area and resemble horizontally connected mirror-symmetrical letters 'L', while on Lithuanian locomotives, they are placed near the entry doors on the side opposite the cab with inverted symmetry.Later models of locomotives for Russia were painted in the official corporate livery of Russian Railways, with curved lines of variable thickness (the upper half of the front mask and a narrow stripe at the top of the sides were red, the middle and upper parts of the side walls between the cabs were light gray, and the lower part was dark gray). Uzbekistani locomotives were painted in a similar way, but with a different color scheme — blue at the top and bottom, green in the middle of the sides, with white and red separating stripes between the green and upper blue areas.The TEP70BS locomotive has two main variants, which differ in the gear ratio of the reducers and, accordingly, in continuous operating speeds and design speeds, as well as in the transition speeds to the first and second stages of traction motor field weakening and back. The first version has a gear ratio of i = 3.12, as in the TEP70 locomotive, and a design speed of . In this version were the diesel locomotives of the initial production series and part of the 200 series numbers, as well as some later locomotives with a two-wire power supply system for operating "Lastochka" electric trains, and all export locomotives. The second version features traction gear reducers with a gear ratio of 4.15, as on the experimental TEP70-0562 locomotive, which allows for an increase in the continuous permissible tractive effort at low speeds (for operating long trains on extended ascents in mountainous areas with limited speed), however, the design speed of the locomotive is reduced to . This version constitutes the main production in terms of volume.
The numbering of machines of both design versions is sequential; an indicative list with build dates is provided above.