Russia: Bigger is Better

Written by Alex Luvishis, Ph.D
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RAILWAY AGE, AUGUST 2021 ISSUE: The GEVO12-equipped, three-section 3TE25K2M is among the world’s most powerful diesel-electric locomotives.

Many of the world’s railways use a distributed traction system (Distributed Power) to drive heavy trains. The most common system in North America is General Electric’s (now Wabtec) LOCOTROL. The railways of China and Russia have systems of their own design. Most of their locomotives are six- and eight-axle units equipped with distributed traction.

Distributed traction, which makes it possible to use several locomotives placed throughout a train, allows an increase in train weight and length without increasing the power of a single locomotive. This system began to be widely used on the railways of the world only at the end of the 20th century.

In the early 1950s, the transition from steam to electric and diesel locomotives began in the Soviet Union. But such locomotives were inferior to the best steam locomotives in terms of power, and the first traction force distribution systems were 40-50 years away. Therefore, the task of increasing power was relevant. 

Soviet railways solved the problem of increasing electric and diesel locomotive power with two-section locomotives. The first of these were the electric locomotives of the N8 series produced at the Novocherkassk plant. The first two-section diesel locomotives were TE3s produced at the Kharkov plant.


Later, the Soviet railways began to produce three- and four-section locomotives. The most powerful diesel locomotive produced in the 20th century was the 4TE10S 24-axle diesel locomotive with an output of 8,824 kW (11,833 hp) produced at the Luhansk plant in 1983. The length of the locomotive was 68 meters (223 feet); the adhesion weight was 414 tons. A total of 25 4TE10S units were produced; they operated on the BAM (Baikal-Amur Mainline).

Chinese HXN5

Multi-section diesel locomotives are still used on RZD (Russian Railways). The modern fleet of freight diesels consists of 75% 12-axle, 15% 18-axle, and only 10% single-unit. About 33% have an output of 4,500 kW (6,000 hp). The most powerful diesel locomotives in China are the HXN3 (4,700 kW, 6300 hp) and HXN5 (4,660 kW, 6,250 hp). The most powerful diesel locomotives in India are the WDG6G (4,470 kW, 6,000 hp). In the 21st century, the need to increase the power of Russian diesel locomotives is determined by an increase in the weight norm of trains on BAM. 

Russia’s largest railway is the fully electrified, 9,288 km (5,760-mile) Trans-Siberian Railway. BAM is the second-largest, at 4,287 km (2,660 miles). This railway runs north of the Trans-Siberian, and in some sections parallel to it. It begins at the Taishet station, bends around Lake Baikal from the north, crosses the great rivers of Siberia in Bratsk and Ust-Kut and the Amur in Komsomolsk on the Amur. The terminal station is Sovetskaya Gavan, located on the Pacific Coast.

BAM crosses seven mountain ranges and 11 large rivers, with no fewer than 2,230 bridges. The highest point is the 60-km (37-mile) Mururin Pass at an altitude of 1,323 meters (820 feet) above sea level, with a steep ruling grade. The 838-km (520-mile, about 20% of the BAM) Taishet-Ust-Kut section is electrified with 25 kV, 50 Hz AC, so about 80 requires diesel locomotives.

Ambient temperature varies greatly. The average annual air temperature is only 7.8 degrees C (46 degrees F), and the absolute minimum is –58 degrees C (–72.4 degrees F). It is below 0 degrees C (32 degrees F) between 196 and 209 days annually.

Revenue service on the BAM began in 1984. In 2014, with 3TE10M diesel locomotives, maximum train weight was increased to 4,900 tons. In 2017, with 2TE25A and 2TE25K units, train weight increased to 5,600 tons. After 2017, the task was set to increase maximum train weight to 7,100 tons. For this, the 3TE25K2M “Peresvet” diesel locomotive was commissioned. To improve reliability and increase power, GE GEVO12 engines produced in the U.S. were installed.

The 3TE25K2M Peresvet is a Russian main line three-section diesel locomotive with six-axle sections (18 axles total), AC-DC electric transmission and DC collector traction motors. It was produced at BMZ (Bryansk Machine-Building Plant). Each section uses a 12-cylinder, 3,100-kW (4,157-hp) GEVO12 engine with a nominal speed of 1,050 rpm, a traction alternator of Russian production (created as an alternative to generators previously manufactured in the Ukraine), and 18 traction motors with a capacity of 350 kW (470 hp) each. Total power is 9,300 kW (12,645 hp); starting traction effort is 838 kN (188,400 foot-pounds). The design speed is 100 kph (62 mph). All this makes the 3TE25K2M among the most powerful diesel locomotives in the world.

The assembly of the first two 3TE25K2Ms was completed in February 2017. In March 2018, upon completion of the main test cycles, a certificate of conformity was obtained that allowed starting the planned serial production of locomotives of this series in three-section and two-section versions.

Traction and energy tests of the 3TE25K2M were completed in early 2021. As of January 2021, 54 units have been manufactured. Unfortunately, due to possible sanctions imposed by the U.S. against Russia, diesel engine supplies from Wabtec may be discontinued. Under these new conditions, the only way to develop RZD diesel locomotives would be 100% localization. 

RZD leadership has turned to Sinara Group and the Ural Locomotives plant to construct new diesel locomotives. Thanks to Sinara’s efforts, within a short period of time, the 2TE35A was developed, with operation to begin in 2022.

Yet another version: The 2TE25A main line two-unit diesel freight locomotive, rated at 5,000 kW (6,705 hp), with AC/AC transmission and individual axle traction control. The
2TE25A has been configured on the basis of the previously developed 2TE25K class Peresvet main line two-unit diesel freight locomotive of the same power rating and featuring AC/DC transmission and collector traction motors.

The 2TE35A is a Russian freight main line, two-section, 16-axle diesel locomotive with two eight-axle sections, AC-DC-AC electric transmission and asynchronous traction motors. Length is 48 meters (158 feet). The carbody of each section is supported by two four-axle bogies. The locomotive uses a 16DM-185T diesel engine with an output of 3,650 kW (4,895 hp) developed by UDMZ (Ural Diesel Engine Plant), and 16 TAD430 430 kW (577 hp) AC traction motors. The 6DM-185T is 18% more powerful than the GEVO12 and 38% more than the Russian D49 engine. Total power is 7,300 kW (9,900 hp). Design speed is 120 kph (75 mph). The 2TE35A is designed to haul freight trains weighing 7,100 tons along the BAM. 

RZD has decided to purchase 200 2TE35As by 2031. Trial operation is scheduled for 2022, followed by series production at UMDZ. 

Alex Luvishis, Ph.D. for 18 years headed the laboratory that developed control systems for Russia’s first electric locomotives and asynchronous traction motors in the former USSR. For a further seven years, he headed the rolling stock department at the Institute of Technical Information of Railway Transport in Moscow. Dr. Luvishis is the author of more than 100 articles on electric traction drives and the book “Hybrid Rail Vehicles,” published in 2009. His interests are asynchronous traction drive systems for modern rolling stock, and hybrid drive systems for trams, suburban and regional trains and switching and main line locomotives. He has lived in the U.S. since 1999. 

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