E68000 Mainline Locomotive

The E68000 series electric locomotives are modern, multi-purpose mainline locomotives operated by the Turkish Republic State Railways (TCDD) and designed to operate on a 25 kV AC voltage system. Developed through a collaboration between the South Korean company Hyundai Rotem and the local manufacturer TÜLOMSAŞ (now known as TÜRASAŞ), these locomotives have played a critical role in the modernization of railway transportation in Türkiye.

The E68000 project was initiated by TCDD in the 2000s to meet the growing demand for rail transport by introducing electric locomotives with higher tractive effort, improved energy efficiency, and modern technology. The first eight locomotives were manufactured by Hyundai Rotem in South Korea. The subsequent 72 locomotives were produced locally in Türkiye at the TÜLOMSAŞ facilities in Eskişehir using a phased licensed production model. Thanks to this production and technology transfer process, Türkiye developed domestic manufacturing capability while reducing its dependence on foreign suppliers. According to TÜRASAŞ data, serial production was completed by 2015.

The TCDD E68000 series electric locomotives feature a high-efficiency traction system designed to operate on a 25 kilovolt 50 hertz alternating current (AC) supply. They are fully AC-driven, with motor control and speed regulation managed by digital drive systems. Built on a four-axle (Bo′Bo′) configuration, these locomotives are specifically designed for passenger and medium-weight freight services.

The locomotive’s continuous power output is 5,000 kilowatts, enabling a maximum speed of 140 kilometers per hour. Its body weighs 86 tons and provides both low axle load and a track-friendly ride profile. Thanks to regenerative braking, electrical energy generated during downhill runs is fed back into the grid, significantly improving energy efficiency. The E68000 features a dual-cab design, allowing operation in both directions. Additionally, modern equipment such as air conditioning, fire detection, and automatic suppression systems have been installed to enhance driver comfort. The braking system combines electric regenerative braking with pneumatic (air) braking, ensuring both rapid and safe stopping performance. Although some tractive limitations have been observed when operating single units on steep gradients or under heavy loads, performance is effective in double-locomotive operations. Furthermore, its modular design enables easy and rapid maintenance procedures.

^{E68000 Locomotive (Generated by Artificial Intelligence)}

The E68000 locomotives were designed for both high-speed passenger trains and medium-to-heavy freight trains. In their initial years of service, they were primarily used for passenger transport. The locomotives’ regenerative braking capability enhances energy recovery and contributes to environmental sustainability. However, technical analyses have indicated that their four-axle configuration imposes limitations in tractive performance when hauling heavy freight trains on steep gradients. Particularly with loads exceeding 3,000 tons, wheel slip issues have been observed. As a result, double-locomotive operations are frequently recommended for freight services. On the other hand, TÜRASAŞ has implemented both software and hardware upgrades to address these issues. These updates have improved traction control systems and increased the locomotive’s hauling capacity. The locomotive’s suitability for both passenger and freight operations supports a versatile operational strategy, while its ease of maintenance and modular component structure facilitate fleet management.

The E68000 electric locomotives represent one of the most significant steps in Türkiye’s transition to domestic rail production. This series, developed by adapting Hyundai Rotem’s technology for local manufacturing, has added a modern, environmentally friendly, and high-performance component to TCDD’s electric locomotive fleet. Despite initial performance challenges, ongoing technical upgrades have enabled the E68000 locomotives to remain actively deployed on many mainlines today, fulfilling a strategic role in Türkiye’s railway transportation network.

^{TCDD E68000 in Operation} (Veli Ugur Sener Academy)